Photo courtesy of Icynene.com
Remember, my Top 10 This Next List , where I posted my ten favorite green building products? Number 5 on the list is Icynene®, an open cell spray foam insulation. It basically provides a barrier to prevent drafts, condensation, and outdoor allergens from penetrating the building envelope. From personal experience, this is an amazing product.
Icynene® was installed inside the cavities of our exterior walls including the basement walls. I have a geothermal system and swear that my energy bills are so low because of the combination of the two. I run my house at 76 to 78 during the summer (but at 74 at night on the second floor) and am quite comfortable. In the winter I run the house at 68. My air conditioning never runs in the basement and it never feels humid.It is expensive compared to the other insulations. A couple of years ago, I paid $1.40 for a board foot (northeast prices). A board foot is a 1 foot by 1 foot by 1 inch thick square. For my area, it is recommended that there is 6 inches of depth in each cavity wall. (Each board foot is equal to R 3.6) However, in my opinion this insulation is a superior product to fiberglass or other insulations because of the air barrier.Why open cell versus closed cell? Closed cell is denser and therefore more expensive. However, it has a higher R value than an open celled insulation. We chose open cell insulation because we were told that the closed cell insulation off-gassed chemicals. This may or may not be true at the time we installed our insulation, but I was frightened by the prospect of this being true. In addition, if there was a water leak, I would find it easier with an open cell insulation because water can move through it unlike closed cell. Some people prefer closed cell because of its higher R value and it provides a better air barrier.
Icynene has two different applications depending on whether its use is for new construction or touch-ups. Icynene Insulation System ®, which is used for new construction and major retrofits, has two different formulas: sprayed and pour. “Icynene®’s pour fill variation is an insulation and air barrier that injects the latest building technology into an older building to maximize energy efficiency while still preserving its original architectural details,” according to the makers of Icynene® To view both the spray and pour systems in action, view the videos here. If you have a small project or need a touch up, then Gold Seal 400 ® is the product you would use.
In addition, on their website, there is a chart comparing different insulations to Icynene in certain categories such as damaged by water, R value, and whether or not there are any harmful emissions produced after installation is complete. (Remember, this chart is produced by Icynene, not a third party, so use it as a guide.)
Does it have a downside? Icynene® is a petroleum based product. You may or may not view this as a downside.
There are soy-based foam insulations, but I do not have any experience with these products. When we were looking at the different insulations, soy was getting negative publicity. (I heard it was shrinking inside the walls so the stated R value was diminished.) Was this a marketing effort by the other insulation companies? I don’t know. Does anyone have any experience with the soy-based insulations?
For additional reading about the varying type of insulations, Homepower.com has a nice article. See “Get Energy Smart Insulation Options” written in March 2006.
Regardless of which insulation that you choose, the actual installation is the key. If any insulation is installed improperly, it does not matter what its stated R value is. Obtain recommendations from people who have used your intended installer. In addition, read the literature on the product you are intending on using to familiarize yourself with how it is supposed to be installed. An educated homeowner is a happy homeowner in the long run.
I would love feedback on open versus closed cell insulation, and the product you like best and why.
Ragnar says
I’m a contractor and have subcontracted to have Icynene and Corbond (a polyurethane spray foam) installed on a number of my projects. I like them both and would not hesitate to use either one of them. I have Icynene in my own home and have been completely happy with it.
Corbond is about R7 per inch (almost twice that of Icynene), so sometimes code requirements have forced us to use this instead of Icynene when dealing with a limited installation volume. However, Icynene is usually less expensive on a cost per R-value basis.
The only real downside to the spray foams is cost. (Corbond is about $1.00 per board foot in the Seattle area — I’m surprised your market for Icynene is as high as it is!) However, they completely outperform fiberglass on many levels. As you mentioned, they are very effective at stopping air infiltration. Also, they do not signifigantly lose R-value at low temperatures (R19 fiberglass at 18 degrees under moderate wind pressure drops to an R7 rating, for example).
Green Talk says
Ragnar-thanks for the comment. Corbond is a closed cell spray insulation. I tried to find out if there was any offgassing of the product via their website. All it said was it was Corbond is made of “resins similar to popular polyurethane varnishes for wood.” Did it smell when you installed it in houses you built or renovated? I always remember the warning I received about the offgassing of closed cell insulation. Have you heard this too?
I also learned that you can’t add Corbond to the inside of your walls after they are closed up.
Why did you decide to use Icynene over Corbond for you house?
I am curious as to Icynene’s board foot installation price in Seattle. Everything in the northeast is very expensive especially the tri-state area (areas close to NYC).
Please post again because I love hearing from contractors who have used eco-friendly products, and whether or not they like them. If you have some great stories about jobs that you had to fix, please post them on “If I only knew” page.
For our readers, do you build sustainable houses? If so, leave your “url” for our readers or an address for them to contact you in the Seattle area.
Brian says
You mentioned geothermal in the Northeast and I am curious to see how it works in this area. I am building a house in Mass and interested in geothermal, solar, and Incyene. I know this is a discussion on Incyene, but I have some questions about Geothermal. How much did it cost to install? How big is your house? Did you run into any issues (IE Blasting ledge) and last but certainly not least, how long have you had it and have you had any maintenance issues?
Brian’s last blog post..Episode 7 – The Marketing Show
Green Talk says
Hi Brian-you have asked some very important questions and I have a mouthful of suggestions about my geo. Since I built about 3 1/2 years ago, my prices to build my unit has gotten more expensive. Water Furnance has also manufacturered better units since mine (more efficient). I am going to call my geo people and see if they can give me a per sq ft price for you. In addition, I will write a post this week about what I learned. I could probably easily write a page what I would have done differently but the bottom line is I would never trade my geo for the world! Can you hold onto these questions until next week? anna
PS where are in you construction?
Brian Murphy says
We are breaking ground next week, but want to make sure I do this right before getting into it. I can wait untill next week, but hoping you can answer one quick question. How far down did you dig for the loops? I am building in Reading, MA 20 miles north of Boston.
Green Talk says
Brian-I wrote a lengthly post for you. Don’t fall asleep reading it. I hope it helps. See my current post, http://www.green-talk.com/2007.....ownership/
Gary L. Maedl says
Hi. I am a Mechanical Engineer (with a minor in Polymer Chemistry) and also an Architect. I have been designing and building homes with High-density Polyurethane foam insulation since 1975 and Geothermal Water-source heat pump systems since 1978. I can assure you that High-density Polyurethane does NOT outgas. If you want to prove this to yourself, purchase a can of “Great Stuff High Expansion Foam” (not the low expansion stuff) from Home Depot, spray it in a pile in a warm area, and let it cure for at least 24 hours. You will notice a smell when spraying; this is from the chemicals (part A and B) interacting with each other. Once the chemical reaction finishes, the gas is gone. So, when you break your foam in half you will not smell the gas (depending upon how long it has cured). Note also that if you take this foam block and put it in water, it will not absorb any water and will float there forever. That’s why they use it to line boat hulls. In contrast, Icynene will absorb the water very quickly and sink. This is the problem with Icynene and it must be installed with a water/vapor tight barrier on BOTH sides in order to work properly. Otherwise it will absorb moisture from inside and outside the home and, when wet, will have minimal insulating value and will promote mold growth.
Bert Echterling says
I am an installer of Icynene and I have to speak against the post of Icynene absorbing water. A field test will show that Icynene will float on water indefinetly and NOT absorb water. In fact, Icynene is the ONLY open-cell foam that does not absorb water, YET does let it pass through without absorbtion. If in doubt, please find some and test. Before getting into the business, I personally field tested and/or watched EVERY spray on the market at the time. I am a firm believer in Icynene. My foam business is a third business I started and I wanted only the best….Icynene is it!
Jonathan says
Hi Bert,
I couldn’t agree more with you. I have sprayed closed cell polyurethanes, open foams and now only spray icynene. This product is excellent and with a GWP of only 1 it does its bit for the environment unlike some of the other foams with a GWP of 900+ I can second that Icynene will NOT absorb water but let it pass through and dry out without loosing its thermal values (unlike other foams i have sprayed)
Green Talk says
Bert, thanks for including your 2 cents. I had a leak in the foundation wall where the icycnene was and the water pass right through it. What do you think of the soy sprays or demalac (spelling?) Anna
Gary L. Maedl says
Dear Bert,
I am sorry but your field test results have mislead you. Icynene DOES absorb water and will sink if left floating in water long enough.
To prove this, take some icynene, weigh the piece on an accurate scale (i.e.- postal meter), put it in water over night, and then weigh it again. You will see that it has gained a significant amount of weight. This is absorbed water.
My high density rigid polyurethane installer was recently hired to fix a cold storage facility in Massachusetts where the contractor bid the job that specified as high density polyurethane, but installed icynene instead. Within a few months, the water was actually running down the walls and the R-value had gone to zero. It had to all be ripped out (by my friend), the building dried out, and then reinstalled according to spec.
Green Talk says
Welcome back, Gary. Anna
Laura Pollak says
Greetings all, been reading the posts re Icynene and water. We were very excited to have the product installed and have noticed good utility bills. BUT we had a leak and it has taken 3 years to find the source because the Icynene was holding the water. Now we have found not only the leak, BUT we’ve found MOLD too. The foam was saturated. We wrung it out like a sponge. It held so much water that we needed buckets and dehumidifiers to let it all drip out and collect. Then we found some very nasty mold; stachybotrys, black mold. The comments on the Icynene websites are total lies. This stuff is like a sponge and held the water right up against the wood and the foam even had mushrooms growing out of it! It does not let the water pass right through, it wicked it. I tried an experiment in my kitchen and took a cup of water, added 1 drop of green food coloring then put in the foam. It turned green on the bottom and soaked up so much water that when I took it out after a half hour, it behaved like a sponge. Please let me know if you have any experience that sounds like this or if there have been any lawsuits regarding this issue. We have 3 bathrooms that we now have to tear out!!!!
Many thanks,
Laura
Laura Pollak says
By the way, I have pics at the following site; http://icynenedangers.blogspot.com/
Laura Pollaks last blog post..Icynene Lawsuit/ Litigation
Green Talk says
Laura, thanks for the comments. I have not had that problem but this is something I should look at for. I am wondering if the same thing happens with the other foams such as soy or closed cell? Keep us apprised of your litigation. What is icynene saying about all of this?
Gary, if you are reading, any thoughts about both (soy and closed cell with regards to water.) I know you like the closed cell. Anna
Gary L. Maedl says
Laura- Your experience with Icynene is exactly what I would expect. I know of many similar stories about this product and am sorry for the troubles you are experiencing. Do not let these lying Icynene SOBs try and trick you with some sort of “fix” or blame you because there was a leak.
It does not require a leak for Icynene to absorb water and start to propagate mold. Normal moisture transpiration in the home will have the same effect, except it takes a longer period of time than a direct leak. The only solution is to rip the Icynene completely out and replace with rigid polyurethane.
Anna- With respect to the Soy or other organic based foam insulations, you will have even worse problems than with Icynene. Soy (organic) based foam is not stable. It will shrink over a fairly short period of time and take surrounding surfaces with it. It will also absorb water like crazy, and the composition of the foam makes an ideal “food” for the resultant mold growth.
