Spray Foam Insulation - Is it Really that Good?
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Spray foam insulation has become one of the hottest insulation products on the market since the late 1990's. Although this spray application has existed since the 70's, it was not as popular because of the large amounts of formaldehyde in the insulation material. Today there is no formaldehyde, the R-value per inch is at least as good as any other products, and it has the best air sealing abilities of any insulation product currently available. So why isn't everyone insulating with spray foam now? The answer to this is complicated, and so are the choices of spray foam out there.
Closed cell polyurethane spray foam insulation
That's a mouth full in itself. This type of spray foam is considered the best because the multiple cells that make up the foam are encapsulated onto themselves. In other words, they are virtually impentrable to moisture, taking care of any mold worries.
The word "polyurethane" is a fancy way of saying "plastic." So this insulation material is simple a 2 part plastic that when heat is applied and sprayed on a wall or ceiling (or anything), it expands to roughly 50% of it's original size.
There are many varieties of spray foam densities and each density has a slightly different R-value. Most of the spray foam that is used in temperate climates that see great deals of temperature and moisture fluctuation is 2 lb density foam which has an aged R-value of R-6 per inch. The reason there is an aged R-value is because there is a small amount of off gassing that occursas the foam ages. Non of the gases are toxic or hazardous in any way, but they do effect the R-value slightly. For instance, the initial sprayed R-value of 2 lb foam is R-8 per inch. Please note that there is only a small amount of R-value lost, and it has very little effect, if any, on the performance of the insulation. Also, there is no vapor barrier needed with closed cell foam becuase of it's water resistent and air sealing quailities. Anything under 1.5 lb foam is NOT considered closed cell anymore and is now considered open cell foam... which we will get to in a minute.
The major benefits of closed cell foam are numerous. For one, you only need 3 inches in a wall and 5 inches on the ceiling to meet all your code R-values. When using this product, your building is air tight. The only air that comes in is the air you want to come in making your building extremely efficient; from 30-50% more efficient than fiberglass and 10-25% more efficient than wall spray or dense pack cellulose. Now before you go running to the phone, there are of course some major drawbacks. The first is price. It is very expensive at around $4.00 per square foot. It is not uncommon to have a price tag of $13,000 or more for an average house of 1500 square feet with 8 foot ceilings. Generally you see your savings within 5-7 years or less depending on your lifestyle.
Open cell polyurethane spray foam insulation
This type of spray foam is marketed the hardest by a company called Icynene. Icynene has several foam and spray applied products, but there biggest seller is open cell spray foam insulation. Why? It is significantly cheaper than closed cell spray foam and offers the same great air sealing abilities. There are, however, several key differences.
Open cell spray foam insulation is still just plastic that is heated up as it is sprayed in on a wall or ceiling. The difference is because the foam is less stable, it has an aged R-value of R-3.5 per inch, and fills the cavity completely in order to reach code requirements. Because the cells are open, the foam acts and feels like a sponge. There needs to be a spray or brush on vapor barrier applied to the spray foam once the foam has curred (curring takes about 10-20 minutes) in order to prevent moisture absorbtion.
Open cell spray foam is approximately half to three quarters of the price of closed cell foam. It remains popular for this reason. When applied correctly, the energy savings are just as good as closed cell foam.
Pour in Place polyurethane foam insulation
This method of foam insulation started around the 70's also, but never took off until recently. This is currently the most common way to insulate the cores of concrete block walls. It can be used on residential homes as well, existing or new.
This type of foam is a bit different from the others in that is isn't so much heat based for expansion as it is water and pressure based. The foam is roughly about $1 per square foot and offers comperable air sealing qualities to spray applied foams. This is considered a low density .8 - 1 lb foam and is open cell.
One of the main complaints of this type of foam has been shrinkage. It tends to shrink away from the studs if the water and pressure mixture is not correct and I have been told by other contractors that it takes a lot of monitoring to keep the proper consistancy. As for any blind use application with any product some inconsistencies are to be expected.
So Which foam do you choose?
When choosing any insulation product you have to consider the cost, the amount of energy savings, and how long you will be in the property to recoupe those savings. One thing that has raised property values in this bleak economy have been energy efficiency improvements, so that is a factor as well.
All spray foam applications should be performed by a professional. They do sell kits for do-it-yourselfers, but they are tempermental and if you do not know what you are doing, you will waste a lot of money. These kits are about $400 for 200 board feet and $800 for 600 board feet.
Always remember that if you do not know what energy efficent upgrades to do, hire an energy consultant. He/she will go through the building with you, test the entire property for efficiency and give you a report of areas to improve upon. Depending on the state you live in, you may be eligible for some rebates.
For more information on insulation and heating efficiency, click here.
