Icynene foam insulation/ soy foam
We’re using a “bio-based” soy foam insulation on my latest job. The customer became interested in using icynene foam insulation, then found out about a soy based product which is being sprayed in the house as I write this. The stuff is cool. Expensive though. It looks just like the foam that comes in a can, but they spray a whole house with about two fifty gallon drums. It expands at a rate of 100:1.
I would like to hear from anyone who has any experience with these types of foam. Three issues that I would like to bring up about this product are r-value, roof venting, and vapor barriers.
1. Though it has an r-value of 3.7 per inch the foam people claim that only 6″ is necessary in a roof. In the upper midwest, we usually use r-38 minimum when installing fiberglass.
2. We talked with two installers of foam, one of icynene, and one of bio-based foam(soy). Both were so confident in the sealing qualities of their products that they encouraged us to spray directly on the roof and forego any venting. I vented it. Giving moisture an escape route is always a good idea in my book.
3. The product literature claims that no vapor barrier is necessary “unless the home is located in a climate as cold or colder than Madison, WI.” In the case of a cold climate, vapor barrier paint is suggested as “adequate.” The foam is permeable to water. A plastic vapor barrier is cheap, and I plan on using one!
Replies
Dan,
I'm located in Central PA and just had my house sprayed with Icynene, 2x6 walls and 2x10 second floor ceiling joists. I had a five foot knee wall on the second floor, so there is a angled ceiling in each room. I also vented my attic. My installer wanted to spray the attic rafters and the teck department said it was fine also. But, like you, I wanted a vented roof. I think it's like a dome effect going up the bedroom rafteres and along the ceing joists and didn't see any reason the let the heat pass through the drywall to the attic. Since I had it sprayed I hired a guy to help me frame my garage who was helping spray my place and he also agrees with a vented roof.
3000 sq. ft. 2x6 house with a 600 sq. ft. of 2x4 basement...........$5900
The only hard part I can see is if we EVER finish and move in will be getting used to how quiet it is and not hearing the wind and weather.
I also installed a Energy Recovery Ventilator from Aprilaire to exchange the stale air and to allow doors , range hoods to work properly.
Good Luck
Rupert
Hey Rupert Wow $5900 for Icynene thats a good deal!I'm building the same size house and the prices I got in CT were $16,000&$17,000 I need to friggin move LOL
One of the dome builders looked at the soy foam. We aren't currently using it primarily be/c it doesn't have the density we require of ?2.5#.
"it doesn't have the density we require of ?2.5#."
Can you please explain what this means?
We are restoring a Victorian (ca 1896) house. We are the 3rd owners and fortunate (mostly) that the house hasn't been "ruined" or modernized by the previous owner. Of course, this also means we have an outdated kitchen, only one bath (also outdated) and no insulation. We've been looking at Icynene, but I need to be a little more comfortable that it won't cause chemical sensitivity problems. The soy foam sounds interesting - but I've never heard of it. Do you know any place where I can get more info?Ellen
Foams have different densities, and they are measured in pounds per board ft or cu ft...really not certain. Higher weights...2.5, 2.7, 3.0 are harder and denser and more useful for my application, where I have to support rebar and also walk on it. Icynene doesnt come with the same requirements, and so density doesn't matter in the same way. The soy stuff may be an alternative to icynene, but won't currently substitute well for many uses of polyurethane.
Some of the symbols I used looked bad be/c they apparently didn't translate well from a Macintosh to your computer. It was a "greater than or equal to" symbol before the 2.5.
Soy is food,
are there borates in this stuff to keep it from becoming bug food?
Mice food too.
?
Norm
Ellen, Poly foam with a density of 1.7 # per cu ft will yield about r-7 per inch. Where are you considering using foam, ie., have you gutted the interior and have open walls where the foam can be sprayed on?
Or, are you talking a layer in the attic?
I have not heard of soy foam, or an application that would use rebar to reinforce foam suitable for a walking surface. That doesn't mean its not out there, but if that new, I wouldn't rush to install it.
Paul
Energy Consultant and author of Practical Energy Cost Reduction for the Home
>I have not heard of soy foam, or an application that would use rebar to reinforce foam suitable for a walking surface. That doesn't mean its not out there, but if that new, I wouldn't rush to install it.
You misread. We use foam for insulating thin-shell concrete structures. See the back cover of FHB one issue ago. On the inside of that we hang rebar that is then encased in shotcrete.......but for a short time, the foam and air pressure support the weight of the rebar. After the fact, we coat the exterior surfaces with whatever finish is called for, and in the process, walk on the foam, just as happens on insulated flat roofs. Soy-based foams (http://www.soyfoam.com/ and http://www.biobond.com/index.html) are approx .5# density and are therefore not useful for those purposes. They may very well be appropriate in applications where a higher density is not a factor, such as stud bays.