Over time, even if it behaves well in every other aspect, Soy and other organic based foams will decompose. They are ORGANIC, so they rot. Sure, there are inhibitors in the foam to retard this process, but after some number of years, the foam will simply turn to dust.
Why not just bite the bullet and use rigid polyurethane foam? It is a plastic that does not degrade, absorb water, rot, or deteriorate.
Laura Pollak says
Greetings again,
Had a 2 hour meeting with attorneys and construction specialist. Looks like they want to have a nice talk with Icynene. I gave them my sample of the product that soaked up water like a sponge just sitting on top of the glass. Also showed them the pics of mold growing out of the Icynene. Will keep you all posted. In the meantime, you can see my blog on the subject at http://icynenedangers.sampasite.com
If anyone knows of other lawsuits or such problems, it would be very helpful. Surely we’re not the only ones that have had to go through this!
Many Thanks,
Laura
Laura Pollaks last blog post..Icynene Lawsuit/ Litigation
Tony B says
What about a hybrid combination of 1 inch closed cell foam against exterior plywood to stop air infiltration and fiberglass for the rest of the cavity? I wonder about condensation and possible mold problems due to the fact that water that gets into the wall will have nowhere to go. Has any one had this done?
Green Talk says
Tony B, I am not sure how much the 1 inch would help against air infiltration. It is my understanding that moisture (like condensation not a leak) can not get through with closed cell. Gary, are you reading Tony’s comment? Anna
Green Talk says
Laura,
Thanks for keeping us informed. I know you have a blog (which I checked out.) Would you mind, giving us some updates? I would love to hear how Icynene answers the sponge issue. Anna
Gary L. Maedl says
Tony B- You are right. There are many people who are combining 1″ (or 2″) of closed cell high density polyurethane insulation for the outer surface (on the inside of the exterior sheathing), and then completing the insulation with fiberglas or cellulose. They do this to save money over doing the whole job with urethane.
This 1″ will stop the infiltration. It is very powerful stuff. And the fiberglas insulation will get you there in terms of overall R-value. (I personally don’t like cellulose- water absorbtion issues again.)
But I do worry about the stratification of the insulation. In other words, you have this heat trying to escape the home. It is traveling through the fiberglas with a value of about R2.5 per inch and with no anti moisture migration capability. Now it suddenly hits the urethane with an R7 per inch and total moisture migration prevention. What happens here? Does moisture build up on the inside of the urethane? I don’t know. That is why I always spend the extra few thousand dollars and use urethane all the way through.
Of course, with any well insulated modern home, you need to have an HRV or ERV unit in the home to take the moisture out and bring fresh air in without loss of energy. If the HRV or ERV is properly set up, then you should not have any mold or mildew issues.
Tony B says
Yes, I just installed my HRV system and am soon to insulate. If the 1-2″ of closed cell foam stops air from leaking out of the house (and visa versa) then in the winter hot moist air will not continually be escaping and condensing against the exterior sheeting, lessening the fiberglass R-value and possibly causing mold and rot. If the closed cell foam efectively stops air infiltration wouldn’t the moisture content within the wall be equal to that of the inside space, which is controlled by the HRV? I would sure like to see some studies on this or hear of anyone with experience with this hybrid system before I do it.
Laura Pollak says
Hi Guys, been watching these conversations and have to ask the following… If the Icynene is sprayed on the ceiling rafters and actually covers the soffit openings can I have the house washed without soaking the foam? Can I have the windows cleaned without the pressure washer getting water into the foam by the soffits? Another question… we just got a report from a structural engineer… are there supposed to be weep holes above windows? We have very few weep holes and this is a 3 story house with large windows? Also, is head flashing supposed to come out 2 inches beyond the brick veneer?
Many thanks for the expert info!
Laura
Laura Pollaks last blog post..Icynene Lawsuit/ Litigation
Gary L. Maedl says
Tony B- The moisture content in your home is constantly changing with the weather. It changes rapidly with doors/windows opening/closing and with things you are doing inside (showers, dishwasher, laundry, etc.).
The air inside the wall (between the drywall and the close cell foam) is essentially the same moisture content as that of your home. But it does not change rapidly due to the fact that it has to migrate through the drywall to get into that space. And once it gets wet, it tends to stay that way.
Mold needs 3 things: moisture, warmth, and no moving air. The space occupied by the fiberglas meets all of these criteria. However, the fiberglas itself may mitigate mold growth; I don’t know.
Lisa Rankin says
Gary,
We are building a home in Houston, Tx. I would like to use very energy efficient insulation. I’m concerned about the water issues with icynene which has been suggested to us. Which insulation would you recommend and for which locations? You mention High-density Polyurethane foam insulation, what brand name would that be? I would really appreciate your help, I am extremely frustrated with the lack of substantial, truthful information.
Thank you so much in advance.
Lisa
Gary L. Maedl says
Lisa- There are many different manufacturers of high density rigid polyurethane foam insulation. The best known one to me is Corbond ( http://www.corbond.com/ )
Although this might be a little technical, I think that you might find this link to the “Center for Polyurethanes Industry” most interesting and helpful: http://www.polyurethane.org/s_.....8;DID=3622
You asked, “…which insulation would you recommend and for which locations…”. From my point of view, using sprayed in place (goes on with a spray gun as a liquid) high density polyurethane or polyisocyanurate rigid insulation is the best insulation money can buy and, in the hands of the right installer, can be utilized throughout your home- walls and ceiling/attic. However, it must be covered with a fire barrier (i.e.- drywall) of at least 15 minutes per most local building codes.
The best way to make sure that you get the right stuff and that it is installed correctly is to select an experienced and well respected spray foam installer. Make sure to ask for references, several of them, and ask about their experience with insulating cold storage buildings. (Hint: If they have no cold storage experience that they can reference, they are not the right person for your project.)
Steve says
I’ve noticed a bit of my icynene against a rafter is sort of powdery now and brownish…had wondered if it had deteriortated from a water leak possibly. Also has anyone noticed if the smell lasts with this stuff? My wife can’t smell it but in closed closets with the stuff in the walls around it, I can smell something and think it might be the icynene 3 years after its been installed.
Gary L. Maedl says
Steve,
The “powdery brownish” state that you see is the Icynene decomposing from exposure to air, or it could be being eaten by bacteria (which need moisture that the Icynene has absorbed and are eating the organics in the foam).
Icynene, as I have stated before, needs to be covered and should not be left exposed to air. (The same is true for rigid polyurethane, but for fire regulation issues, not decomposition from air or bacteria issue.)
I would suggest that you call in a reputable, experienced foam installer to have a look and make a recommendation on how to fix this. To stop further decomposition, you will need to seal it somehow.
As for the smell, it disapates within a very short time after installation. What you might be smelling (if it is a chemical type odor) is the residual smell from dry cleaned clothes.
If you want to rule out the Icynene, cut a small hole in the wall cavity of a closet (from stud to stud so you can patch it easily) and stick your nose in the hole to see if the smell you are sensing is stronger inside of the wall.
Olivia Jones says
We are building a home in Portland, OR. Please let us know the best insulation in the market at this time.
NEED HELP!
Marc says
After looking at the pictures of the mold problem I can tell you from many years of working with construction defects and mold issues that Icynene is not the problem. If you had fiberglass in that ceiling the mold would have been 1000% worse.
If you sprayed the inside of a swimming pool with spray foam and filled the pool with water, is the foam trapping water? No… the water has no place to go. Drain the pool and watch the foam dry it’s self out.
Gary L. Maedl says
Olivia- Refer to my August 11th comments above for the best insulation, rigid polyurethane foam.
Marc- In my professional opinion, your comment that the mold would have been worse is not based in fact. Icynene absorbs water; end of story. Fiberglas does not, although like any fiber, water will cling to its surface and it will “hold” water.
With regard to your swimming pool example, yes, the foam IS trapping the water. Otherwise it would quickly drain into the surrounding soil (assuming an in ground pool).
The point of all this is that if the spray foam you used was Icynene and you let the pool water stand for a day or so, the level would drop as the water migrated through the Icynene into the soil and the Icynene would be soaking wet inside. If you then drained the pool, yes, the foam would eventually dry out (after many weeks with no rain, etc.), but only to the point of equal moisture content with the surrounding soil on the soil side of the foam and to the point equal to the air’s humidity on the air side of the foam.
If you used rigid polyurethane, the water would, in fact, have no place to go since it cannot penetrate the polyurethane surface. The water level would remain the same (except for evaporation) until you drained the pool. There would be no need for the foam to “dry out” since it would not have absorbed any water.
As I’ve stated before, this can be proven by submerging a preweighed sample of Icynene and a preweighed sample of rigid polyurethane in water for a period of time, and then weighing the samples (after drying their surface) to see if they gained any weight. The Icynene will gain substantial weight (water) while the rigid polyurethane will not gain any.
With regard to mold issues, any material that will absorb and hold moisture and has an organic component will support mold growth under the right conditions.
Green Talk says
Gary,
Do you think all open cell foam insulations would have similar problems as icynene? Anna
Olivia Jones says
Hi Gary:
Thank you very much for your response.
1) Corbond does not have any dealer in Oregon, please recommend another rigid polyurethane foam manufacturer.
Thank you.
Tim says
Hi guys,
I found this site searching for what to do about our insulation… I live in a 150 year old house in Northern VA. The walls have are lathe and plaster and have no insulation. We are ripping off the old siding and replacing it, and are trying to decide which insulation to go with. Any suggestions? Could we do a combination of foam and fiberglass? How can we avoid the moisture problems being discussed?
Thanks,
Tim
David says
Would you recommend this type of insulation for hot and humid areas? Texas gets pretty hot and energy bills can be pretty high. Also, is Icynene good for attic insulation? Thanks for the article.
Gary L. Maedl says
Anna- Yes, all open cell foam will have the same problems. They are structured internally the same as a sponge.
Olivia- I am not familiar with any other manufacturers other than Dow Chemical. You can refer to the Polyurethane Manufacturers Org link that I gave above, or simply contact local foam insulation contractors in your area and quiz them based upon what has been discussed here.
Tim- Rigid polyurethane is ideal for remodeling old homes, but only if you can expose the inner side of the exterior sheathing so that the foam can sprayed on this surface correctly. You cannot put this foam into an enclosed cavity without risking it expanding too much and pushing off your interior wall and/or sheathing/siding. There are low expansion mixtures of rigid polyurethane that you can use, but you would have to find a very experienced installer to do the work. DO NOT remove the exterior siding and spray the foam on the exterior side of the lathe as this will cause you nothing but problems. If you have removed the interior wall lathe and plaster, you could go with the foam and fiberglas combination that I’ve discussed previously. You will not have any moisture issues with rigid polyurethane.
David- Once again, rigid polyurethane is the best insulation solution. Icynene, in my opinion, is not good to use as an insulation in any case or place, but can be used in walls if a sealed vapor barrier is installed on both sides of the foam. Icynene should never be used in an attic, ever.
Melody says
I just had Icynene installed last week by an authorized installer. Today I noticed that the Icynene is shrinking back from the studs, causing gaps. It’s a Sunday, so I’ll have to wait to call the installer tomorrow. Trying to figure out what can be done, & hoping I didn’t make a big mistake by choosing this product. I’ve read one of the previous posts about mold & starting to really be concerned. Should I have my installer rip it all out & replace it with the rigid stuff?
