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Green Building News

Three Massachusetts Home Fires Linked to Spray-Foam Installation

The Massachusetts Division of Fire Safety warns fire chiefs about the dangers of negligent installations of spray polyurethane foam

Fire investigators suspect that a fire that destroyed a $5 million home in Woods Hole, Mass., was ignited when excess heat was generated by the exothermic reaction that occurs during the installation of spray polyurethane foam. [Photo credit: Dave Curran]
Image Credit: Dave Curran

UPDATED 8/16/2011

The Massachusetts Division of Fire Safety (DFS) is investigating the causes of three house fires that were ignited while insulation contractors were installing spray polyurethane foam.

According to Tim Rodrique, the director of the DFS, investigators suspect that the fires were caused by the exothermic reaction that results from the mixing of the two chemicals used to make spray foam.

A $5 million house is destroyed

One of the fires destroyed a $5 million home on the exclusive Penzance Point peninsula in Woods Hole on February 10, 2011.

The house was being renovated at the time. According to the Cape Cod Times, “firefighters were somewhat stymied due to spray-on foam insulation. … Similar insulation has proven deadly in the past. In 2008, Robert Cowhey of Springfield was spraying soy-based foam insulation in the attic of a North Falmouth home. The chemicals were located in a truck outside the home in two 50-gallon tanks, but somehow they ignited and Cowhey died in the ensuing fire.”

Robert Cowhey, the victim who died in the North Falmouth fire, worked for Green Mountain Insulation of White River Junction, Vermont. Cowhey was installing SoyTherm50 spray foam insulation when the fire broke out.

According to the Cape Cod Times, “The first sign of trouble came when a co-worker smelled a burning odor and noticed smoke billowing in the fireplace on the floor beneath the attic. He and another worker tried to reach Cowhey and put out the fire with an extinguisher. The two were stymied by the intense heat and smoke, however.”

According to an OSHA report on the North Falmouth fire, “The company was spraying expanding foam insulation in the attic of a single-family, two-story house that was undergoing renovations. The spray foam properties were such that it could generate sufficient heat immediately following its application to cause spontaneous combustion. Among the chemicals being used were diisocyanate; flouroethane and lead naphthenate. There was no fire extinguisher in the attic space during the spraying process and no rescue plan in the event of a medical emergency. The employer had not developed or implemented a fire protection or prevention plan. Access to the attic was via a 3’ wide by 6’ long hole in the second floor ceiling. The attic was not ventilated. A flash fire occurred in the attic in which an employee died.”

OSHA further notes that “the products used were SoyTherm 50 and SoyTherm 100 and are diphenylmethane diisocyanate (MDI) based. A technical bulletin issued in November of 1993 by the Polyurethane Division of the Society of the Plastics Industry, Incorporated located in New York City warns of the spontaneous combustibility of the material. SoyTherm is known in the industry as an open cell foam insulation.”

A warning is issued to all Massachusetts fire departments

On July 1, 2011, Stephen D. Coan, the Massachusetts State Fire Marshal, issued a memorandum to the heads of every fire department in the state. The memo notes, “Recently, the Department of Fire Services, Division of Fire Safety, has become aware of a number of fires involving commercially available spray-on foam insulation. At least 3 fires, one being a fatal fire, are believed to have been started during the application of spray foam insulation, and currently remain under investigation. …

“Information gathered by the Division of Fire Safety from different manufacturers indicate that there are several possible scenarios that could lead to a heat build-up, and a possible fire scenario. These are: improper application techniques (excessive thickness, or spraying new material into the already applied rising foam) and/or improper mixtures of the chemicals at the application nozzle.

“Based upon this information, the Division of Fire Safety is recommending that you work with your building officials to determine if such applications are taking place within your community and, if so, to also make contractors in your communities aware of this potential fire hazard and encourage that they follow application instructions accurately.”

A similar case in Quebec

In a case similar to the Massachusetts fires, a net-zero-energy house in Hudson, Quebec burned to the ground on May 25, 2010. The Quebec fire erupted a short time after workers finished insulating the home with spray-foam insulation. In all of these cases, investigators assume that installers applied the spray foam too thickly, thereby trapping the heat generated by the chemical reaction that creates the foam.


  1. user-998246 | | #1

    foam has also been ignited by over insulating wiring or
    conduits in wall cavities. This is especially relevant when considering retrofits where expasion foam is sprayed into an existing home's wall cavities.

  2. Andrea Lemon | | #2

    How long after installation do you think there's a risk of fire? Hours? Days?

    We're about to make some big insulation decisions on our new construction, and "risk of deadly fires" is a factor worth weighing.

  3. GBA Editor
    Martin Holladay | | #3

    Response to Andrea
    Here's what architect Sevag Pogharian told me about the fire at his net-zero-energy house in Quebec: "At 2:30 the spray-foam installers packed it up. I was on site the entire day. I left the site at 3:00. By 5:30 there was a blaze emanating from the attic space, and the neighbors called the fire department."

  4. jbmoyer | | #4

    Story 1,000 of why you shouldn't use spray foam.

  5. Elden Lindamood | | #5

    "over insulating" wiring
    Brian M. It seems to me that the cited article states that excessive ampacity can cause excessive heat, which can cause polyurethane foam to carbonize and create an arcing path, thus leading to fire. I think it is a little misguiding to infer simply that "foam has been ignited by over-insulating wire". Foam may be more susceptable to this particular scenario than other insulations, but the "cause" is excessive ampacity, not the spray foam.
    I express this not to defend spray foam, per se, but for the sake of preventing the uninformed rumor that spray foam causes wires to overheat and set fires, which it doesn't under normal conditions.
    I also do not see anyplace in the article that addresses the condition in conduited wire, and actually fail to see how spray foams can worsen the situation in an overloaded wire within a conduit given the scenario above (unless I missed it when I [admittedly] skimmed the article).
    I suppose you could make a case that you should be careful with the application in a old house where there may be 4 power strips plugged into a room's singe outlet (or avoind that scenario altogether), but let's not overreact and spur misinformation.

  6. hrNbGskXEM | | #6

    Homeowners and architects are seduced by the R-value of high-density polyurethane without sufficiently understanding or considering the risks associated with this product. As an architect and developer, I paid a very high price for this seduction. Consider the following:
    1. Polyurethane insulation is a product that can spontaneously combust under certain conditions, as illustrated in the above article.  This aspect of polyurethane is not well-known;
    2. Polyurethane insulation is an accelerant. Once a polyurethane fire starts, the property is usually totally lost. Whether this fire starts spontaneously during the polyurethane application or due to some other cause, when heated, polyurethane gives off a highly combustible gas which causes an instant flashover. For this reason, the insurance industry refers to polyurethane insulation as “solid gasoline;”
    3. Polyurethane insulation, in a fire, creates a thick black smoke which obscures vision and causes rapid asphyxiation;
    4. Polyurethane insulation involves, during its application, a propellant that has a global warming potential in the thousands. CO2, by contrast, is benign with a global warming potential of only one;
    5. Polyurethane insulation, due to its inflammability, contains fire retardant (FR) chemicals. "Most of these FRs have not been adequately evaluated for their impact on human health and the environment. When tested, many are found to be persistent, bioaccumulative, and/or toxic. Being persistent means that they do not break down into safer chemicals in the environment over months or years. Being bioaccumulative means that they accumulate in plants and animals, becoming more concentrated as they move up the food chain. Additionally, some of these FRs are carcinogens, mutagens, and/or reproductive, neurological, thyroid, and/or developmental toxicants" (from:
    6. Finally, polyurethane insulation represents a risk even at the end of its life-cycle, i.e. during building demolition. This point is illustrated by the recent warehouse fire that occurred in London, England, in the north of the Olympic Park during demolition work. This fire was caused by the ignition of polyurethane insulation material while steel piping was being cut using an oxy-acetylene torch.
    As I see it, the risks of polyurethane outweigh the benefits.