Cloud, Thanks for clearing that up for me. PaulEnergy Consultant and author of Practical Energy Cost Reduction for the Home
We need to do our whole house. I think I mentioned that is was built around 1896, and we are the third owners. There is absolutely no insulation. As the house has never been updated significantly, we are approaching this as a restoration project - repairing the few places where the plaster has separated from the lath, refinishing wood that has alligatored varnish (but no paint.) Luckily the house does have 110 service, just not much of it, and a fairly new furnace and water heater, but that's about all we bought that was new.)
Our big dollars in the 1st 2 years were spent putting on a new roof; wiring the basement and 1st floors, so we could do laundry at home and plug in lights; hiring abestos abatement for the kitchen floor and counters; and repairing plaster and strippign woodwork in the worst of the rooms. Later this month, we've got a handyman coming to help up remove the attic floorboards (probably pine, but 1" x8-10") When the attic floor is up (and subflooring laid in place, but not fastened) we can get the electrician back to wire the 2nd floor and rough wire the attic. Once we have all the wires run through the exterior walls, we need to get the house insulated. My understanding is that icynene is installed through holes in the interior walls - this is definitely what we want for the 1st and 2nd floors. We are also planning to finish the attic, and need to figure out what we are doing to insulate that.Ellen
>My understanding is that icynene is installed through holes in the interior walls
Cellulose is installed in that way. When I've seen icynene, it was in open stud bays, and the excess was cut off flush with the face of the stud.
From the icynene website:
"The Icynene Insulation System¯ can seal wall, floor, ceiling cavities and crawl spaces completely without having to gut the interior of the home. A special formulation is injected in a one-inch hole, drilled in the wall. The liquid expands inside the wall, sealing irregular surfaces with ease."
The open bay installation sounds appropriate for our attic, though, as we plan to insulate that during the construction process.Ellen
Cool. I haven't seen it done that way. Probably takes a deft touch by the applicator to not overfill or make a mess. That'd be interesting to watch.
I have a friend who had it done and loves the results. She's also got an old Victorian that needs work, but she is about 8 years ahead of us. She was thrilled to finally be warm in the winter.Ellen
Ellen, Some foams are installed in open bay only to avoid over pressuring
a wall cavity, or pinching a window frame. Corbond states open wall only.
I had a client do a concrete block wall by injection with polyurethane foam, but wall distortion was not an issue with block.
For the attic, I would spray an inch of foam, which will seal the joints,holes etc. Depending on application, add batts or cellulose.
Paul
Energy Consultant and author of Practical Energy Cost Reduction for the Home
Wow! I guess I'm not the only person interested in poly foam insulation. The soy guys finished up today and headed back to Iowa. They did an excellent job. This house is about 1800 s.f. with two stories and lots of corners. The second floor has 6' kneewalls with flat ceilings in some areas and cathedral in the master bedroom. There were lots of odd shapes and nooks and crannies to insulate. The home is about 100 years old. We stripped the siding, gutted it, built a kitchen addition, and have been working on it since late April. The soy foam guys charged $5,000.00 bucks for the job and said they were doing it nearly at cost when you consider the travel expenses and lodging ( the drove seven hours to get here!). They also sprayed all the exposed foundation in the crawlspace. It looks like the homeowner will be able to heat the place with a candle. We'll see. I have no idea wether or not the soy foam is attractive as a food to bugs and mice. We joked that the stuff smelled like tofu, but actually it had a mild chemical smell that dissipated fairly quickly.
As with any new product it's easy to be a skeptic. How come we use 12" of fiberglass at r-38 and now these guys are saying that 6" of foam will suffice? This foam insulation is not very common in my relatively remote area, how common is it in cities? Are developers spraying it in scads of new homes? Most people I talk to think that spray foam is expensive, but compared to what? If my crew and I do a bang up job, carefully cutting and installing fiberglass batts and sealing the vapor barrier, I doubt the cost difference is really that signifigant. If these foams became more popular, perhaps the cost would derease.
In the three sites that I gave above, they all made essentially the same claim that the soy foam had no food value and thus would not be eaten by termites or ants. One also said that termites or ants would show no interest in it. However, I have my doubts about carpenter ants showing no interest in the stuff. I had a piece of fiberglass bat insulation that had been laying on the ground outside for a number of months with the foil side facing up. When I picked it up, the carpenter ants were scurrying out with their eggs and ready to do battle. They had chewed a number of tunnels into the fiberglass bat. If carpenter ants will chew through faberglass batting to create a nest, I can't imagine that they wouldn't love to tunnel in soy foam unless there was some type of chemical deterrent in the stuff - and none of the websites regarding soy mentioned anything about boric acid or any other insect deterrence.
Carpenter Ants will only attack WET wood. Remove the moisture problem and the ants go away. I am sure the same thing would happen with the FG or Spray foam. And since spray foam can not hold water like FG I dont think it will be a problem.
>I can't imagine that they wouldn't love to tunnel in soy foam unless there was some type of chemical deterrent in the stuff - and none of the websites regarding soy mentioned anything about boric acid or any other insect deterrence.