Any & all opinions welcomed.
Melody in NC
Green Talk says
Melody, did you call your contractor to asked what happened? I would also call Icynene tech and tell them this as well. Shot them a picture. This did not happen to me. Let us know the outcome. Anna
Gary L. Maedl says
Melody,
Shrinkage can happen when either (a) it is cold outside or the studs/wall surface were cold from the previous night and they installed early in the morning without letting the wall warm up, or (b) the mixture of the chemicals A & B was not correct.
If it pulled away from the studs at the sides, it most likely pulled away from the sheathing as well. I would make the installer rip it out. As always, I would have used rigid polyurethane, not the icynene.
Melody says
Thanks for the fast reply. We called the installer & they admitted to a “bad batch” that day. They will call back within a day or 2 to schedule another installation.
Question: Is it OK if a thin layer (1-2 mm) of the “bad batch” is left on the studs or shall we insist that all residue is removed so that the foam can adhere properly?
Melody in NC
P.S. I have contacted Icynene, but have yet to hear from them.
Green Talk says
Melody, I would ask to speak to someone in Icynene’s technical department and not wait for a call back. Tell them you need an immediate answer and then tell them what ooccurred and your further questions. Don’t get off the phone until you get an answer. Let me know their answer. Anna
Gary L. Maedl says
Melody,
If the foam is stuck to the wood (will not come off easily using your fingers), then it is OK to leave it. The new foam should dissolve the old (if it is just a thin layer) and bond strongly.
On the other hand, if you can peel it off with your fingers, then it has to be scraped off down to the wood.
For a correct installation, the foam should be “bonded” to the surface of the wood.
Good luck.
Green Talk says
Gary always gives very sound advice. Anna
Arvid Metcalf says
You don’t know how thankful I am that I stumbled on this website and discussion. We have a sips house but need insulation in the garage and the outside wall of a walk out basement. We are almost ready for the insulation and found it was hard to justify the icynene price so we decided to go with blown in wet cellulose. It looks like getting the cellulose company here may delay the house by up to two weeks so I ran a little experiment to see if we could use a plan B. I ran a bead of Great Stuff around all the joints of a cavity (2X4s with OSB sheathing) and it looks like it will do a good job of stopping any air infiltration I then thought I would put 6 inches of fiberglass with no vapor barrier into the cavity and then install the dry wall. Does this sound like a reasonable solution? Thank you for all the education you have given me.
Green Talk says
Arvid, where are you located? Gary, any help? Anna
Arvid Metcalf says
Thank you for responding. We are located just South of Lexington, KY.
Gary L. Maedl says
Arvid,
Your use of “Great Stuff” (rigid polyurethane) to seal the joints, gaps, etc., and then use 6″ of fiberglas is better than fiberglas alone. But your comment of “no vapor barrier” worries me.
Can you put Tyvec on the outside of the sheathing? Or you might want to staple plastic to the inside of the studs to form a vapor barrier. Vapor barriers are important to limit moisture migration; from inside out and outside in, both.
“Great Stuff” is great, but it is expensive to use when doing a large job like yours. For the future, I would suggest using commercially available DIY spray foam kits such as from Tiger Foam ( http://www.tigerfoam.com/ ). It will do a better job, save you a lot of money, and prevent “finger blisters” from squeezing the trigger on the can.
Arvid Metcalf says
Thank you for your prompt help. The exterior walk out wall of the basement that is in question is actually a double wall. A 2X6 wall that supports the 6 inch SIPS panels for the first floor and then about 1 inch inside of that wall is a 2X4 wall that supports the I joists for the first floor. The outer wall is sheathed with OSB with Tyvek and vinyl siding. The inner wall will have ½ inch drywall. I have heard is it not good to have 2 vapor barriers because moisture that somehow gets between them has no way to get out. When making the cavities so tight with the foam insulation I am afraid of putting a vapor barrier on the inside and trapping moisture in the insulation. I don’t know if it is relevant to this discussion but we are having geothermal with a separate energy recovery unit installed. We will also have dehumidifiers for the humid days in the summertime. Do you think we should go ahead with a plastic vapor barrier on the inside too? Thank you for your heads up on the Tiger Foam website. I think we will be making good use of it.
Jon F. says
I was wondering if anyone has any opinions on AirKrete. I have been doing some reading and from a safety standpoint it seems pretty good. Great fire resistance as well.. any thoughts would help since I am trying to decide between Icenyne (low probablility), a polyurethane foam (medium probability) or other ideas. Thanks! Jon
Barbara says
I see that this is an old post, but Im going to reply anyway. We have Airkrete in our home and LOVE LOVE LOVE it. Its early December 46-57 outside and we still havnt turned on the heat. Its 70 inside. Airkrete has some of the best R-value per inch, sound proofing, wont burn, wont off gas, no end of life issues, pest resistance, etc. . . That said no insulation is perfect. Poly foams can turn your house into a death trap of toxic fumes in a fire. Airkrete is heavy and goes in wet. If you are thinking about installing it I would recommend doing it in the driest/hottest months of the year. We installed in October and just barely got it dry before the wet season and wouldnt recommend installing that late in the year to anyone. We also have it in our ceiling but know of 1 persons ceiling coming down because of the weight when wet. Once its dry its not much heavier than regular insulation. Best choice when used correctly.
Anna@Green Talk says
Barbara,
Some posts are evergreen meaning it doesn’t matter about their age. In fact, I wrote about AirKrete. I love that your experienced it. I like the flame retardant issues of AirKrete. Would love it you could also post a comment over on my AirKrete post. You might also see if you can answer some of the questions over there.
See http://www.green-talk.com/2010.....rgy-bills/
Jen says
Hi All,
Thanks for all of the great info about insulation. One clarification question: we are renovating a 1913 home in Ohio, no insulation in walls (plaster and lath), no vapor barrier in walls (wood siding covered wiht alumnium siding). Is there ANYTHING I can insulate these walls with without ripping out the plaster or tearing off the siding? Or am I better off just putting my money into great storm windows and a more efficient heating system? Thanks!
Jen
Green Talk says
Gary, any comments? Can she blow it in? Does she need to with the thermal mass of lathe and plaster? Anna
Z & B says
Gary, we’re located in Chicago and live in a brownstone 1930’s recently rehabbed 3-flat. Unfortunately the builder did little to nothing with regards to insulation – either between floors or to exterior walls, crawl spaces etc. We too have plaster walls but need to find a solution that can be blown or poured in. What would you suggest please for our place? It’s freezing (even the pipes have frozen) and our furnace is struggling to keep it at 56f! Many thanks in advance for your wise counsel.
Bill Bloomquist says
After reading all these posts and a hundred or so articles about the safety, durability, and energy savings from using Icynene plus seeing all the environmental certifications about it AND the international acceptance of Icynene as one of the very best foam products ever, I am intrigued that no one has brought up the probability of improper installation, or pre-existing conditions.
Home builders, commercial clients, homeowners by the thousands environmental experts, testing labs, all over the world are promoting this as the all round safest product of its kind.
Are they all 100% wrong or deluded?
Don Atkinson says
No they are neither wrong nor deluded.
Icynene will work just fine if properly installed in a proper situation. It is not the right answer for every job and there are situations where it is not the best and might even be the worst choice.
Done right it is great, done wrong it is trouble.
Taylor says
Interesting site with a lot of good info.
I do not see anyone mention P2000.
Go to the site P2insulation.com for information about what I believe is the best insulation available today.
The biggest heat loss factor with insulation after the air infiltration has been stopped is radiant heat loss.
Spray foams do not address this at all.
Would gladly field questions about this product that I discovered about 1 month ago. I’m building a timber frame house in Mass. and was looking for alternatives to foam core panels ( $$$ ). P2000 showed up on a blog, I did a lot of research, and found what looks like the answer to what a great insulation product should do.
Green Talk says
Taylor, can you tell us about P2 insulation. Anna
Taylor says
Anna, P2000 is an EPS core, with facings of reflective mylar on both sides. It comes in rolls 4′ wide x 100′ long ( 1/4″, 3/8″, 1/2″ ), and sheets 4′ x 8′ x 3/8″, 1/2″, 5/8″, 3/4″, 1″, 1 1/2″, 2″, and 3″.
The company uses proprietary methods of manufacturing.
The posted R values are the same as EPS, but in March the new tested R values will be published and promise to be the industry leader.
All the testimonials I have read show P2000 to be the best in all categories.
It does what insulation is suppose to do.
1. stop air infiltration.
2. it’s a vapor barrier.
3. it stops thermal bridging, which has not been addressed on this post. 2x framing in walls accounts for approx. 25% of wall space. All spray foam insulations cannot insulate the studs, headers, plates, jacks, cripples, partition backers, or corner blocks. The R value of these framing members is about R 3.
That means that with spray foams, 25% of your walls are still a R 3.
4. it is a radiant blocker. This is perhaps the biggest advantage of this product. Radiant heat loss is calculated to be between 50% – 80% of the total heat loss in buildings and homes.
P2000 stops 90% of this heat loss in the walls and ceilings using the reflective mylar coatings with the EPS core.
5. it is a radon barrier.
With any new innovation there will be adjustments to deal with regarding installation, but the way I see it is to do it right the first time and be done with it…
I have been in the building trade for 30 yrs., and have had a keen interest in innovative products in our industry.
Unfortunately, house construction has lagged WAY BEHIND other industries in terms of technology and cutting edge innovation and design.
If you are interested in the leading edge of home construction, I would urge you to get Tedd Benson’s latest book on the building they do. He owns a timberframe company in NH. and constructs what are probably the finest homes in North America regarding efficiency and design.
His latest book is titled ” Timberframe “.
Thanks for your question, and I’ll be happy to address any other questions you may have about P2000. I know this tends to be a subject that takes a lot of study to reach a satisfying and solid conclusion.
Taylor
Green Talk says
Taylor, how does it compare in price to fiberglass and foam. How do you install this foam? I have heard that termites like EPS. Does this EPS have borate in it? Anna
Taylor says
Anna, First the borate. The answer is no. EPS that is exposed to soil may use borate to kill termites, but this has a mylar wrap that prevents the EPS from coming in contact with the soil.
Cost per sq. ft. ranges from .52 – 1.65, depending on thickness. When the official
R values get posted next month, this promises to open a lot of eyes.
I’ll keep you posted, and keep the questions coming if you like.
Thanks,
Taylor
Dave says
This is an interesting website.
I am a builder and the installer and other websites says that Icynene is the best open cell foam out there. It is better than closed sell because closed cell does allow air into the home. Closed cell foam fits between the studs like a pillow.
If it is installed correctly, it is better than closed cell foam. Icynene is not a food source for mold. It has been professional tested to see if it is a food source. It will not support any bacterial or fungal growth. It has no food value for insects or rodents. If there is a water problem in the home, you must fix the problem for any type of insulation.
Fiberglass is used in your furnace to filter air and the same thing happens in the wall with fiberglass insulation. The warm air goes up the inside just under the drywall and the cold air drops on the outside. You have to stop the air from moving (looping) and I would suggest Cellulose as the best answer. Air will not move in Cellulose. Try to burn cellulose and it will not burn. Try to burn fiberglass and it will melt.