  7. Expert Member
    ARMANDO COBO | | #7

    Hysteria will follow...
    Alcohol, cars and guns do not kill people by itself either… there are thousand of homes sprayed every day in the US and in very rare occasions there is a fire. Manufacturer instructions and OSHA regulations must be followed. I attended a FREE half day training by Demilec and OSHA a month a go here in Dallas. It was amazing to see few installers and even less builders there. Surpriced???

  8. wjrobinson | | #8

    We just had a local toddler
    We just had a local toddler kill his friend... Our community is very upset ... If that home had no gun to safely store, we would be much happier today.
    Just sayin

    As to foam, low density Icynene is one of the safest foams.... However I do agree that we can build without spray foam and achieve passive house levels of low to no energy demand.

  9. capnkent | | #9

    Green product?
    I appreciate the comments by Sevag... he substantiates the arguement that spray foam is really not a good green product in several ways. Interesting too, that the article mentions it was a "soy" based product!

    In a lesser way, this product seems a similar reflection of nuclear power problems and the energy industry...

  10. dAGujY4nbn | | #10

    This is an extremely rare incident
    Its extremely rare to read about this type of accident for a specific reason which is that as a contractor you are aware of the concept of exothermic reaction or as we call in in the industry, core burn. Working in the Dallas/ Fort Worth area where at one point there was over a hundred spray foam contractors, there has been only one major fire due to spray foam application in the past ten years. The cause of the fire was a closed cell foam sprayed more than two inches thick in one pass. This caused the exothermic reaction that caused the house to go up in smoke.
    If you have a contractor that knows what they are doing and respects the product in the way it should be that should never happen. Remember that you get what you pay for when it comes to your quotes, there is a reason why they tend to be the lowest.
    Ask for references like all other trades and make sure that you are not asking for more foam than is necessary. I have turn projects down because the architect wanted 5 inches of closed cell foam where 2 and a half would do because they felt more was better. If your contractor is properly trained, they will tell you 5 1/2 to 6 inches of open cell foam or 3 inches of closed cell foam is enough insulation.
    As for Andrea's question, Core burn or Exothermic Fires are quickly noticed. There is a very strong smell like burning caramel and small wisps of smoke will be released from the foam itself. The contractor at this point can then crack the top layer of the foam and pull it off, allowing the trapped heat to escape. The reason the foam catches on fire is due to the heat trapped between layers, once the layer is broken, the heat can then escape. Once the foam is no longer insulating the exothermic reaction, the risks of fire greatly diminishes.
    As for improper chemical mixture, this is extremely unlikely as the the foam can only react when the two chemicals mix properly. Foam is a plural system meaning that there is a resin side and an isocynate side, sort of like epoxy you buy at the store. If there is two much of one chemical at any time one of three things happen:
    1) too much resin and the foam comes out too creamy and does not expand
    2) too much isocynate and the foam comes out too crispy and does not expand
    3) the gun the foam is applied with crosses over and forms foam inside the gun and your contractor has to spend hours cleaning it out and no foam makes it to the substrate.
    None of these conditions are at any risk of causing the foam to catch fire.
    As Armando stated before me, training is the key to preventing any kind of risks that are alleged with spray foam. We both work in the same city and have never met, but it shows that there are contractors that take the time to learn how to properly use the products that they sell. While I was not at the Demilac training, I work heavy with my manufacture, SWD Urethane, with training and support due to their excellent continuing education classes. Like any trade, this training is crucial to staying ahead of any potential risks involved with not just spray foam but any other type of material

  11. fTdj6jTjaM | | #11

    Foam fire and our perspective
    Let us all not all go off the deep end here and make spray foam the green industry punching bag. This case again speaks to error in the installation process. Sprayed in place foam when used in accordance to factory standards by trained applicators that care, is safe. I see the potential however for more of this bad press for foam as a new generation of not so committed foam applicators are buying equipment and doing things with spray foam that should not be done. This is an emerging building product in our industry and is growing faster in popularity than it can be regulated. There are far more cases where homes that have been sprayed with foam insulation were actually saved we just don't hear about them. One of the critical ingredients to support combustion is air. Homes with foam insulation allow less air and often have trouble supporting the combustion needed for a small fireplace. Let’s all take a deep breath evaluate our thermal goals and use the products available that make the most sense for the application. There are plenty of people killed, injured for life as well as properties loss to accidents associated with all the other insulation materials.

  12. hrNbGskXEM | | #12

    Plenty of Deaths and Injuries?
    Paul, how many deaths, injuries and loss of property can you list resulting from rock wool insulation?

  13. GBA Editor
    Martin Holladay | | #13

    Response to Joshua
    You wrote, "If your contractor is properly trained, they will tell you 5 1/2 to 6 inches of open cell foam or 3 inches of closed cell foam is enough insulation."

    That's all fine and good if you want R-20 insulation in your house. But what if you want R-40?

    It sounds like you are implying that a well-trained foam installer would tell me, "I can't install R-40 in your house because there is a risk that I might burn your house down."

    Sorry, Joshua. Your line of reasoning just sent me to the cellulose guy.

  14. user-1004357 | | #14

    Free foam education offer
    With so many people getting to the spray foam industry the most important thing to remember is that just like any other trade you have to be properly trained and educated. Applicators are taught time and time again it is imperative that they do not spray too much foam too quickly. I do free training and educational seminars on spray foam insulation and if anyone is interested in learning more please contact me at 860-970-3515 or [email protected] I offer AIA accredited courses in the Northeast As well as educational courses for applicators. Let's not focus energy on the 1/2% of problem cases, let's instead focus our energy on getting the rest done safely and correctly