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I had closed cell foam made by demilec corp (called heatlok soy) and it caused my sheetrock to bow in an upward direction up to 1/2" between the joists.
neither the installer or the product manufacturer of the product accept responsibility.
Stay away from Soy based spray foam systems as there are numerous problems with them. Each batch will spray differently, and I have also heard of some smell issues. Stay with traditional spray foam and a reputable contractor. Just because a company has a radio ad doesn't make them good.
Correct. Any spray foam product that uses the oil of soy, castor beans, or any other plant, will spray different everytime. I have sprayed all variations and of the natural ones, the castor bean spray foam was the most consistent. The way you control these foams in with heat. With castor bean oil foam, you simply add more heat and it sprays fine. Soy is tempermental. I have had to remove it from box sills as some batches never mix properly and stay a mushy liquid. Expansion issues can cause problems also.
Also, if you are having existing walls filled with foam, it is NOT closed cell. This foam is open cell as closed cell foam is not pourable. Just because the density is 2 lb foam does not mean that it is closed. THere are open cell foams present in 2 lb variety.
This market is currently being penetrated by a lot of people. Make sure the person you are dealing with is listed with your state's certified contractors for urethane spray foam applications or is part of a professional organization. This stuff can damage your home if applied incorrectly.
One comment I'll give on the topic of which foam do I use, just a simple rule of thumb, open-cell is always less (per board foot) than closed-cell.
I used Foam-It-Green closed cell foam from Guardian Energy Technologies, Inc. to insulate my attic roof and walls. It’s a good product when the gun provided sprays correctly. However, don't believe their advertising. They say that you know it's spraying correctly when it sprays green. That may be true for one shade of green but not for very slight, variations in color (seemingly imperceptible to the human eye).
Using my first kit from them, I followed all their instructions precisely including spraying a test area, removing the nozzle, applying petroleum jelly to the gun, and waiting 60 seconds to confirm that the foam hardened. Then I proceeded to spray bays, confirming that the spray being applied was light green. After having sprayed around 350 square feet, I happened to look back to where I began and saw that some had turned blue and was dripping! Upon closer examination, random parts of the sprayed area had cured correctly, other random areas looked ok except that the spray had not hardened and was tacky, and most of the area was turning blue and melting.
What I learned after wasting an expensive amount of spray foam and having to do extensive clean up of the blue chemical, is that you should use the foam color to tell you it's not spraying correctly if it's not green but, when it is light green, you need to still confirm that it's hardening. What I've done since, very successfully, after replacing that defective spray gun, is to continually confirm that the bay(s) sprayed a minute or so ago, have hardened.
I’m very disappointed in Guardian Energy Technologies. Although they obviously spent a lot of time and money on instructions to help you spray correctly, they didn’t cover this point that resulted in 300 or so square feet of wasted foam. Although their Product Details says “• 100% Warranted Against Defect and 99.9% Free from Defects - Your Purchase is Risk Free” and I followed their instructions precisely, they insist that the waste is my fault. Every time I speak to them, they come up with a different reason, for example, “you didn’t measure the temperature of the surface that you were spraying; it was probably too hot”. The morning that I sprayed successfully after that first morning’s disaster, the temperatures were even warmer than when I had the problem. Their answer to that is that, even though it sprays well at a certain surface temperature at one time, it might not at another time. I think that gives you an idea of how difficult they make any conversation about their giving some consideration for problems with their kit.
Joe Bee. if the spray color is Green then its 99% Castor Oil based. These are not very good or consistent despite the "green" marketing hype
I'm with you Keith. I swear by the stuff too. And the costs are not a concern in the right situation. But you need an energy audit to determine that. There are many rebates and tax credits for this type of improvement depending on your location.
I spray foam day in and day out all day, ive used many different types such as guardian, Dow, BASF, Lapolla. both hard, soft, and different colors. The worst reaction ive had was with Dow, and it shrunk causing the boards to warp. i spray new/old houses, crawlspaces, pole barns,attics, hottubs. the list goes on. spray foam is the best insulation you can get...for now. It keeps bugs and rodents out and is water resistant, But the soy is not good for country houses or pole barns as the mice will eventually eat through it. To what joebee said, the temperature shouldnt of made that much difference. as long as the chemical was a constant 120 degrees. you just have to spray a really light coat the first time and let it harden, should get hard in 10-20 seconds. the reason it looked like it was melting was because you werent getting the chemicals mixed correctly. either to much A or to much B at one time. check out my page on youtube 8906cwf i have a video showing me spraying a pole barn with closed cell Guardian foam
KeithTax Level 4 Commenter 2 years ago
I used closed cell foam on much of my home and in the utility room of the barn. I swear by the stuff. It really cut my heat bill. Good report.