I try to build affordable Energy Star homes in the $100 – $110 per square foot range. I use 15″ in the attic which is a R-52 with a 3 1/2″ raised energy heal, 3 1/2″ in the exterior wall and that is a R-12.95, caulk the plate line with drywall glue/caulk to stop the air between the bottom plate and OSB floor and insulate the box sill with 5″ of Icynene which is R-18. I finish up by priming the walls and ceiling drywall with vapor retarder paint.
The last home tested in at less than 70% to code. It met the Builders Challenge and for more information check out Dept. of Energy . . . DOE website: http://www1.eere.energy.gov/buildings/challenge/
I will check back and see how the debate goes on open or closed cell foam. I still think that Icynene is the best but you need to control any water leak in your home.
Green Talk says
Dave, I thought closed cell did not let air infiltration into your home. Have you used the new Icynene with castor bean oil in it yet? See any difference? Anna
Dave says
Anna, Closed cell is fixed and will not move, that is what I have been told anyway. Open cell is like a pillow, it will move with the framed of the home. I do not know what is in the Icynene … I build homes and try to listen to what people tell me. I check out a few websites about insulation and try to learn more about how to save energy. I do know that if you control the air movement, you will control the energy requirement.
Green Talk says
Dave, keep up the great work on saving energy. Hopefully all builders in the future will think this way too.
imt says
I am in the process of taking advatange of NJ’s Energy Star program where you have a certified BSI contractor come in and do the blower door testing, IR camera etc. I had this done the other day and will be awaiting the report. In our discussions open cell foam had come up for sealing the attic and outside walls. I have been an avid reader of JLC, Fine Homebuilding & Building Science online so I have read alot about spray foam. In my attic I have my AC system. So to turn this into conditioned space should technically be a real benefit. I will also be doing a fair amount of remodeling where the walls could be open for about 1/2 of the living space. This would also give access to the attic above the lower part of the house (I have a split level).
However, correct me if I am wrong, but I thought only closed cell foam should be usind for an unvented attic. While open cell with restrict air movement, it still allows moisture to pass through. Also, in NJ, which I think is a zone 5 climate, you must have a vapor barrier installed on the inside. I think unless you have a certain depth of rigid foam installed on the outside. Thus, I cannot see how open cell would work here.
If foam was to be used in the attic, it would be a retrofit. One thing I have heard is that when retrofitting wth foam (Not sure if this is both an open & closed cell issue) that you can have an odor that will not go away since there is no where for the product to off gas. I have heard of needing fan’s etc to try and vent out the space but many times this is insufficient. IfFoam was the best route to take, I could have them inisitally leave the gabel vents in place, so that it could be vented and then in a week seal those off. Thoughts.
The outside sheathing on the exterior walls are celotex (There is plywood around some of the newer windows I have put in and resheathed. I plan to re-side the house at some point but not in the budget as of yet. When I do I would have them rip off the old siding and then tyvek. So…… I am not sure what is the best approach to take. What would be recommended in my climate for the exterior walls as well as the attic. I want to be armed with more info when I receive the recommendations from the testing is a couple of weeks.
Green Talk says
IMT, I am in NJ. My 2nd floor is ceiling has the foam not my attic. I elected not to insulate my ceiling rafters with foam although my geothermal and ducts are up in the attic. I do agree that a condition space for duct work and for your air handler is preferred. After the fact, we built a conditioned space for the geos and will be spraying the Closet as well as the ducts.
One of the reasons why I did not elect to spray the attic was aging the roof. Where they did spray is the last place that dries out. When I interviewed BASF, who creates closed cell insulation, they told me that my roof would be okay; however, they noted that closed cell can not be left exposed. See my article, http://www.green-talk.com/2009.....s-comfort/. I am wondering if this is true for open cell as well.
My understanding when the attic is sprayed, they spray the vents as well.
I do not have a vapor barrier in my walls other than the icynene. Let me know what you think about your energy report. My house is an energy star house and all they did was a blower door. They did not even tell me if there were any leaks except I passed the test to become an energy star house. I hope I answered your questions. If not, let me know. Anna
IMT says
Hi Anna,
I just got my report back just now. From the blower door test, my air leakage, on my 1969 split level home, was determined to be 4350 cfm50. It states that standards indicate that the building air tightness limit is 1748 cfm50. thus I am 149% greater than the limit.
What is proposed is to spray my attic rafters with open cell foam, product is not Icynene. I am awaiting info with the foam info. It is to be sprayed 6″ on the rafters as well as the gable walls.
I had brought up that everything I have read has been to put closed cell foam on the rafters vs. open cell. Maybe I should pose the question to BASF since they make both as you said. I have ridge vents that would have to be sealed and an attic fan that would need to be removed in the upper attic. I also have read many people who have retrofitted foam (Both open and closed) that there is an odor that lingers, since the air is trapped in the attic with no airflow to dissipate. I did bring up the idea of leaving the gable vents in place to let the attic air out and then seal it up in a week or so once its fully aired out. I am pretty sure both open cel and closed cel foam has to be covered with wither drywall or a spray coating for fire resistance if the attic is used for storage or has mechanical equip.
Just want to make sure that open cell is right for this application.
Green Talk says
IMT, that’s a good idea to call BASF’s tech department and talk to them about closed and open. Is your installer going to spray something to fireproof the foam? Anna
imt says
I will try and give him a call later. I have also been looking into a product called air-Krete. Been around for a while. Fireproof, so not an issue in the attic. Should lower insurance bills :). Cement based. Spoke with the Ceo just now. Sounds very interesting. No mold growth and in fact the akaline nature of the product kills any mold. Non toxic. They are also going to be offering the bility to add a very low toxicity fungicide (Like used in caulk, etc) as an additional layer of protection withing the foam itself. Not expanding like Icynene or other spray foams. More like shaving cream consistency when its dispensed and thus the install is much slower but the product is more fluid and takes approx 24 hrs to cure. I will also see what the cost of this would be. They do retrofit this as well as looks interesting from that perspective.
Green Talk says
IMt, this monday I will airing a podcast on Air Krete. I interviewed one of their installers. Anna
imt says
One. How do I get the podcast. Two. Where is this installer? in NJ? I got a name from Air Kerete but wondering about others in NJ as well. This product realy sounds interesting and I may go this route. I have to get some pricing to see though.
Green Talk says
I post it on the site along with a short summary of what is in the podcast. I will probably post it on Monday.
Yes, the installer is in NJ. Don’t remember his name right now. The product is pretty interesting. Note, you will have to install drywall to contain it. It isn’t foam. Anna
John says
I agree icynene is not to be used on a slate roof but i disagree that icynene will wick water. Have been using both product for different applications for many years and each has their merit. Closed or open are both great products if used correctly by an approved installer
IMT says
It is a foam per se. Not a open cell or closed cell spray type foam. It is air bubbles that are encapulasted in the magnesium oxide (cement). It looks like regular white shaving cream (not the gel stuf) when dispensed. Has the same type of consistency. It flows out slow and is more fluid so it runs into all of the gaps and crevices. There are video’s on you tube as well as there site. Where foam cures right away, this take approx 24 hrs to fully cure. Thus ,its perfect for a retrofit. They install from the exterior and the walls contain the foam. On the viseo’s I saw online for new construction, they install tyvek or mesh on the insterior side of the wall to hold the foam in place. the spray it in and fill the cavities and then smooth it out and then let it cure for the 24hrs. When I spoke with the CEO he told me that what they recomend is to install the sheetrock on the walls and cut back a foot off the top board. They then fill the cavity from the top and put tyvef on the top foot to keep the foam held back. Not sure if you spoke with Fabio at Alberti in Union I believe, but I was told he kind of pioneered this install technique. My question was how do local inspectors allow this since you have an insualtion inspection prior to sheetrock install. He said that the local inspectors where he works have approved and allow him to use thermal scan showing the install of insulation after the fact. My concern her would be that you now have this long continuous but joint that has to be taped all around the entire room. Usually you offset the joints to prevent cracking and the work involved to smooth a huge long but joint that goeas around each and every room will be a large amount of labor I would think. I am going to tray and call them later or maybe Mon. Might want to listen to your podcast first. Personally I would rather do the mesh or tyvek approach so one can see the fill and make the sheetrock install easier.
I did ask about insualting the roof deck. He said it could be done but the CEO is still a believe in a cold roof approach vs. spraying the underside of the entire roof deck. More so when it comes to an asphalt roof over Steel or tile, which would not be affected by any increase in heat in the summer months. He advised installing baffles in the rafter bays up to the ridge vent. Thus keeping the soffit vents. You would then install tykek over the rafter to hold the product in place. They would slit the tyvek every few feet to install the foam. Thus the foam encompases the the cavity and the air baffles so you still have a cold roof that can be ventalated in the summer. The openings in the tyvek will help the product cure faster since the depth is much greater than would be needed in a 2×4 wall. The rafters would most likely need to be furred out to have the adequate R-value. Also lath strips would be installed across the rafter bays to securely hold the tyvek in place, if you wanted to go this route. I was since I have my A/C air handler and duct work in the attic.
Green Talk says
IMT, I spoke to Fabio. I agree with the CEO about cold roofs. Most foam people don’t agree. One part of my roof has the icynene without the baffles and it is the last part of the roof to dry. When I asked the installer about the baffles vs no baffles, he told me they don’t install the baffles.
Anna
IMT says
You are saying that the Icynene installer said that they don’t install the baffles or Fabio said that?
Also, when you say that there is one part of the roof that has Icynene without the baffles and it is the last to dry do you mean from rain or snow in the winter? If you mean snow, then this isn’t a bad thing since the temp of the roof deck is cold thus no heat escaping in the attic to warm this part of the roof.
Green Talk says
Icynene installer told me this. It is the last to dry when it rains. My attic so cold in the winter that you could freeze meat up there. No heat escaping from the 2nd floor to the attic. We have foam between the attic floor and the 2nd floor ceiling as well as air tight recess cans. Anna
IMT says
Hmmmm. That is interesting. This makes me question the foam approach on the roof rafters. Possibly even the Air-Krete route, if I went that way. Even in that situation you would only have the baffles down the center of the joist bay so in theory only this part will dry and the rest on eithe side of the joists will take longer to dry. I imagine having stripes down each rafter bay that are dry and the rest wet :).
I have to go back and re-visit the attic. Maybe I can frame out and box in the equipment and ductwork so its technically in conditioned space and then either do Icynene, like you did in the floor joists and the outside of this built-in area. Then the area on the outside of this conditioned space is still vented. Sort of the best of both worlds. After I have read years back about the ineffectiveness of fiberglass and air movement, it never made sense to me why fiberglass would then be used in an attic by itself when using a cold roof “vented”. Maybe if it was covered in Tyvek, as an air barrier it would peform much better.
I do have one question, you mention that they sprayed the floor in most of your attic. I assume that they went all the way out and sprayed over the top plate around the perimeter when filling the joist bays. did they not put baffles here to allow the roof to breathe with soffit vents? Or do you not have any soffit vents? I would assume you still would have them with a ridge vent in this senario.
IMT says
I didn’t see the podcast posted yet for air krete. Do you know when it will be up.
hvacrsteve says
I have had two homes with Icynene, the first, I had a great installer, he new his product and how to install it.
The second has been a nightmare, my home is cold and drafty and poorly insulated.