  15. Zndnus7Qtw | | #15

    SPF and Insulation
    As several have pointed out, a bad electrician can burn down a house too. Poor application is not the fault of the material. Much of the rest of Sevag's objections to spray foam are also wrong. It is not an accelerant. If it were, it wouldn't be allowed in building code, and teh insurance industry wouldn't insure homes that have "solid gasoline" now would they? In fact, part of the mixture is fire retardent, just like the retardent in cellulose. It does not cause flash-over (where do you get this stuff?); in fact it only burns AT flash over. You can hold a blow torch to closed cell (I have) and it only carbonizes -- no smoke, no melting, no dripping, no fire. It only spontaneously combusts under the conditions spelled out by Joshua. As far as Green house gas emissions, McKinsey did an analysis, and determined that the amount of CO2 and other GHG potential generated by the manufacture and embodied in the material is 1/300th of the GHG saved by using the material to avoid fossil fuel consumption.
    To answer Martin, ALL insulation products have a diminishing return problem. Thicker product does not mean more R value. After 4 inches of anything, the added R drops rapidly. He would tell you stop at 4 inches not because of fire hazard, but because it's a waste of your money. The best insulation to achieve R 40 is a a hybrid or mtuliple materials such as 2-3 inches of closed cell spray foam on your exterior sheathing and open cell or fiberglass batts (or celluslose -- didn't know anyone still used newspaper) in the wall cavities. Your greatest cause of heating and cooling loss is not the R value, but pentrations in your building's air barrier that allows unconditioned air to move through your walls and ceiling. The greatest value of closed cell spray foam is that - when properly applied - it makes your house tight, reducing unwanted air exchange with outside air. Secondarily it has twice the R value of fiberglass and cellulose, and it's a vapor barrier, it's a bulk water barrier, and it's extremely structural. It replaces 2 or 3 other building envelope materials. It's greatest drawback is that In some cases it is TOO GOOD, and can make a house TOO TIGHT, requiring additional mechanical ventilation (an air exchanger, $100). This is engineering fact, not hearsay and mythology. It is becoming the preferred insulation in the housing industry in Canada. Use there is much more prolific than in the U.S., and they have a far more rigid building code stystem than we do. If all (heck, any) of the things that our architect friend said are true, they would never have approved it for use, nor would any city building department in the U.S.
    But don't take my word for it; look up Joseph Lstiburek (Ph.D., P.Eng., ASHRAE Fellow) of Building Science Corporation, and see what he says. He loves the stuff and uses it in all of his "perfect wall" designs.

  16. GBA Editor
    Martin Holladay | | #16

    Response to Robert Smith
    Sorry, but you are just plain wrong.

    You wrote, "Thicker product does not mean more R value."

    Yes it does -- with spray foam or cellulose. If you double the thickness, you double the R-value.

    You wrote, "After 4 inches of anything, the added R drops rapidly."

    That's simply untrue. Four inches of cellulose has an R-value of about R-15. Sixteen inches of cellulose has an R-value of R-60.

    I'm afraid that misstatements like yours are all too commonly made by spray-foam installers. Once you trip yourself up with technical errors on basic stuff like R-value measurements, all of your claims will be received with great skepticism.

  17. Zndnus7Qtw | | #17

    Andrea's Concern
    I forgot to add, for Andrea -- you don't have to wait a few hours or sayds or whatever, to see if the house is burning, anymore than you have to wait after it's wired to see if it will burn. You DO have to wait, minimally 4 hours, usually 8 or more, after spraying to allow the material to complete curing. During this time the chemical curing reaction has been known to give off ow levels of isocyanates, and a small percentage of the population, if exposed, can become sensitized and experience asthma-like conditions if again exposed. That's why applicators are supposed to wear respirators, suits, gloves and booties.

    There are rare cases of the application smelling afterward. I read that this was a case of an UNCERTIFIED, LOW BID sprayer who set the proportioner incorrectly (untrained) and mixed the chemicals incorrectly, so it never cured correctly.

  18. Zndnus7Qtw | | #18

    Response to Martin Holladay
    Sorry, I was out doing some weekend errands.

    First, I am not a spray foam installer. I am a building energy auditor and engineer. I happen to believe SPF is one of the best materials for commercial and residential building envelope applications, as long as it's applied correctly, to include ASHRAE Manual J analysis to ensure proper sizing of mechanical ventilation. I believe blower door testing is advised, to determine if a tighter building is needed, and after use of SPF to determine the need for additional mechanical ventilation.

    But to your point about R values. You’re right; more thickness adds more R Value. However, the problem is the common misconception that doubling the R equals doubles the insulative value. It doesn’t. Twice the R does not equate to doubling the capacity of the material to slow or stop heat transfer. I should have used U Value, which measures how much heat is actually flowing through a material, versus the resistance value of the material (R value).
    R value is the inverse of U value (“U” represents the heat flow in BTUs per hour, per square foot of area, per degree of temperature difference between the warmer and cooler sides of a construction). I assume readers understand BTUs -- just think of it as heat.

    So, an R-value of 3 represents a U-value (inverse of R) of 1÷3, or 0.333 BTUs per hour passing through every square foot of insulated area. When we add another inch and double the R to 6, we get 1÷6, or 0.167 BTUs passing through per hour. In other words, the second inch doesn’t double the insulative effect of the material (that would be .67 BTUs; instead it only gets to 50% of the first inch). Double the thickness again that to 4 inches, an R value 12. Heat flow is 1÷12, or 0.083 BTUs. So, four inches does not result in four times as much heat (BTU) flow stopped. In this case, the fourth inch of material only added a flow reduction of 0.084 BTUs, not the .33 BTUs of the first inch or even the 0.167 BTUs of the second inch. It's just math. R 40 is not "twice as good" at insulting your home as R 20. Adding more of the same material does not arithmetically increase the insulative value of the wall or roof assembly.
    This is what I meant by diminishing returns of simply adding thicker amounts of the same material. This is why a respectable, knowledgeable, SPF provider would tell you that adding more than 3 inches will add some fractional insulative value, but not enough to be worth the additional cost.

    To my point about air barriers, which Martin did not address. The R value of fiberglass, cellulose and spray foam is based almost entirely on the air trapped in the fibrous material (in the case of spray foam, the air is trapped in the cells). Air movement in fiberglass and cellulose significantly diminishes their R value, since the trapped air is displaced by moving air. (Convection can reduce effective R to zero.) Holes in the wall systems, and the vents in an attic allow for air movement. The U.S. Department of Energy estimates that the average home has 2,000 linear feet of cracks and gaps in the envelope, resulting in a loss of 30% of conditioned air (heated or cooled). In addition to holes in outside walls, many traditional insulating companies leave gaps around the fiberglass batts; this plus the sagging and shrinking of batts and cellulose leave areas of zero insulation in wall cavities. You may think you have R 19. You may actually have R 1. Water penetration and condensation reduce the R value of these materials as well. Therefore, the effective R Value of the entire wall or ceiling/roof assembly is often half of the R value printed on the material. Spray foam doesn’t sag, shrink, and fills all holes (when properly applied), and closed cell foam is air impermeable (no convective effect) and water impermeable. So it retains its R value. It’s also more expensive – usually double the cost of fiberglass. But the simple payback is usually measured at about 5 years especially in the colder climate states.

    I hope this clears up my “misstatements” and “technical errors on basic stuff” like R-value measurements, especially for those who are looking at my “claims” with “great skepticism.”

  19. homedesign | | #19

    You are digging the hole deeper
    Robert Smith,
    Martin was right the first time.

  20. GBA Editor
    Martin Holladay | | #20

    Another response to Robert Smith
    You are still misunderstanding heat flow and making misstatements. I suggest that you read the article that John Brooks referred to (see his link).