Just saw this explanation--
"Though it is made from an organic material--soybeans--the extracted soybean oil has no food value whatsoever thus insects and rodents derive no nourishment from it and will not consume it." Walls and Ceilings magazine
Of course, that doesn't mean things won't burrow into it, I guess...
Carpenter ants don't need no nurishment from soy... They tunnel through fiberglass bats just to exercise their mandibles. And my area is a convention center for carpenter ants. Can't help but think the stuff would become an extended nursery for baby carpenter ants.
I mentioned in an earlier post some weeks back that a contractor friend of mine used the icynene foam on his house. He is anticipating very low heat bills this coming winter and has propane heat installed. The only real problems I noticed when I looked over the installation were that the foam, when oversprayed, had a tendency to push the hi-r sheathing out from the wall and that it mangled up several of the plastic soffit vents in the truss bays. I'm of the opinion that the soy stuff will probably be commercially successful in a residential application. Being more a natural substance is going to appeal to a large market of homebuyers and the sealant properties of spray insulation are already making it more popular than the old-fashion batt insulation.
Dan,
You make a powerful point. If your crew does batt insulation perfectly, and if you value the efficiency of sealing and R-value, is foam more costly? I agree with you...foam is a bargain when used to its best advantages.
I like the combination of foam, batt and cellulose for great results at reasonable cost. In a 2x6 wall, I would spray in 1" of closed cell polyurethane(R-7), and finish with 6" batt. The batt would be slightly compressed and not yield r-19, but the combo would certainly yield R-25 air tight walls. (there is an R-21 6" batt also)
In an attic, with 2x10 floor joists, I would spray in 1"-2" of foam, including some over spray on the top of the joists and finish with cellulose for the desired R-value. Where I wanted attic decking, I would increase the foam thickness to 6-7 inches, and keep the top of the joists clean for the plywood. I would place my duct work between joists where ever possible, and foam them in, including the boots at the ceiling registers. And, if I had the sprayer in my hand, I would hit the trunk lines as well.
If in ice dam territory, it would be nice to have the foam sprayer hit the first three feet of roof deck at the eves with a skim coat.
Install a radiant barrier to continuous vented soffits, install a moderate exhaust fan to suck the air from behind the rad barrier, and I would have an attic that stayed close to ambient air temp, well isolated from the house conditioned air and my forced air system well sealed and insulated from the attic temp as well. (I like to run the air handler fan to filter air, but I don't like to pick up heat gain nor loose winter house heat through the duct work)
Some other foam applications:
I have had foam installers hit the under sides of hot tubs and the back and sides of shower stalls with an inch or so. Quieter and warmer.I set a fiberglass shower/tub on concrete in a basement bath, and then had it foamed in under support blocks and bottom. Great isolation from the concrete, and made the tub bottom quite solid when standing on it.
I had a basement block wall foam filled. If the foam had been sprayed on the basement interior walls, the foam would have had to be sheet rocked before occupancy per code. In or under a house, any foam should be fire blocked. Attic is the exception due to being above the living level.
I am not up to date on soy foam (sounds like an Oriental dessert) but I like the R-7 poly foam .
Sorry for the long commentary, but you seem hands on / interested.
Paul
Energy Consultant and author of Practical Energy Cost Reduction for the Home
There are a number of articles on the Web regarding soy based insulation, but all of it seems to be by the soybean industry or those wanting to sell you the insulation. I found no articles by what appeared to be unbiased sources. I found three companies that want to train you, sell you the equipment, and supply the soy insulation solutions:
http://www.biobased.net/
http://www.soyfoam.com/
http://www.healthyseal.com/
Could be more.
Hmm...time for a FHB article on the stuff?
Darrel FYI ... the 2003 August edition of the Journal of Light Construction (p. 65) does a nice job of describing spraying polyurethane foam; pros/cons, manufactures, applications etc.
Hey Dan
I have ben a partner in the Polyurethane foam insulation business for almost 3 years now, and in the 3 years we have learned a lot. When we first started out we were instructed to spray the poly on the underside of the roof, but to me I could not figure out why you want heat and cool you attic. So we went out on a limb and started spraying in on the drywall celing, and I thing this is the best way to do it in my opinion.
We have also found the here in the midwest that 4" to 5" works best for the roof and 3" in the walls no matter if it is 2x4 or 2x6. Last winter we sprayed a house the had at one time ben bat insulation but due to a fire when the H/O remolded the chose to go with poly, they reported a $35 savings on their heating bill, this summer the reported a $45 savings. So thing that you need the R 38 or better in the attic area but with the poly you don't have the heat transfer like you do with batt insulation.
It has take 3 years to get were we wanted to be and finally start making a profit, but in my opening this is the best type of insulation on the market. We had some thermal imaging done last winter with the temp at 15, and we found the heat loss was 95% more on the studs than the void between the studs.
Geez does this mean that we are gona hafta start puting thermal breaks in our framing too?!