The installer out of Mechanicsville, Va is a complete idiot.
My bills are three times what my old home was.
I have contacted Icynene, their corporate office on multiple occassions, I have yet to get one reply!
I have talked with Susan Preston in customer service and all I get is lip service!
I will never use Icynene again, no matter the price or anything else!
Let them my homes lack of savings on their website!
It is going to cost me about 50K to repair the damage and properly insualte my home with closed cell foam!
Green Talk says
hvacsteve, sorry to hear this. Did you contact the better business bureau? What did your installer say about the drafts? Anna
Gary L Maedl says
Jen- Sorry I missed your question. Hope that this information helps you.
As I stated in an earlier response, rigid polyurethane is great for insulating old houses. However, it must be sprayed on the inside of the outer wall sheathing. Unfortunately, you have to remove the lathe and plaster in order to do this easily.
There are expert foam insulation guys that can get the low expansion type of rigid urethane inside of the wall if they have a 6″ wide access point for each wall cavity. But it is very tricky to make sure that the foam gets all the way to the bottom/top of the wall and to not let the expansion of the foam push the walls apart.
The other problem with this approach is that rigid polyurethane should not cover wiring, especially old type wiring. The wires can easily overheat (the insulation prevents the wire from cooling itself) and cause a fire. For this reason, we always do the wiring AFTER the urethane insulation has been installed.
You might be best to use a blown in chopped fiberglas. It is a pretty good insulator if installed properly, and is certainly better than no insulation.
Also remember that approximately 70% of your heat loss is through the attic/roof. So insulating this area is the most important.
solarglobalgreen says
Sounds like sort of a mixed bag. I think I will take a wait and see approach with this product.
daveP says
I have a 1930’s 2 story brick tudor with clay tile roof in west suburban chicago. Originally built with NO attic ventalation at all. I had to remove the rock wool in the attic after it was contaminated by squirrels. After 70+ years the roof felt-paper under the 1st course of clay tiles disentegrated and there we some 1″ to 1.5″ gaps between fascia boards and edge of roof deck boards – behind the gutters. Squirrels entered the attic through these now exposed gaps as did alot of moisture.
Now I have roof repaired with ice & water shield & copper flasings – these gaps are mostly sealed up now. In dark attic a few rays of day-light still visible here and there so a few gaps remain. Foam will help seal thses up if sprayed down into the eave cribs. HVAC ducts run from basement to attic “octopus” that splits vents to each bedroom.
There is no way to fit proper eave vents because of the eave configuration. It will be possible to install a small gable vent near the west facing peak and a smaller intake opeinhg across the attic on the east side about 8′ lower to get some air movement, albeit minimal.
Now the question : can I — should I spray down Icynene on the attic floor? Installers says 5.5″ average and 3+ inches on the ductwork. He says I have to have some ventillation in the attic for this Open cell application – but of course will not say that the venting I described will be enough or not.
Close cell is out of the question -more than twice the cost of open cell which is 50% more than loose fill.
Any thoughts?
Green Talk says
Dave P, have you considered blowing in insulation in your second floor ceiling? Do you have any recessed lighting in the second floor? My insulation is in my ceiling not my attic. That is funny that the installer says you have to have ventilation. They told me just the opposite. Call Icynene’s tech department and ask them.
Gary, if you are there, any thoughts? Anna
KK says
Don’t have time to read all these comments here but will put in my two cents after having icynene in my house for over 10 years.
Bottom Line: It all depends on the installer.
Personally I love the product. It has lowered my heating and cooling and I pay 1/4 what by brother pays on a house with twice the square footage.
NOTE ON INSTALLER: Installer tried to create firestop using icynene… spraying directly on the pipes. Said “I do this all the time”. I forced builder to pull it all off and put in regular firestop to code. Builder only pulled part of the product off and installed firestop so I couldn’t see that he left large chunks still sprayed to fireplace insulated chimney. Result… Back of house burnt after 3 months of living in the house. THIS STUFF IS NOT FIREPROOF.
I love the product… hate the installer.
Mark S. Reed Sr. says
Hello everyone,
I have reviewed all of your posts and would like to add one of my own…
2009 was a life changing year for many people and businesses… For me it was the first time in my 23 years of operating a residential remodeling company performing all phases of building and remodeling— that I felt the pich of the economy…
One day my son and I got to talking and he shared with me some information about these classes “green-building classes” held at our area community college by the Building Performance Institute… I innitially thought what can these people possibly teach me about building a quality “green” home— I’ll paint it any color you like… As you can see I was very reluctant at first, but as time went on— the phone continued not to ring… As time went on I started to ask my self what is going on around me… My son said, the “green movement” dad… And we better get with it or we are going to be left behind…
Back in June of 2009 two of my sons and I attended our first class from The building Performance Institute, called The Building Analist.. And I have to tell you— it was a humbling experience for me… For years I always thought I was doing the best for my customer— well this first class tought me what my customers werent telling me they wanted from me- hence, I believe that is a big reason why the phone slowed down- my customers had become smarter than I the professional (if they would have only talked to me- I would have listened sooner)… A few months later we would continue to attend the BPI schooling completing The Building Envelope training.
Since the BPI schooling we have added Thernal Imaging, Blower Door Testing, Home Energy Assessments, Insulation & Air Sealing Techniques with AIR KRETE Greensulation to our NEW core services, and we are busy than ever before (old and new customers).
Prior to becoming an Air Krete installer we did our homework— innitially the Icynene spray foam was going to be our product for perform insulation and air sealing- that is until we found about Air Krete… Air Krete is an amazing product and I feel very priveledge and honored to be offering this product to my customers.
BPI and AIR KRETE have regnerated myself, my sons, and my employees… I am proud to say that we are focussed on being a more environmentally conscious company, and all of us are hard at work alligning our company with other green services and techniques to be the best company for my customers…
If anyone has any questions on the product, I would be more than glad to answer your questions…
Thank you Anna and all the folks supporting Green Talk, it is a fabulous website that I parton often.
God bless you all, and best of luck with your green building projects.
Mark
joe says
Looking to put R-60 in my attic, which is better
blown in cellouse or blown in fiberglass
I have read so much its confusing looking for some expert advise
Green Talk says
Joe, i am not an expert but I can’t be around fiberglass. It makes me cough uncontrollably. Also, your blown in fiberglass may contain formaldehyde. Ask.
Also, ask the company who makes the cellulose if you can blown in cellulose without it needing it to be covered. For example, closed cell insulation need a fire protection barrier so it shouldn’t be left open in an attic.
Have you considered Ultra-touch cotton insulation? They have a R-30 variety so you can do it yourself. I have it and it is like a big blue pillow. No itch or formaldehyde.
Do you have recessed lights in your second floor? You can’t blow insulation on top of them in your attic.
Anna
Brandon Jankord says
Hi, I just read this article and wanted to point out one thing that is wrong with it. It is the part where Icynene is a petroleum base product, which is not true. I have been in the Icynene business for almost 10 years and i know for a fact that it is a water base foam. Petroleum base foams have a water absorbtion issue and it also gives off gases. Icynene is the only foam around that doesn’t have a problem with any of those, plus we give a lifetime warranty that it won’t ever have those problems. Thank s for letting me clear those issues up.
Gary L Maedl says
Dear Mr. Jankord,
Icynene IS a petroleum based product. Read the following taken directly from the Icynene website:
“What is the Composition of Icynene®?
Icynene® is a water-blown half pound plastic foam insulation that contains no environmentally harmful blowing agents like HFCs, HCFCs or HFAs. Organic chemical compounds from petroleum extract are the main source of its ingredients. VOC emission testing by Saskatchewan Research Council has revealed that there were no VOC emissions after 30 days.”
You can check this out yourself at: http://www.icynene.com/faqs/
You may have been in the Icynene business for almost 10 years, but this does not mean you know everything about this stuff.
I have been using foam insulations since 1975 and have a degree in mechananical engineering with a minor in polymer chemistry, and I don’t pretend to know everything about Icynene.
As said earlier in this blog, it is all about the installation.
Green Talk says
Gary, you beat me to the punch. Icynene does have a new product, ICYNENE LD-R-50™, that the Company claims has about a seven percent castor oil base, which means that a certain percentage of the foam is not produced by using petroleum products. Anna
Gary L Maedl says
Anna,
By chemical definition, the “-ene” ending on the name Icynene typically means that it is a carbohydron with at least one double bond in the molecule. Although these chemicals can be created in the lab using other base elements, they are typically derived from petroleum for sake of ease and cost.
This is not to say that petroleum based products are bad. Quite the contrary. Without petroleum, we would not have any of our modern plastics, for example.
However, from a chemical viewpoint, there is little difference between castor oil and petroleum. They and all oils have an organic as their foundation. For castor oil, it is the castor bean. For petroleum, it is ancient plant life.
Solar Global Green says
I assume that this product is eligible for the 30% tax credit from the federal government making it that much more attractive for someone looking to lower their energy bill.
Green Talk says
Solar Global, good point. I would think that the rebate would apply but everyone should check the rebate section. Anna
IMT says
Yes it would. Also its 30% is capped at $1500.
Anna,
above you made a comment that your Icynene is installed in the second floor ceiling and not the attic. Isn’t your second floor ceiling the floor of the attic? or did you mean that it is installed on the second floor ceiling in the attic not on the rafters of the attic?
Also, I am unclear about the comment to Joe in regard to not installing blown insulation over the recessed lights. Doesn’t it depend on if he has IC rated cans or not? IC recessed lights are meant to be burried in insulation.
Green Talk says
IMT, you are correct on both account. The Icynene is blown in between the second floor ceiling and the floor of the attic. And yes, you need to have IC recessed lights to have blown insulation covering them. I have IC cans. Many people do not have IC rated cans. In my last houses, I did not. Thanks for asking for clarification. Anna
Designer Radiators says
I agree. We have used this product extensively throughout our house during renovations. In fact I suggested that we purchase shares in the company as we had bought so much and regularly at that. It became a household joke! At certain stages before painting and finishing the house look like it was actually built with the foam. Fantastic product.
Christina says
I am currently working on a 4th floor condo project. It is technically attic space converted into a home. The roof is my ceiling. I would like to try icynene but in conjuntion with low voltage ic-cans. Low voltage IC rated cans have there own transformer so they typically run hotter because of this I was concerned they may be tooo airtight with foam insulation. Juno(a recessed lighting manufacturer) said that the ic-cans were not rated for this type of insulation. Would appreciate any help on this one. I can’t seem to get a straight answer.
Green Talk says
Christina, have you looked at Cree’s 4 inch LED recessed light or Progress’s LED Recessed light? I don’t know if they are IC rated. You would have to talk to the manufacturers (Cree and Progress.) One thing I noticed is when I did another blower door lately, the cans showed air leaks since the foam did not get into all the crannies and wires around the lights. You may need to inspect after they are done and it cures.
Whatever you decide, I would check with the manufacturer of the light.
Another suggestion is a ceiling light or chandelier. Given what I learned about my own leaking IC cans, I think I would not put recessed up again on the second floor. See also this thread: http://www.inspectionnews.net/.....hting.html. Anna
Readers?
Gary L Maedl says
Dear Christina,
PLEASE do not insulate with any type of foam directly around IC cans in your ceiling! You are asking for trouble from overheating which could possibly start a fire.