    You wrote, "The problem is the common misconception that doubling the R equals doubles the insulative value. It doesn’t." Yes it does. Every time you double the R-value, you double the insulative value. You also cut the rate of heat flow in half.

    You wrote, "Air movement in fiberglass and cellulose significantly diminishes their R value." No they don't. The R-value per inch of an insulation material is a material property that is determined in a lab. Air flow may diminish its thermal performance, but it does not diminish its R-value.

    You are right, of course, that "many traditional insulating companies leave gaps around the fiberglass batts." That's why I have been preaching the virtues of airtight construction methods for years. But attention to airtightness is important for all builders, not just those who use fiberglass batts. Builders who insulate with spray foam still have to pay attention to airtight construction methods.

    On average, homes insulated with fiberglass batts are leakier than homes insulated with spray foam. That's a strong argument in favor of spray foam, but it's no excuse for making misstatements about R-value.

  21. Zndnus7Qtw | | #21

    R Value vs Thermal Performance
    Martin, you are right again. I got in a hurry. R value is a laboratory-determined number for perfectly performing materials. It is also what building code is based on. I guess it has to be based on something that consumers can read and get an idea of what they are getting for their money.
    What you called thermal performance is what I was calling insulative performance or value. As you said, and I think we are saying the same thing, actual thermal performance diminishes with thickness and with air movement. R value doesn't change. It's a lab number. When I advise customers, I think U but use R, since that's what they're used to hearing about. I also advise on the performance of materials in field conditions versus carefully controlled laboratory conditions.

    Thanks John for the reference to the other article bashing SPF; I read all of the postings, pro and con. Math is math. More insulation may add more R value, but it reaches a point of diminishing returns, where that extra inch has so little impact of heat transfer that it’s pointless, and certainly not cost-effective to add more – unless you do a hybrid wall system with complementary insulation materials, as I mentioned, and, curiously, no one noted. This is what I advise my customers.

    Back to the point of the original article Martin posted. The implication, obvious from Andrea's question, is that home owners need to be careful that their homes may suddenly burst into flame during construction. It is not merely an issue of SPF thickness, as the article implies. It is applying too much, too fast. SPF goes in at roughly 120 degrees F. If after the first pass, the sprayer doesn’t give the foam a few minutes (literally minutes) to cool and cure, and just keeps pouring on inch after inch, it will get hot enough to smoke and eventually burn. Every certified sprayer is trained not to do this. But even trained people get distracted, get in a hurry, and do stupid things. Did you hear about the master parachutist with 10,000 jumps, who was so concerned with his helmet cam that he jumped out of the plane WITHOUT HIS CHUTE ON? As I said before, an electrician can burn a house down too. In Vermont doesn’t the GC or subcontractor carry mandatory insurance to cover accidents, including burning down a house during construction?

    The fear of SPF fires was reinforced by Sevag Pogharian’s references of polyurethane foam as “solid gasoline.” The “solid gasoline” jargon used in the insurance and fire fighting industries is in direct reference to FURNITURE (although one insurance source has transferred this, word for word, to insulation). Many items of furniture – just about anything you sit or sleep on – have polyurethane foam cushions. These cushions, once they catch fire, do burn intensely and create black smoke, etc. Of course, they don’t have a thermal barrier or an ignition barrier on them like wall insulation does. And foam furniture is not the same chemical formulation as open cell wall insulation, but close. Did you know that both engineered and real wood floors have polyurethane sealant on them too? As well as most cabinets and wooden furniture surfaces? And most OSB and particle board manufacturers once glued together their wood with off-gassing urea formaldehyde; they are changing over to – you guessed it – polyurethane! Folks, it's not just the insulation...

    Presumably, by the time a home’s wall assemblies are burning, and any open cell spray foam in the walls is ignited, the furniture has already combusted. It does take quite a bit of heat to burn through gypboard to get to the foam in the wall cavity (or the attic). So if you’re really afraid of the thick black smoke, etc., you might think about new couches and chairs without cushions first. All of this is to say, if you’re really worried about being asphyxiated or dying in a burning house (after you’ve taken ownership from the builder), then you have a lot more to worry about than combustability of the wall insulation.

    I am a big proponent of closed cell SPF – 2 lb, not ½ lb open cell – for many commercial and residential uses. Closed cell is hard, rigid material, air impermeable, water impermeable, vapor retardant and twice the R Value of fiberglass or cellulose. It will burn at the same temperature and rate as red oak. Your pine studs will go faster. So we shouldn’t confuse closed cell and open cell (2 lb versus 1/2 lb) foam. Just like we shouldn’t assume ALL drywall gives off toxic odors that can kill children.

    Or you could, as Sevan suggested, go back to rock wool insulation. It hasn’t killed anyone. And since automobiles are inherently dangerous, even in highly trained hands, and very combustible (real gasoline as well as seat cushions!), and a really, really big sources of GHGs, you should think about horse-drawn transport. It doesn’t perform as well, but it’s a lot safer, and greener too. :)

  22. NJFoam | | #22

    helpful explanations by Robert Smith
    I am a spray foam installer, and I found this thread to be somewhat balanced in terms of "spray foam bashing" vs. counterpoints of the merits of SPF as an insulating material. I think it's important to look at any product's merits vs. risks. SPF application is in its relative infancy as compared with trades such as framing, electrical, plumbing, etc. ..and I might add that the interest and use of SPF has come about along the same lines as the increased understanding of building science and proper sealing of a structure's envelope. As an installer, some of the points made are "preaching to the choir" in that SPF, like most other trades, is not a job to be handed to the lowest bidder.
    I've personally done blower door tests, taken a close look at home performance, both pre and post SPF application, and I know how it works. We keep seeing the same arguments about R-value, safety, etc., while the fact remains that proper SPF application is essential, and there is a valid point of diminishing returns. I want to point out that those of us who take in the information this site provides are all interested in the same thing.... building performance for responsible living, and I appreciate the comments of those who take an objective look at how best to seal and insulate structures, safely and cost effectively. If you like cellulose, please use it, and please air seal properly to accommodate its use, but if you consider the use of SPF, please seek out a qualified installer using quality products and methods. I carry insurance, as do the electricians, HVAC professionals, carpenters, etc that I work with. I take a responsible approach to what I do, as do other tradesman, and we earn a sustainable living based on offering an option that performs as stated, and we rely on repeat business and referrals. Burning down houses is not good for one's business, or conscience, as is a logical and realistic discussion on the merits and drawbacks of any construction method. I disagree with sensational attention grabbing lines insinuating that SPF will burn one's house down, and I am pleased that there is a forum for discussion to offer sound building advice to professionals and homeowners alike. SPF is a proven product, and I don't intend to incinerate myself or anyone's home. I take pride in the amount of fossil fuel I save every day from being burned and released into the atmosphere. There are costs associated with this, but the bottom line is.... save fuel, save money, save the environment... and SPF is an option for those who take an objective look at the problem of inefficient structures and practice proper product stewardship and application methods. I choose not to enter into the arguments concerning U values vs R values, and offer advice to homeowners based on my professional experience of home performance vs cost. I will add that I own an SPF rig, and I can spray as much foam as I want, for a much lower cost than my customers, and I'm comfortable with my R-28 roof, and R-21 walls, in climate zone 5, safely housing my family, and burning as little fuel as possible. The point of R-values is well taken, but often mute, as the metric that really matters is building performance. Let's compare those numbers instead of theoretical performance based on lab testing. The last point I'll add is that in terms of fire safety, YES, Spray foam is combustible under some conditions, but those conditions almost always exist once all occupants of the structure would be have long since died. Let's take a look at fire safety from a rational angle. ..... and sprayers, please follow the mfr. spec. You can't lay down 8" of closed cell foam in one pass, even if some misunderstanding designer specified this amount, and the GC contracted the install at a below market rate.