Although this type of recessed light is rated for direct contact with insulation (IC = Insulation Contact rated), the UL rating tests are done for “loose” types of insulations that can breathe easily (i.e.- fiberglas, etc.) and not intended for foams which are pretty much air tight.
Recessed lights (at least the better ones) should have a high temperature “cut out” safety device which kills the power to the light if the housing gets too hot. This results in the “blinking light” syndrome. But if this safety device fails, you could get overheating which might cause a fire.
I had a house I built a number of years ago where the insulation contractor blew cellulose insulation directly against and over the top of recessed Halo® IC-rated lights in the 2nd floor ceiling. One of the lights failed during the first week and the roof caught on fire. Luckily we caught it pretty quickly and the damage was minor.
At the time, the solution was to put a fire rated “cone” over the top of each recessed can that gave about a 2″ air space all the way around the light and kept the insulation away from direct contact with the light housing, but still stopped the heat loss and air leakage. But I don’t know what the latest codes are on this type of installation.
In addition to strict adherence to the manufacturer’s instructions, you could also contact your local building inspection or fire marshal and they could advise you with the latest information.
Chip says
I am a homeowner re-doing my garage. So what is better? Icynene, BASF’s COMFORT FOAM® Insulation and Air Barrier, AIR KRETE, High R-Value 38 traditional fiberglass insulation? I am interested in temperature stability (very important) and the best sound proof (less important) for a garage project. Whirly bird turbine to vent heat in the summer, but hot air escapes in the winter. I am so confused. My roofer tells me to vent (sell me a serivice) and the insulator tells me BASF one or two inch spray insulation without ventilation.
IMT says
Gary,
Can’t you use these for the recessed lights.
http://www.tenmatusa.com/lightcovers.html
http://www.tenmatusa.com/draftcovers.html
Gary L Maedl says
IMT,
EXACTLY!! Thanks for finding them!
Gary
Gary L Maedl says
Chip,
What do you plan to do in this garage? Are you converting it to living space, or just want to have a heated garage? The insulation criteria changes with the area’s usage.
Gary
UPVC Windows says
Icenene is a wonder product. I can actually vouch for this as I have used it extensively in and around my own home. You can use it to retro insulate. I have used it in and around newly replaced window frames and it actually helps to bulk up some space.
Area Rugs says
My partner and I used spray foam insulation any where and everywhere through out our home renovation and yes without question we are impressed with the improvements.
Auto Transport says
I’m not yet acquainted with this Icynene innovation since I don’t used or install insulation products in our house though. Anyway how can we be sure that this product has no downside or is harmless?
Anna@Green Talk says
Auto, you can never be too sure it there is no environmental harm. It is a balancing act. The downside of Icynene is that it is made with mostly a petroleum based product. The upside is it insulates your house better than fiberglass. Anna
Flooring Arlington VA says
I was totally sold on this product until I found out it was petroleum-based. Frankly, to me, that is a deal-breaker. I understand insulation is an important for overall energy-savings but using a petroleum product as an energy-conscious alternative just seems like a zero-sum alternative.
Anna@Green Talk says
Flooring, check out my Airkrete Insulation. You might like this better. See http://www.green-talk.com/2010.....rgy-bills/. Anna
Refurbishment London says
Hi Joe,
I am a London builder, and have worked extensively with various types of insulation, but all too often we get stuck with either Kingspan or Celotex specifed by the architect of the development we are working on. And yes, you guessed it, the primarily reason for this is… cost.
The cost is a massive hindrance when it comes to construction, (especially these days), and that goes for both commercial and residential developments. As long as they hit the correct U-Value, (your R-Value), and it is cheap, the customer don’t really care. That is the unfortunate truth about the world we live in.
I salute you for giving Icynene Insulation ago, and being willing to pay the extra dollars for it.
Martin, Preisler Construction Ltd.
London
Conservatory Roof says
Some great advice here. These days its all about the U value…see here for a bit more info about U value.
Curtis says
I own and operate four radio stations, and recently constructed new studios for them.
At the last minute, I was talked into using Icynene instead of the fiberglass I was budgeting for. It was much more expensive (almost 3 times more) but I was impressed by the demonstration and soundproofing claims.
The soundproofing claims turned out to be absolutely true. Even the indoor acoustics of the rooms were affected.
During our first weeks of operation in the new studios, the gas company came to visit, telling me they had to replace the new gas meter already. The next week, they came again, this time, asking if they could activate our furnace manually, to check the meter. I asked why, and they told me the meter was hardly measuring any gas being used.
Turns out, simply the electronics in the sound studios were enough to heat the building, and even in the cooler temperatures, the air conditioning will sometimes activate to bring the temperature down.
I would highly recommend this product for the above reasons. I have no doubt it has already paid for itself.
I’m planning on using it in a vacation cabin. I only hesitate because of the high cost in a construction that wouldn’t be occupied consistently.
If you have the extra money in your budget for it, do it. You won’t be disappointed.
Anna@Green Talk says
Curtis, that is great information about the insulation’s sound proofing. Anna
Debra Guevara says
The thing that I miss most is layout tools comparable to what I get in java, flex or even good old Delphi (border layout, grid layout, flow layout, …). I get that CSS is meant to style single-column documents, and for that it is great, but the reality is that web 2.0 is not built out of single-column documents.
Foam Core Panels says
I see you’re recommending the Icyene Insulation system. Can you tell me how the price may compare to a standard foam core panel? Is the Icyene system cheaper because you’re just buying the foam material and supplying the labor yourself?
Anna@Green Talk says
You need a professional to install. Icynene is expensive, but the price differs depending on location. I am sure it costs more than foam board. Anna
Remortgage says
Even if you remortgaged to pay for this type of insulation the amount of money you would save from lower heating bills in the long run would more than cover it.
Mark Richards says
I’m knew to Icynene but I’ve heard a bit about its advantages and disadvantages. Your article has covered many of the benefits of using Icynene, but I have seen cases online where the family using Icynene found that it is not water repellant at all. Worst still, in that case, the owners found mold growing where they injected the Icynene. It might be an isolated case though.
Anna@Green Talk says
Mark,
I have heard this too. I think if you have an ongoing leak, the open cell will eventually soak it up, Have you had an experience with mold removal with foam insulation? Anna
Laura Vaughn says
Anna, we are looking to have foam insulation sprayed onto the ceiling of our attic and also on the ceiling of our basement (which is mostly dirt covered in black plastic). We were all set to go with FOAMTEC, but due to paperwork issues, our HomeSeal Atlanta rep now wants to go with another installer who uses Icynene. I’ve been reading your blog and I’m seeing a lot about water leakage, black mold and extreme outgassing. Granted I have not read through all of your blogs and was wondering if Icynene has improved (since this blog began in Sept. 2007) and is now an acceptable product to use (with ICYNENE LD-R-50™ in your reply to Gary in Feb. 2010)? Do you have any comments on FOAMTEC? Also, can you recommend a reliable, proven installer of Icylene and/or FOAMTEC in our area? I appreciate your help and consideration. Thanks.
Gary L Maedl says
Hi Laura,
ICYNENE has a specific chemical formula. “Improvements” to it cannot change the fact that it is an open cell foam and it absorbs water. High-density polyurethane (closed cell) foam will not absorb water. This is the type of foam you really want for the application that you are considering. It is more expensive, but well worth it; both in insulation value and water proof properties.
Anna@Green Talk says
Gary, what do you think about Aircrete, which is open cell but made of Mag Oxide cement? I don’t know Foamtec at all. I have had Icycnene for seven years and haven’t found it to be a problem. I don’t have water leaks. I didn’t find it to offgas when they were installing it but they do show up in hazard suits. Did you call EarthCraft (http://earthcraft.org/) for a recommendation.
One thing I will say about all of the insulation, they don’t stop air infiltration where the studs meet. Wood has very little R value. We did silicone where 2 studs met. Gary, how do you feel about gaskets in those areas?
Gary L Maedl says
Hi Anna,
I don’t know anything about Magnesium Oxide cement. My experience (and schooling) is in organic plastics. I don’t know Foamtec, either, and Googling it did not really help. Aircrete gets its insulation value from trapping air bubbles in the cement matrix.
With Iceynene, the installation is everything. If it is installed correctly and in the proper location for the correct application, it is fine. However, for areas where there is high water vapor (humidity), it is going to absorb water no matter what. So this has to be taken into account.
With respect to “where the studs meet”, I assume you are talking about double studs at window jambs, corners, etc. Yes, this an issue IF the framer doesn’t nail the studs together tightly and doesn’t take care when seaming the sheathing. Wood is not a bad insulator; it is about R1.4 per inch per pine.
But gaskets would be a lot more expensive (high labor) than putting a well sealed layer of Tyvek on the exterior of the sheathing. I also like the new systems where they tape seal all seams on the sheathing. Done properly, this should stop the air infiltration.
But all of this applies to new construction. For existing buildings, sealing air leaks with silicone works, but can deteriorate over time. I’ve found that Gorilla Glue works well as it expands like crazy and fills all the little cracks. Then you can shave off the excess. (This is urethane, by the way.)
Laura Vaughn says
Hey Gary, thanks to you and Anna for your quick response… is Foamsulate 50 (open cell for attic ceiling) and Foamsulate 210 (closed cell for basement ceiling) good examples of a high-density polyurethane foam product? If not, what would you suggest?
Gary L Maedl says
Foamsulate 50 is not high-density polyurethane. It is low density and open cell (will absorb water). Foamsulate 210 is a medium-density polyurethane, closed cell.
(Refer: http://www.icc-es.org/reports/.....R-3081.pdf )
If it were my house, I would use the Foamsulate 210 and not the Foamsulate 50.
Laura Vaughn says
Gary, if an installer sprays a high or medium density closed cell foam in my attic ceiling, what happens if the roof gets a leak… how would we know?
Gary L Maedl says
Hi Laura,
Hmmm… That’s an interesting question. My first response would be that the leak would not get past the foam. But that leaves the possibility that the roof deck itself could rot and lead to a major roof replacement job; although this would take many years.
I have to say that the only answer I have is to put on the very best shingles you can, and make sure that the eaves and valleys are very well constructed (lots of Grace Watershield and aluminum flashing). Leaks in the middle of a roof are unusual unless it has been damaged by something. The eaves and valleys are usually the problem and should be inspected periodically by an experienced roofer.
Jonathan says
Laura,
If a closed cell foam is used in the attic ceiling and you get a leak there is no where for the water to go. people use the foam to keep water out but you are right to worry, if you have pockets where the water can rest and a good amount of water your timber will eventually rot. I would personally use something like Icynene so if you spring a leak it is visible where it is as the water will pass through. You can remove the section of insulation, repair the leak and patch over. Its alot cheaper than re roofing.
Anton L says
I am very confused now.
I am about to start a major renovation in my 1920’s house with slate roof in Massachusetts. The contractor recommends Icenyne for roof insulation, in an area that will have a cathedral ceiling. Does any one here have a recommendation as to the best insulation that would also allow me to detect a potential roof leak before it could cause any major damage?
Gary has consistently disavowed Icenyne for attic/roof insulation in favor of closed cell polyurethane for five years in this blog (yes, I read all of it). In his latest reply (2012) he hesitates on closed cell while considering roof leakage, because of the possibility of undetected major damage to the timber in the roof deck.
Jonathan replies that Icenyne would be better in this case because the open cell would let water pass through and a leak would be detected before major damage occurs.
However, Gary’s major concern has always been that open cell Icenyne would trap water like a sponge. That cannot be good for a leaking roof either!
Which one should I choose, open cell or close cell? Is there another, better, alternative to either Icenyne or polyurethane for my application?
Gary L Maedl says
Hi Anton,
I have NO hesitation using rigid polyurethane for insulating a roof system. It is the only way that I build.
Jonathan’s statement that the water will pass through the Icynene is misleading. It will be absorbed by the Icynene just like a sponge and, because it will become saturated, will also wick through and show on the inside of the ceiling.
However, at this point, your entire insulation system (Icynene in that section) will be full of water. It is not passing through harmlessly. It would be wicking the water and collecting it. (To see what I mean, put a dry sponge into water and watch it expand as it drinks in the water.)
In contrast, rigid polyurethane will not let the water through. So detecting where the leak is coming from on the inside would be difficult. You would have to examine it from the outside to determine where the leak is occurring. But any damage a leak could cause would be minimized, if not prevented, by rigid polyurethane. (They use it on the inside of boat hulls, for example.)
Therefore, the leak would not be causing such major structural damage as with the Icynene. Sure, over a very long time the outer wood substrate may deteriorate from water getting to it. But it will not totally deteriorate as the rigid polyurethane on the inside of that plywood would prevent that.
As for slate roofs, there is no way that I would use Icynene. Slate roofs are open by their very design. They are flat pieces of rock layered over one another in such a way that falling rain cascades over their surface and does not come in. Wind driven rain, however, can be forced up in between the pieces of slate and get past to the substrate surface underneath. (The same goes for Tile roofs.)
Rigid polyurethane applied to the underside of the substrate would waterproof it to a great extent; more than any other kind of insulation could possibly do. As the house was built in the 1920’s, this substrate is probably solid wood boards and not plywood, but I cannot know this for sure. The rigid polyurethane would strengthen the overall roofing system. The water would not be able to get to the timbers underneath.
Gary L Maedl says
Anton,
To make sure the insulation is done correctly, contact Ben at Green Stamp Co. http://greenstampinsulation.com/
Anton L says
Gary, this is great. I never even expected you would reply, and much less such a fast and detailed response. Thank you SO much!!
Gary L Maedl says
Anton,
No problem, my pleasure. That is what Anna and I are here for.
Gary
C Mango says
Anna- Glad I stumbled upon this site, lots of great topics and information here!
Gary- your educated insight into foam insulation products is invaluable. From reading this blog I can tell you are clearly in the closed cell camp. When you speak of “rigid polyurethane” do you mean foam board insulation, or blown in closed cell foam? Also, I’m confused about your comment to Anton about water not being able to get to the roofing timbers. Maybe it couldn’t get to the faces of the timbers, but wouldn’t it be able to get to the top edge?
Thanks,
C Mango
Gary L Maedl says
Hi C Mango,
Please see my reply to Home Insulation below.
Gary
SirWard says
Gary, if an installer sprays a high or medium density closed cell foam in my attic ceiling, what happens if the roof gets a leak…
C Mango says
Hey PC- From reading the entire blog going back several years, I’ve gathered that if it’s open cell water will permeate the foam, if it’s closed cell, water will not permeate anywhere the foam is stuck to. That means if you had a roof leak with closed cell foam, the water would only penetrate (and possibly rot) the roof sheathing, plywood or boards. Also, I would imagine the roof rafters could be affected as their top edge (under the sheathing) is not covered by foam.
I think the bottom line is if you have closed cell foam in your attic, you just need to be very aware of the possibility of roof leaks, and not put it off if you think it needs inspection. And when you re-roof, don’t skimp on the quality of materials or contractor.
Maybe in new construction (or if you’re having the roof sheathing replaced anyway) you can take extra measures to protect the tops of the rafters if you know you are going to be insulating with closed cell. Though the particular material that comes to my mind for that purpose is green, it’s not “green”.
Jonathan says
I have been spraying foam for nearly 3 years and i would not put a closed cell foam in a roof. I have seen many timbers that have been rotted due to this. Its not just leaks you need to worry about as i dont think moisture content of wood has been mentioned once.
Closed cell foams are rigid and provide no movement in the roof structure, all structures need to move if only slightly.
Open cell foam is soft and allows the roof to move.
Open cell foams such as Icynene DO NOT wick water, this is total rubbish, I have done extensive testing and this is not the case.
Closed cell foams although called breathable (8%) so do not allow water to pass through.
Closed cell and open cell each have their own application, neither is better and if used together correctly they work brilliantly.
Closed cell for floors, agricultural buildings, walls, tanking etc.
Open cell for solid stone walls, roof structures, timber applications.
You need to work out what the application is and what you want to achieve. Each has its own benefits.
To conclude though I would no personally put closed cell in a roof structure on a domestic property unless i could be 100% certain that moisture will no be a problem. Im never 100% so i always tread cautiously.
Open cell foams like Icynene have a very low Global warming potential, Closed cell have better thermal values but use foaming agents so have an increased GWP.
For insulating a slate roof i wouldnt try and improve the weather shield using spray foam. Spray foam is insulation and insulation it should stay.
I personally use icynene on slate but only after a lot of work has been done to make sure the slates, ridge tiles and all flashing are perfect. I will then line the inside of the roof with a breathable felt and apply breathable icynene. The felt is only a secondary weather barrier, people think you can fix a roof with spray foam.
If your roof needs water proofing and strengthening its time to get a new roof. Don’t rely on insulation to fix this.
myself and Gary L Maedl have a totally different view on how to use spray foam insulation.
This is not about one is better than another but each has its applications.
Regards
Jonathan
Gary L Maedl says
Hi Jonathan,
You say that you’ve been installing foam for 3 years and have seen many rotted timbers due to the use of rigid closed cell foam in attic structures? How can this be? There is no way that the roof structures would rot that fast, even in tropical regions.
I used rigid closed cell polyurethane foam in for the first time in a home I built in 1975, studied mechanical engineering and polymer chemistry in college, and have been using closed cell rigid foam ever since on all my projects for 38 years. I have never seen any such water penetration or timber rotting as you claim.
Other than your comment that you can’t use spray foam to fix a leaky roof, which is correct, all of the other statements that you are making about the use of foam are questionable at best. This is not a matter of different “views”. It is a matter of facts substantiated by years of experience and, more importantly, published research on these exact topics.
I’m not trying to be a hater. I just want to point out the facts so that people who rely upon what is said here do not get misinformed.
Thanks,
Gary
C Mango says
Hey Jonathan,
Thanks for weighing in. You wouldn’t use closed cell in a roof. Gary wouldn’t use open cell in a roof. I’m sure we could find someone here who wouldn’t use any type of spray foam in a roof due to potential water issues. But I’m also sure someone somewhere is replacing rotted roof boards right now in a roof with no foam, simply because a leak went undetected. Maybe it didn’t penetrate the living space and people rarely go into their attics to look for problems.
I think we’re all in agreement, that the most important thing is to keep water off the roof sheathing/timbers in the first place. I am a little reticent about using anything that might keep a roof leak from manifesting itself.
One other drawback to closed cell is the fire block issue. Having to wrestle 5/8″ drywall into a low-pitch roof attic space would be a pain. I don’t believe this is the case with open cell…not sure.
One question Jonathan, you said closed cell is suitable for walls, but not roofs. OK, what about very steep roofs? Would you put closed cell in your Swiss chalet?
BTW, I appreciate the experienced opinions of both you and Gary on the merits and limitations of open and closed cell insulation.
Mango
Jonathan says
Hey C Mango.
Totally correct, water, moisture, vapour is the biggest issue in a property. Im not just talking about roof leaks.
When you warm your property if you have not got a heat recovery ventilation system you will find that the warm moist air will rise and condensate. The coldest space in a loft with spray foam will be the walls and roof timbers.
If this is the case for extended periods you will be adding moisture to the roof rafters.
You CANNOT fully coat all timbers using closed cell as they need to open on the end to breathe.
Using open cell gives you the ability to spray in between the rafters and totally cover these rafters so the risk of condensation is reduced as you have reduced the cold spots. All of my domestic installs will be sprayed between the rafters and then over the rafters, if the client wants a plasterboard finish we can counter batten or use insulated boards. This provides a well insulated roof with no cold bridging.
Swiss chalet | when insulating this i would also use open cell internally, this would reduce air movement (99% of moisture is transferred via air movement) leaving you with a 1% issue. We would need to see about interstitial condensation and do a u value and condensation risk analysis to determine if the amount of foam was suitable for this application.
Once again each project would need to be assessed and the correct product chosen.
Very steep roofs may differ but im mainly taking about slate / battens / membrane setup.
These membranes need a slight droop to take the water away from the rafters, if you had a really steep roof i cannot see a problem why closed cell couldn’t be used. The chance of water pooling would be reduced.
If i insulate a sold stone wall with a lime render i would always use open cell. This wall needs to breathe.
If i were to insulate a steel/alu panel wall i would stick with closed cell.
Sorry for boring you all but the key is that if there is a problem we need to see it to find it then we can fix it and move on. If we cant see then we cant fix.
Regards
Jonathan
Gary L Maedl says
Jonathan,
C Mango is going to make decisions and take actions based in part on what is written here. I’m sorry, but many of your statements in this post are mistaken and misleading to the reader.
Research and experience is a key prerequisite for giving such advice. Here is an example of research I pulled in a quick Google search: http://www.foamroofing.com/aboutSPF.html
There are literally thousands of such substantiated documents available, and the problem with the Web is that there are many that contradict each other. That’s where experience comes into play.
With respect to your comment that the ceiling and walls would be the coldest spots in a loft, this is not pertinent to the base question. The question is where and why would condensation occur in a foamed roof system.
Condensation occurs when warm moist air strikes a surface whose temperature is below the dew point of the vapor. In a correctly constructed closed cell foamed roof structure, this dew point line occurs beyond the interior face of the foam, close to or at the roof deck surface. Since the closed cell rigid polyurethane foam is impermeable to the water vapor, no condensation can occur on the inside face of the foam. This has been researched and verified by many experts, Oklahoma State University for example, and is what I’ve observed in actual practice for the last 38 years.
Open cell foam would let the water vapor through where it would then hit the dew point line, condense, and saturate the foam from the inside out creating a huge mess.
The point that you make about “bridging” is valid in the case where the rigid foam is sprayed on the underside of the roof deck in between, for example, 2×12 roof rafters. At roughly R1.25/inch for douglas fir timber, a 2×12 (11.125″ thick) rafter would have an R-value of only 13.9. Therefore the fact that exterior cold could travel through the 11.125″ of wood and create a condensing (dew point line) surface on the inside of the structure.
In actual practice, the warmth of the foam on either side of the foamed-in rafter prevents this from happening. But where double rafters occur, especially in valley structures, the facts change a little. Therefore, the roof/insulation structure needs to be designed to take this into account.
You could set the rafters in question up a bit and glue 1″ of polystyrene board along the inner face of the rafters in question. Or you could put a vapor barrier over the entire inner surface of the ceiling directly under the drywall (which is fastened directly to the rafter faces and, in best practices, glued).