  23. homedesign | | #23

    Misunderstanding Designer?
    Steve, where did you find the reference to 8" of foam?

    And exactly what did the designer misunderstand?

  24. UDgrss8Ayz | | #24

    This article is not what I thought it would be about . . .
    As a fireplace installation contractor, I really thought this was going to be about foam insulation installers applying foam to fireplace vents and chimneys, causing overheating and fire. Foam installers are no less or more guilty than other insulation contractors, it is just much more difficult to remove foam than cellulose or fiberglass. Every year, a number of house fires are attributed to insulation being placed too closely to fireplaces or vents in the required airspace clearances.

    I was unaware that the foam application was an exothermic reaction and that there is a danger of misapplication, other than the fact that it gets EVERYWHERE, including places it shouldn't be.

    Thanks for an enlightening discussion. It appears from the previous comments that Foam isn't the solution to world peace, nor is it the anti-christ. We all rely on educated, certified professionals to do their jobs correctly. New technology raises the bar a little bit, but life would be boring if it didn't.

  25. svghG2y3U9 | | #25

    Here's the sentence from the
    Here's the sentence from the Fine Homebuilding e-mail;

    "Several spontaneous house fires in Massachusetts have been linked to improper spray-foam installations."

    That is extremely unclear and misleading, and it isn't cleared up too much by reading the actual article here. It's only when you get in to the comments that the coherent truth comes out. It's getting to where I detest headlines and articles written the way this one was. It's very sloppy (to say the least) when Andrea can ask how long after installation could this happen. It's NOT going to happen after more than 1-2 days after, and ONLY if the foam was applied too thick - which doesn't allow the heat of the chemical reaction to dissipate. We have lived in a polyurathane foam insulated house for 12 years now and I would't consider anything else. The foam contractor was extremely careful to not apply more than two inches of thickness in one pass.

    1) The word spontanous in relation to conbustion only applies to the installation phase, and if the installer sprayed it on so thick the heat the chemical reaction can't dissapate.

    2) As with any thickness of insulation there is a diminishing return (energy savings) with increased thinkness. We used 2" foam/6" fiberglass/1" foamboard in the walls and 4" foam/9" fiberglass in the ceiling.

    3) One capability of foam that's often missed is that it seals air movement. That capability is a stand alone reason to use foam in my opinion. If air movement through walls and ceilings is stopped so is the flow of energy from where you put it and want it to stay. Our house is amazingly easy to heat, the garage on the northside never freezes in North Dakota winters. We have floor heat in the garage but have never turned it on. The unfinished garage walls currently have 1" foam, and 1" pink foamboard.

    It was interesting to build a "hot roof" poly foam insulated house back in 1999, be crucified for it by some on the old taunton press breaktime board, then read subsequent articles in Fine Homebuilding outlining foam contruction breakthoughs that mirrored what we and others did ten years earlier.

  26. Zndnus7Qtw | | #26

    R Value an immutable Lab Number?
    Question for Martin or John. A piece of R-19 fiberglass batt, stapled to a knee wall, now has a thickness of 1/4" at the point of stapling. Is it still R-19 at the point of stapling? This is where I think our discussion diverged earlier. My understanding of fibrous insulation is that the R value is almost enitely based on the trapped air in the material. Once crushed -- by stapling or being jammed into a tight space, the air in the material is reduced. Presumably the resistance to heat transfer is reduced with less air, hence the R value is reduced, right? Physical properties of most materials change when the material condition is altered - crushed, soaked in water, heated, cooled, etc. I assume that fiberglass batts have the same sorts of limitations as other materials.

  27. svghG2y3U9 | | #27

    Our foam contractor applied 2" and allowed it to cure for at least one full day before applying the final 2".

    We have a heat recovery air exchanger.

    Foam adds strength, it can easily double the racking strength of a wall.

  28. svghG2y3U9 | | #28

    Hey Robert Smith, fiberglass
    Hey Robert Smith, fiberglass is best when used as a filtering material. Ha,ha! There can be actual air circulation in wall/ceiling bays insulated with fiberglass because figerglass cannot not stop air movement. Closed cell foam can stop air movement dead. That's a huge difference, and why fiberglass works much better when used with a closed cell insluation like poly foam.

    We used double 2x4 wall construction with one inch between the walls. 2" foam was sprayed on the outside wall encapsulating the studs before the inside wall was built. The resulting open cavities were filled with fiberglass;


  29. XYgQMnyH63 | | #29

    Knowledge is key
    As a former building contractor and current firefighter and fire investigator, I have to chime in here.

    Determining fire cause and origin is a very complex science, and sometimes the best we can do is eliminate other causes and come up with a best guess. The info presented lacks enough scientific facts to be relevant to the building industry, and it is irresponsible for the info to wind up on this forum as an article. It is poorly written, sorely lacking in important details and completely unsubstantiated - I checked with my colleagues in Massachusetts. The fires were NOT blamed on spray foam - recently applied spray foam was present in the fires and could not be ruled out as a cause or contributing factor in the fires. Not enough evidence exists to determine that the fires were indeed caused by the spray foam itself. Incompetent journalism like this cheapens the good work done by the fire officials in Massachusetts and only serves to further incite an endless debate among professional builders. You can redeem yourself by accurately reporting the contents of the fire investigations and their cause and origin determinations AFTER the investigations are completed. Several of the fires cited are still under investigation, meaning no cause has been determined yet. A little bit of research and a healthy dose of basic journalism would make for a far more useful and informative article that the professional builder could use. There has been quite a bit of testing done by professional fire organizations on fire behavior in the presence of spray foam insulation - there is evidence that when properly applied, it can actually slow or stop fire spread in an enclosed wall cavity.

    The best take home message that we can all glean from this article and the ensuing comments can be applied to all aspects of the building industry: if you do not fully understand the products you are installing and how to install them, you are not doing anybody any good. Sloppy contractors kill people and cause property losses. Diligent professionals take the time to do it right. You choose which one to be, or as a homeowner you choose which one to hire.