But for my construction projects, I typically see to it that double rafters are glued together and the inner seam between them is caulked. The little moisture that may condense on the surface of such double joists is nominal and typically evaporates on its own.
Any good insulation system must be combined with effective HVAC systems which remove high moisture content from the interior air (i.e.- HRVs and ERVs and proper bathroom venting).
Sincerely,
Gary
Todd says
I have read a lot about this issue over the years. greenbuildingadvisor has a wealth of info on this subject as well.
I am not an expert in this field. I can only state what I have read and what I have been contemplating, given condensation issues inside my AC airhandler/ductwork in the attic in the winter.
I have only seen Closed Cell as the clear recommendation for “unvented” roof’s. Open Cell in walls and ceiling (Like fiberglass batts, if the attic is vented.
I can see using open cell in a ceiling but with a vented attic.
While you have the debate about which foam product may work better, prevent condensation, allow a roof to breathe or not, there is another idea to consider.
What about allowing the roof deck to still breathe. If you built a ventilation channel using ripped 2×4’s and plywood between the rafters, this would allow the roof to breathe. Assuming you have soffit vents and a ridge vent. The bottom of this ventilation channel can then be sprayed with foam and you have the best of both worlds, no? A roof that can still breathe and have a way for water to escape in the case of a leak as well as a conditioned attic space.
Gary L Maedl says
Hi Todd,
Your condensation issues with attic based HVAC is common and is the reason that I avoid attic ductwork and systems whenever possible.
Your belief that attics must be ventilated is a holdover from the old days when insulation was minimal and houses were not very tight. There is no need for attic ventilation when a closed cell foam roof system is used.
If you did build the roof deck with the air space you suggest, you would be creating a guaranteed roof rot situation as the moisture from outside would condense on the underside of the roof deck due to the temperature differential between the top of the plywood on the foam side and the roof deck over the air channel.
Again, the roof does not need to breathe as was commonly believed in the old days when buildings were not very tight.
Gary
Todd says
Gary,
Unfortunately, the air handler is in the attic for AC and there is no other possible location without giving up necessary closet/storage space elsewhere. THat’s if it was even possible to relocate to those place.
I do know that the ventilation is a holdover from the old days. I know that “technically” there is no reason for it when using a fully sealed closed cell foam system. I know that hot roofs are fine.
However, I use the quotes on “technically” since that assumes that the original roof is sound, the foam sprayed correctly etc. The latter is an issue I have read about countless times. If the foam is sprayed to thick or incorrectly, not only do you not get the proper r-value but you have cracks and placed for moisture to go.
While ventilated roofs are a hold over, they still are a 100% tried and true way of ensuring that the roof deck remains dry. It is still a preferred method these days for siding installation of wood or even cement based sidings i.e. rain screen. This creates a channel that allows the siding to breathe and stay dry by allowing air to move behind the siding. Somewhat the same principals used to vent a roof.
I don’t understand how you can say that creating a vent channel would create a roof rot situation. How can it? In the winter, the air is cold and dry. No moisture. The bottom of the airspace is a baffle made of plywood to which the closed cell foam is applied. As you stated earlier in your post about the rafters, the closed cell foam would be insulating. This keeps the roof deck and baffle the same temp as the outside while the room below is conditioned roughly to the house temp, assuming duct work here. In the summer its the reverse. There is nothing to condense or can condense. Closed cell foam restricts vapor transmission so no condensation.
What the vent channel gives you is the best of both worlds. Not to mention, it is a security blanket in case there is a failure of the spray foam application. It also allows you to easily replace the roof decking, at a later date, if there was softening or roof rot, since the closed cell foam is not sticking to the bottom of it. In a nutshell, I can’t see any downside, except added cost.
In reality, the perfect insulated roof would be done above the sheathing or rafters. THis has also been done successfully using rigid foam sheets and then adding sheathing and shingles. That totally puts it on the outside of the building envelope where it really belongs. Ensures a fully sealed and continuous thermal barrier and no thermal bridging. Same goes for the outside walls as well.
Gary L Maedl says
Todd,
If the HVAC unit has to be in the attic, what I do is build a little enclosure around it (easily removable for maintenance) that is fully insulated. I also make sure all ductwork is fully insulated.
With regard to rigid foam roof systems, of course it has to be installed correctly. However, too thick is never an issue; only too thin. Doing the spraying when it is too cold outside is the most common mistake. The foam will not adhere correctly.
Ventilated sidewalls, regardless of the type of siding, are NOT the accepted practice. That is a holdover from the old days. The siding does not need to breathe and it does not apply to roof systems either.
I’m sorry if you did not understand why the vent channel on the roof would create rot. The roof deck and the top side of the baffle (against which the foam is sprayed on the underside) are NOT the same temperature. The plywood baffle would always be warmer in the Winter due to heat transmission from the building, through the foam (albeit very much slowed), and through the plywood baffle. Insulation does not stop heat loss; it merely slows its rate of heat transfer.
Your assumption that the air is cold and dry is incorrect. There are warmer days in Winter (i.e.- cold rain just above freezing or warmer) and the water vapor content of the air is quite high on such days. If, for example, it went from say 10ºF overnight to 35ºF in the morning, then air flow through the channel would be moisture laden (from the increased air temp and moisture in the air causing the warmup) and it would condense water onto the underside of the roof deck.
In the Summer, the reverse would be true. An air conditioned home would cause the baffle surface to be colder than the outside air and condensation would occur on this surface instead of the roof deck underside.
With a correctly designed and installed rigid foam roof deck, the waterproof roofing material is where the condensation line now falls, both for the Winter and Summer. In this case, the condensation (which still occurs by the way) is on the surface of the shingles.
The “perfect insulated roof” that you refer to is structurally unsound in any kind of high wind situation. It has been tried before and failed by being ripped off the building by wind.
Gary
Todd says
Gary,
Rain screen might not be the normal practice but it is utilized by many highly skilled contractors in the trade. It may be old school but as others have realized it is really the only tried and true fool proof method of insuring that the siding (especially wood) dries out and prevents heat driven water vapor from entering the building envelope. Have read countless articles on JLC, Greenbuildingadvisor.com as well as Fine Homebuilding. All with the same info. Same with the ventilation in the attic. It might not be in standard practice anymore but many have realized that it is a preferential method.
What you are saying doesn’t seem to make sense. The plywood baffle would not cause condensation in any scenario. The only vapor that could possibly occur is the space between the sheathing side of the plywood baffle and the roof deck. It wouldn’t occur anyway due to the natural air flow and stack effect that would draw air in through the soffits, through the baffle and out the ridge.
I know that insulation does not stop heat loss and only slows it. However, closed cell foam, being a vapor barrier (not retarder) means that water vapor cant pass through it. Thus, you can’t have condensation on the inward facing side of the plywood (Side sprayed with foam) without moisture being present there. Only way you could have water or condensation here is if there was a leak in the roof sheathing. But then the water would have a path out via the plywood baffle and it would also have drying, preventing mold and rot by this same channel.
Not to mention having R48+ on the underside of the plywood baffle reduces temperature differences between the outside to inside. While the air inside the house is 72 degrees and the outside is 10 lets say, the plywood is at the outside temp and so is part of the foam layer. The foam works insulating both ways. Keeping the plywood cold and the inside warm. The foam never heats up to the inside temp but slowly releases heat. The fact that closed cell or open cell for that matter or even dense pack cellulose reduces or eliminates air movement means that the R-value is more true and effective vs a product like fiberglass that does nothing to stop air movement and convection currents.
In order to have condensation, moisture vapor coming from a hot surface will condense on a colder surface. In winter, the house will always be warmer than the ventilation baffle. Since closed cell foam prevents moist humid air from a humidified home to pass through it, there is nothing to condense. THis is also why the code requires a specific qty of vapor impermeable insulation to be used to insulate rafter or roof deck. This number is based on climate zones. The summer is the reverse and the same closed cell foam does not allow the warm moist outside air, that could be in the baffle from passing through the foam. Thus nothing to condense. That same foam is keeping the baffle the same temp as outside as it is keeping the inside cool. That is how insulation works. If not fridges and freezers would be covered in condensation in the winter. Especially, my own placed inside my Hot humid garage. Doesn’t happen.
Gary L Maedl says
Todd,
Tyvek and other exterior wall membrane systems, couple with rigid urethane foam insulation in the wall cavity, are superior building methods. The siding system becomes irrelevant.
I’m sorry that you don’t understand how the baffle system would form condensation. I’ve tried my best to explain it so it would make sense to you. I didn’t make this stuff up. It has been thoroughly researched and proven.
I never said that condensation would form on the inside (building side) of the plywood baffle. If you could stick your hand in the baffle, palm down toward the building space, the plywood on the backside of your hand (the underside of the roof deck) would condensate when it goes from cold to above freezing. The plywood on the palm side of your hand (the plywood on which the foam is sprayed) would condensate when the house is being air conditioned.
While it is true that air flow would dry out this air space, it would do so only when humidities outside were low. In many places (i.e.- Seattle), that never happens and rot ensues. It will rot in virtually all places (with the possible exception of desert locations). It just takes longer in some areas.
Insulation does NOT insulate in both ways. Thermodynamics states that heat always flows to cold; higher energy state to lower energy state migration is how it works according to all laws of heat transfer. Therefore the plywood that the foam is attached to is always warmer in Winter and colder in Summer (if using A/C) than the air flowing through your baffle system. Hence the possibility of condensation.
The water vapor that is condensing in Winter in my example is not coming from inside the house. It is coming from outside. Please read again what I’ve written and it should become clear to you.
The condensation in a refrigerator is primarily occurring on the inside. Why do you think they have frost buildup and need a defrosting system? If the fridge has a bad door seal or poor insulation inside, you will also get condensation on the outer surface. Like a beer cooler.
Gary
Barbara says
Im not an expert but have followed this issue for years. Part of the problem is that there isnt a one fit solution for every home. Seasons change, regions vary and some times atypical weather can cause unexpected conditions. Many of these foam systems are young and dont have 100+ years of data that traditions systems have. (We have Airkrete which we love.)
Im am going to take issue with the gentleman who said that insulation will keep the rafters warm. Bridging is a big issue and rafters are perfectly capable of getting cold and developing condensation even if well insulated on either side. Insulation doesnt generate heat, it only preserves some of it so you will necessarily end up with less heat than you began with. You will end up with condensation sometimes in some parts of the structure. On a cold day I can look at the outside of our wall and “see” all the framing by where the condensation is/is not on the stucco.
I personally feel that back up venting is good but its tricky to control moisture levels in a back up system. Often when you want to vent moisture from the inside, its outside too and so present in your makeup air.
Gary L Maedl says
HI Barbara,
I’ve been using rigid polyurethane foam insulation for over 34 years, and it was around long before I started using it. I don’t regard that as “young”. Maybe you are referring to newer foams like Icynene which I do not use?
Airkrete was patented in 1984 ( http://www.airkrete.com/company.php) so that makes it a lot younger than foam.
As for your statement of exception regarding bridging of cold by rafters, my statements are based upon actual research done by a number of institutions where they built rigid foam and rafter/stud roof/wall units and tested them in the laboratory, and backed up by my observations of many years of actual installations. This is not any opinion. It is a proven fact.
Gary