    Mr. Pogharian's comments are misleading. All common building contents produce thick, black, toxic smoke when lit afire. Flashover is a specific phenomenon associated with rapid fire growth in a confined space, not attributable to a specific product or item. Properly applied spray foam insulation is a proven, perfectly safe product. It is not "solid gasoline", nor does it "flashover" when lit. There is a risk of fire due to improper installation as described by susequent posts, not due to the cured product itself. As for the property being a total loss, fires burn hotter and more destructively today than they did 20 years ago due to several factors, most notably the widespread use of synthetic materials in building contents, the propagation of lightweight building materials and improvements in building insulation practices. These three factors in particular result in hotter fires being held inside the structure for a longer period of time, which causes significant structural damage and greater property loss. These fires are unpredictable, dangerous and difficult to fight. The push to go green comes at a cost - green structures don't survive fires. That's why firefighters promote fire sprinklers - they will put out a fire before you know you have one.
    It has nothing to do with the type on insulation used. If spray foam insulation were so dangerous, it's use would be banned by the fire codes, which were updated last year.

    I see a greater risk in spray foam installation to installers themselves during installation in poorly ventilated spaces because the propellant displaces oxygen, and some propellants are combustible or hazardous to your health. Fires in buildings under construction occur far more frequently due to plumbing torches, oily rags and electrical overloading than due to spray foam. Let's keep some perspective here. The insurance industry does not look down on spray foam. If your carrier does, you should switch carriers - you're being screwed. The insurance industry does like homes with sprinkler systems, though.

  30. Zndnus7Qtw | | #30

    Amen Brother!
    Thank you Sloane for the expert addition from the fire-fighting sector (and building construction) to this thread.

  31. hrNbGskXEM | | #31

    "Solid Gasoline"
    My comment that polyurethane produces "thick, black, toxic smoke when lit afire" is not misleading. It is fact. On the contrary, Sloane's sweeping claim that "all common building contents produce thick, black, toxic smoke when lit afire" is inaccurate and reduces this discussion to a simplistic level. After all, how toxic is Roxul in a fire? One can achieve extremely well-insulated and air-tight walls with rock wool without any of the risks nor the toxicity associated with polyurethane. My conclusion is that the risks associated with polyurethane far outweigh its benefits. As design professionals and builders, we need to take a systems or holistic view of our buildings and not be seduced solely by polyurethane's high R-value.
    Furthermore, regarding polyurethane as "Solid Gasoline," please refer to this article:

  32. Joe_Bob | | #32

    If you're concerned, specify and detail SPF carefully
    Section 316.3 of the 2009 IRC permits foam plastic insulation with surface burning characteristics of up to 75 flame spread and 450 smoke developed. There are plenty of products on the market with FS under 25 and smoke developed under 350. Use them. Likening the product to 'solid gasoline' is nonsense. A material with FS <75 and sd <450 simply doesn't have those physical properties. yes, it's combustible but no moreso than common building contents like carpet or upholstered furniture.

    One important caution about the thermal barrier exception for attics, where an ignition barrier is permitted: The same section of the IRC that describes allowable ignition barriers also has this caveat: The space is entered only for purposes of repairs or maintenance. In other words: no storage.

    If the space is in any way accessible by the homeowner, there will storage in the space, no matter what they're told. Christmas decorations and boxes of old papers will be piled up under the SPF insulation. Thin ignition barriers, like intumescent coatings, will inevitably be damaged as things are moved in and out of the attic space. A safer approach is to not use the code exception, and apply a thermal barrier even in attics and crawlspaces. An unsafe condition can be easily prevented, so don't even give the homeowner the opportunity to create one.

  33. Zndnus7Qtw | | #33

    Sevan's "Article"
    I read the one page "article" from the "loss prevention trainer for Federated Insurance of Canada." I also read a number of other articles and opinions and found that your author had lifted the claims for his hit piece entirely from previous articles detailing the dangers of polyurethane FOAM MATTRESSES AND FURNITURE. As I said before. He didn’t do any research or testing to back up his claims, and transferred fire marshals comments about exposed, untreated furniture to barriered, flame retarded wall insulation. There is a huge difference -- the flame retardant and barriers that wall insulation has.
    As Joseph Ford pointed out, ASTM testing has shown that flame spread and smoke developed indexes for insulating foam are well under other building and home products. As I said before, your furniture will combust long before your walls do. Finally, after making outrageous, UNTESTED, nonsense statements like wall foam causes flashover, your author concluded that builders should follow building code. Well, duh.
    I'll take the advice of a fire fighter and fire inspector (Sloane Valentino) who actually checked with the Massachusetts authorities on the validity of the original article’s claims (and found those nonsense too).

  34. user-1005581 | | #34

    The search for facts...
    This discussion has been intriguing and to some extent enlightening.

    I'm getting ready to embark on the total rebuild of a single-wide manufactured home that was built in 1973 and just 16 miles from where Hurricane Charley made landfall. Basically it will be a new home partially supported by the original metal frame.

    My goals are to make it as strong and hurricane-resistant as possible. I'll be following guidelines for 130 mph wind speeds. My other goal is to eventually have a net-zero-energy home. Both goals mean I need very strong but well-insulated walls. Green and sustainable are also high priorities. Fire safe as well.

    Although not inexpensive, closed-cell spray foam seemed to help meet several goals: strengthen the walls, make them air tight, high R-values. Now that the dust seems to have settled on the discussion here, would anyone like to present facts against the use of spray foam insulation in an objective and non-argumentative way? I do want to state clearly that since I live in a hurricane zone I'm not interested in insulation that won't add additional strength to my structure. If it isn't strong enough, it could easily be blown apart in a hurricane. I have already started addressing fire prevention: all of my breakers are ground-fault, arc-fault combination breakers. I will be installing a sprinkler system. The walls will be 3/4" plywood screwed on the inside and outside of the 2x6 studs and there will be drywall as the final surface on the interior. Oh, financially after losing my home and condo in foreclosures I'm not in a position of being able to buy another home. I'll be doing all of this rebuild myself.

  35. Zndnus7Qtw | | #35

    Univ of Florida wind load testing
    You may already be aware of out these articles about hurricane testsing and SPF.

  36. XYgQMnyH63 | | #36

    Read. Focus. Think. Learn.
    All common building contents do produce thick, black toxic smoke. Synthetic materials and finishing compounds found in beds, furniture, drapes, carpet and wood finishes contain ingredients that produce toxic vapors when heated and deadly black smoke when burning. It is not overly simplistic - quite the contrary. There seems to be a serious gap here between having personally experienced a fire and really understanding the beast.

    The majority of residential fires begin inside the living space and spread from there. Stovetops, electrical appliances and discarded smoking materials on furniture are among the most common causes. Very few fires begin inside walls or attics, which is where we find the insulation, and none of them are spontaneous events in a finished, occupied structure. Improperly insulated or overloaded electrical wiring is a frequent cause of the rare attic or wallspace fire, but these are not common fires by any means. The appliance causing the overload often burns first, setting the interior contents of the home ablaze. By the time an interior fire breaches the drywall or plaster and enters the structural components, all is lost and the matter of wether or not the insulation will burn is a moot point. Lightweight structural components perform extremely poorly in fires, regardless of the burning qualities of the insulation around them.
    I understand that a significant loss occurred and the fire was blamed on the insulation. That is unfortunate, but the arguments that insulation itself is not safe lacks a solid scientific base. People smarter than all of us have done more research than we have and come to a far different, fact based conclusion. If you are scared of the foam or don't like it, don't use it. But don't preach nonsense based on half truths to the rest of us. One bad experience does not make it a bad product.

  37. user-1005581 | | #37

    Thank you Robert for the excellent study "The Use of Closed-Cell Spray Polyurethane Foam (ccSPF) to Enhance the Structural Properties of Wall and Roof Assemblies". That is definitely information that I needed.

    Thank you Sloane for clarifying various aspects of fires in buildings.

  38. hrNbGskXEM | | #38

    Sloane: Here are a few simple questions; try to answer them honestly and concisely. Does rock wool insulation, as an individual building component, produce toxic smoke in a fire? Does it contribute to propagating a fire? Can it cause a fire? The answer, with respect to polyurethane insulation, is affirmative to all three question.
    You state that if I don't like polyurethane I should simply not use it and that by highlighting the inherent flaws of this material, I am preaching nonsense. Your attitude does a disservice to discussion forums such as this. I urge you to approach this matter rationally and without emotionality.

  39. Zndnus7Qtw | | #39

    Building components that burn
    Sevan: I think the nonsense Sloane was referring to was your first post about polyurethane insulation causing flashover and so on, not your correct assertion that it is more combustible than rock wool.
    In your designs, you obviously use rock wool because it's not combustible, and does insulate (though it's not an air barrier, vapor retarder or bulk water barrier like closed cell SPF). But really, this is getting silly. Do you avoid all combustible building components in your designs, or just spray foam insulation? Do you not use wood studs and OSB sheathing? Wood floors? Wood joists? OSB subfloors? Wood cabinetry? Wood molding? Wood rafters and roof deck? Wood stringers and steps on staircases? Since we've already established that closed cell SPF ignites and burns at roughly the same temp and speed as red oak, I'm just trying to figure out what you use in your designs instead of wood? Not to mention carpet and padding, and vinyl, and so on.
    You really can't blame someone who wants to use an advanced, energy-saving and structural material that is no more combustible than the wood framing, and much less combustible than the furniture where, Sloane pointed out, most fires start.
    Just to carry this to its natural extreme, do you design homes with no natural gas appliances, no heating oil, no attached garages, no swimming pools and no stairways? I mean you wouldn't want to risk a natural gas explosion (talk about combustible!), carbon monoxide poisoning, VOCs from the garage, a drowning or a catastrophic stairway fall... Just want to see how risk-averse an architect you really are. :)

  40. XYgQMnyH63 | | #40

    rational without emotion
    Sevag, we are both asking each other to do the same thing, to approach this matter rationally and without emotion. I agree with your points on rock wool insulation not producing toxic smoke and contributing to fire spread. What I am trying to impart here is the idea that once a fire reaches the insulation, its a moot point. By that time the rest of the structure and its contents are on fire and have been for several minutes, producing toxic smoke and contributing to fire spread, regardless of the insulation type or its burning properties. The material used to unsulate a structure, no matter what it is, is not a significant factor in wether or not a house will burn.

    The single greatest producer of toxic smoke is polyurethane, which is present is some form in EVERY habitable space, and used in many common building materials. Wood finishes, carpet, furniture, manufactured wood products, insulation, window coverings and appliances all contain it in some form. Reducing it's presence in the wall cavities might produce less smoke, but it doesn't matter in the overall picture with respect to a structure fire.

    I do see the potential for a fire caused by improper installation. I do not see that potential lasting longer that the foam manufacturer's stated full-cure time, so that risk to a structure drops off rapidly after initial installation. Curing foam is likely more combustible than fully cured foam, adding to that risk. Properly installed and fully cured foam is nothing like "solid gasoline". Flame propagation properties for fully cured foam are safer than many other building materials. That portion of your argument is the nonsense I am referring to. The insurance industry does not refer to polyurethane foam insulation as "solid gasoline". One insurance article did. If the industry considered polyurethane insulation a risk, people with spray foam would be paying higher premiums and there would be a lot of info pouring out of the insurance industry assailing spray foam. The insurance industry and the fire service work together constantly, we have similar goals; to reduce property loss and injuries or deaths to people. If spray foam were dangerous, it would have been an issue during the NFPA code revisions last year, and it wasn't.

    Just to be clear, polyurethane is a common chemical found in nearly everything, and it does burn like hell when heated and it produces thick toxic smoke. To eliminate it in the structure's cavities is a noble goal, but you're probably only eliminating about 10% of the polyurethane in an occupied residence, and not even in high risk areas. If occupant safety is your goal, I recommend reducing the presence of polyurethane in the living space, where is is far more likely to contribute to a fire.

    As pointed out earlier, improperly insulated or overburdened wiring can cause a fire, and if that occurs within a wall cavity it will find something to burn. The type of insulation inside the wall doesn't really matter. Rock wool allows some air movement, so there will be some oxygen for the fire to use as it searches for more fuel. Foam insulation can be raised to a point where is is very combustible and it will support combustion. Whichever insulation you have does not matter - you have an electrical fire in the wall. Unchecked, it will burn the house down.

    I'm going to soapbox it here a little bit: We are probably on the same page here - seeking to reduce risk to life and property - be it for the houses we build and the clients we build them for, or for the communities I serve. If we are to be successful, we need to look at the big picture, not focus on and villify individual components. Polyurethane can be dangerous in the presence of fire, and we will not be able to get rid of it. It is economical, versatile, and everywhere. What we can do is understand the risks and mitigate them where possible. Where we can't, we have to find another way to protect our clients and their property, which is why the fire service is pushing as hard as we are for sprinklers. Spray foam insulation is one of a thousand building products and ideas that have come along in the past 30 years that change how we build structures and what we use to build them. These changes are great for homeowners and the environment, but these newer materials and practices come at a cost. Modern structures and their contents burn hotter, fail sooner and offer less proctection to their occupants during a fire, even with rock wool insulation. As long as humans interact with their environment, there will be fires. We cannot prevent them, but we can make them survivable events and reduce the structural loss.

  41. r2idSHczvd | | #41

    Fact and Fiction on both sides of SPF
    I am chiming in here gentlemen from Canada. I have long dismissed this website as clearly anti-foam in its position. All of the editorial content that is featured here is less then balanced and its distain for the SPF industry is clear. What I do enjoy and love are the posts that get a great dialogue from various perspectives. As a Contractor of SPF, I do not hide my support of the material. For much of the same reasons stated here by other advocates. Thank you to both Robert and Sloane for their insightful comments. Sevag, if I am not mistaken, you were the owner of the home that was lost in Quebec that is referenced in this article. My sincere apologies to you for this unfortunate event. Clearly your project was the victim of poorly installed foam. The fault of the installers and not the material. As I have seen your other posts on other websites it would appear that you have a clear anger against the industry due to your unfortunate experience. And while I understand the motivation for your now negative feelings towards the use of spray foam, you are really not being fair or balanced in your remarks. They are tainted by your own negative experience. In Canada, we install millions of kilograms of spray foam a year. As a member of CUFCA we track our work on daily worksheets that are submitted to our association. We have a great Site Quality Assurance Program that involves site testing, and recording on each and every job. The occurrences of fires directly linked to foam are few and far between and those that do occur, are usually traceable to operator error. I am not saying that this is acceptable. Clearly our industry has to do more to educate installers. But we also need a process aligned with inspectors to get the unqualified people out of the business. As in any industry we will always have issues surrounding competency. There are very good, very competent contractors and there are those that are not. But to discredit all of the good that 2lb. Closed Cell SPF can do due is really not acceptable. Plane crashes are a horrific tragedy, yet we continue to fly. My point simply is that as I continue to read arguments both pro and con we will always find zealots that are not willing to listen to the other's side. We therefore must agree to disagree. Roxul is a great fireproof batt made from Rock. We agree it is less flammable then a thermoset plastic.. But the SPF is not just insulation. It is an integral air and vapor barrier and is structural. So once in a wall assembly installed correctly with thermal barrier is will provide a air tight, mold free, stiff wall for the life of the building. The end of life I hope would be measured in 100 plus years in an average residential home. The carbon reduction achieved from a superior performing building with SPF over a life of 100 years will far outweigh the GWP numbers that will be used by our industry detractors. I would encourage all to see what the US Army thinks about the use of SPF while stationed in IRAQ. Lets agree that the use of foam needs respect and has some installation risks that can be mitigated with due diligence in Contractor selection. But let’s not throw the baby out with the bath water. I think that perceptions can all be changed with education and an openness to learn on both sides. I have seen contractors that are far too confident in the material also. So we have extremists on both sides of the divide. Let’s keep talking and learning.

  42. user-1005581 | | #42

    Facts please...
    In 12 years of research about green building I have experienced one thing over and over: Information about various materials and methods of building often comes from companies and organizations that promote, manufacture, sell or install particular products. Invariably they present a product's good aspects and virtually always fail to mention its less desirable traits. Before I realized this I would embrace a product or building practice readily. Then a few months later I would find other information that tempered my initial opinion.

    Often the problem is that the proponents have a very narrow focus and fail to see and present other aspects of the total picture. Every product, material and building practice has many different traits. I have yet to find one that is totally good in every situation and has no negative traits. There are situations where one is certainly the best choice. But there are other situations where that one is definitely not the best choice. As I see it, in the end it is the responsibility of the home owner to do her/his research and choose what is best in their situation. Granted, this is a very complex undertaking to give an untrained individual, but in the end it is their home and therefore their responsibility. It is a bad development in the U.S. that many are so lazy and irresponsible in that they blindly and naively just accept what someone tells them and then quickly take them to court if something goes awry.

    I live in southwest Florida and the major issues I have to deal with are heat, humidity, high winds from hurricanes, heavy rainfall four months of the year, termites and wood rot. If I lived in New Mexico I would probably only be faced with heat and maybe termites. Reading about how someone builds in New Mexico or Wisconsin is of virtually no value to me in building in Florida. I have to make decisions that are best suited for my situation.

    There are other issues as well. Many have a green mind set and want a home that meets those criteria as well. For example, they will choose or reject a product based on how many greenhouse gases are produced in the manufacturing and installation process. But then perhaps fail to calculate how much greenhouse gas is or isn’t produced by their home during its existence. One example: Concrete. It is mostly a natural product that is made from materials readily available close to the construction site - gravel, sand and water. What is good about concrete? It can last a couple hundred years, is inflammable, doesn’t rot, termites don’t devour it, doesn’t off-gas, air tight and has high thermal mass. What isn’t good? It doesn’t insulate well but insulation can be added easily. And a lot of energy is necessary to produce portland cement and that process produces a lot of carbon dioxide. If that carbon footprint is only calculated for the manufacturing and construction phase, it doesn’t look good. But how different the overall picture is if we consider that the material is impervious to many dangers that shorten the life of other building materials and that it could last 100 or even 200 years. So there are a lot of things that need to be considered in making decisions. Some posts in this discussion have been very narrowly focused on just one issue.

    Although this discussion about spray polyurethane foam was interesting and somewhat informative, it is disappointing the way some things were expressed. Instead of arguing, bickering and personally judging the competency of others, each could have just presented the facts. Why has no one put a chart together with a broad spectrum of test data for the various products that have been mentioned? And don’t just present information about flammability. That is just one small aspect of the product’s total traits.

    If the product has a higher risk of igniting, then OBJECTIVELY present ways to reduce the risk:
    * Do not let the installer spray more than two inches at a time.
    * Personally check the internal temperature of the foam before allowing a second layer to be sprayed.
    * If electrical fires are a risk then only install arc-fault breakers and oversize the wiring to reduce the risk of wires overheating. Educate home owners about the danger of overloading a circuit.
    * Install a sprinkler system.
    * Install smoke detectors in every room.

    This is a complex subject. Narrowly focused attitudes don’t do it justice.

  43. user-1005777 | | #43

    Foam insulation
    34 years ago I was renovating a huge century old farmhouse that had no insulation. My choices were blown in Cellulose, Fiberglas, Rockwool, and Urea Formaldahyde foam. I consulted my Father who was the chief inspector for an insurance company. His input was that there were some "rumblings" of problems with Urea foam. I went with Rockwool. As fire chief of the local volunteer fire department I was called to a fire in a house that was insulated with the foam. The fire was not caused by the foam, but we could not get near the fire without OBA gear.

    Having said that, I am thinking that 2 lb foam is a great way to seal and insulate a new home. The added stiffness added to the structure is a plus. I would use at least 5/8" fire rated drywall over the foam. I realise that my couch will kill me before the drywall burns through, but it is for the same reason I would never use metal floor joists. They will fail before a wood joist burns through. The idea is to give yourself the best chance of exiting the structure before it fails.

    I really like the idea of a concrete wall, insulated on the outside with parged foam. The concrete as a heat sink to stabilise the temperature of the house, and the foam to keep the concrete isolated from exterior extremes.

  44. user-1004357 | | #44

    free foam education courses
    My name is robert and I'm the northeast sales manager for a large foam manufacturer. You can reach me at 860-933-7076. Our company offers AIA as well as educational spray foam presentations at no charge. If after reading all of the articles you're unclear or uncertain on any aspect of spray foam please feel free to contact me.

  45. GBA Editor
    Martin Holladay | | #45

    The Journal of Light Construction reports on this story
    The latest issue of JLC includes a story on this issue. Read it here:
    Massachusetts Fire Officials Urge Caution With Spray Foam.

  46. ohioandy | | #46

    the story revisited in a dramatically ironic way...
    [I wonder if anyone will see this addition to the thread, three years later.]

    It happened again: a fire consumes a house, and the fire marshal blames spontaneously combusting foam:

    Only this time, it's the 13,000 square foot mansion of Larry Janesky, he of great renown in the crawlspace-fixing industry and owner of, among other things, the Dr. Energy Saver chain. His article in FHB is referred to here:

    Sadly, it's more negative and knee-jerk publicity for the retrofit industry.

    As an aside: THIRTEEN THOUSAND square feet? It is not often stated on this site, but I will always argue that the SUREST energy saver is downsizing or building small in the first place. The doctor must not have that one in his bag.

  47. GBA Editor
    Martin Holladay | | #47

    Response to Andy Chappell-Dick
    Thanks very much for the link. GBA's news editor, Scott Gibson, will look into the story.

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