Should spray polyurethane foam be installed in an occupied house? Hundreds of spray foam contractors around the country are happy to answer “Yes!” In almost all cases, these jobs end successfully: the spray foam improves the home’s thermal performance and the homeowner is happy.
However, a small number of these jobs go seriously awry. Although each story varies somewhat, reports of bad spray foam jobs have many recurring themes. In most cases, the foam installer made an error: either the foam was installed too thickly or the chemicals were not heated to the correct temperature before they were sprayed. In most cases, the insulation contractor failed to ventilate the job site with a fan during or after the installation. In some cases, areas of foam remained gummy or damp. The biggest common complaint, however, is a bad odor, usually described as a fish-like odor, that lasts for months and is almost impossible to get rid of.
Even do-it-yourself two-component spray-foam kits occasionally produce smelly foam, according to a report by Larry Burks and Jill Burks of Cambridge, N.Y.
Spray foam manufacturers concede that some foam jobs result in smelly foam. I asked Mac Sheldon, Western region manager for Demilec foam, how many spray foam jobs result in odor complaints. “When we looked at the numbers, it appears to be less than one tenth of one percent,” he told me. “While that is not acceptable, we’re working diligently to try and get a handle on the root cause.”
Some manufacturers have responded promptly to odor complaints, and done everything necessary to satisfy the homeowners. Other manufacturers have reportedly brushed off questions from homeowners and referred complaints to the contractor who installed the foam. Finally, some manufacturers have acquired a reputation for doing everything they can to avoid responsibility for odor problems.
Here are stories from eight homeowners, followed by responses and recommendations from a few spray-foam manufacturers and industry experts.
Heather Abello’s story
Heather and Tom Abello bought a recycled timber-frame building and had it relocated to their property in Edgecomb, Maine. The Abellos then hired a contractor to renovate the former barn and transform it into a residence. As part of that renovation, insulation contractors installed Bayer closed-cell spray foam in the walls and ceiling of the building.
According to Heather, her builder noticed a lingering odor which persisted even after the house was drywalled. “He told me, ‘I have been noticing an odor for a while.’ Our insulation installers said, ‘We noticed the smell as well.’
“Bayer paid for all of the sheetrock to be removed and all of the spray foam to be removed. The Bayer rep called me and listened to my side of the story. They said, ‘Don’t worry. We want you to be happy. This is unacceptable.’
“The foam was removed with crowbars. The workers put it in big bags and vacuumed it up. They didn’t get all of it — maybe they got 95% of it. The insulation installers came back and installed a different product — another closed-cell spray foam. Then the sheetrock guy had to come back. Bayer paid for the work. The contractors handled it so well — they were proactive. We are pleased with the outcome — we don’t have any issues now.”
Eric Pfau’s story
Eric Pfau, a structural engineer in Portland, Oregon, hired an insulation contractor to install 4 inches of Demilec open-cell spray foam on the underside of his attic roof sheathing. He and his family were living in the home at the time.
Pfau told me, “When they were installing the foam, they didn’t take any measures to pull the air out of the attic and ventilate to the outside. The guys were in full suits. There was a residual smell upstairs for several months afterwards.
“My wife was pregnant and I didn’t let her go upstairs. I did a lot of studying upstairs, studying for an exam, and it made me lightheaded to hang out up there. Eventually I got worried enough that I had the contractor come back. They brought a big fan, an industrial fan with ducts to create negative pressure. They sucked the air out and discharged it through and upstairs window. The fan ran for off and on for a week or two. It got to the point where it created so much negative pressure it was drawing fumes out of my furnace into the basement.
“After ventilating with the fan, it’s better. There was an issue there, but I think it has improved. I’m satisfied. I have friends over, and ask them if it smells funny, and they say that it smells like an attic. After running the fan, it was like night and day. I put my head up in the attic a few hours after the fan started operating, and 80% of what I was smelling was eliminated.”
David Posada’s story
David Posada, an architectural designer in Portland, Oregon, had Demilec open-cell spray foam installed in his own house. Posada told me, “We were living in the house at the time, but we stayed somewhere else for three or four nights after the foam was installed.
“When we came home after three or four nights, there was a very strong odor in the house, especially on the second floor. The odor seemed to be coming from the access hatch to the attic and some drawers connecting the indoors with the attic crawl space.
“We kept a box fan in the window of the upstairs bathroom. We kept that running and we kept the window in the bedroom open. We continued to do that for two months. Every night we slept with the window fan in the bathroom to create a negative pressure, and we slept with our bedroom window cracked open.
“I had mentioned the odor to the GC, and his response was ‘Yeah, that’s why I prefer cellulose.’ The spray foam contractor said, ‘That’s surprising. It should clear up soon.’ So I contacted Demilec. They initially they were very responsive. They said they would bring filters and fans, but there was a series of delays and they never got the fans and filters installed.
“Even six months later there was a strong smell in the attic, but it was no longer as noticeable in the living space. Now there is a faint chemical smell in the attic. I guess I am disappointed. But the current situation is acceptable.”
Mike Roth’s story
Michael and Joan Roth of Kissimmee, Florida hired an insulation contractor to install Demilec Sealection 500 open-cell spray foam on the underside of the roof sheathing of their home. They were living in the house at the time.
Mike told me, “The contractors didn’t advise us to leave the house, and they didn’t ventilate the attic. Within an hour, my wife got dizzy and her eyes were burning, so she left with our son. I stayed in the house, but an hour and a half later I couldn’t think straight, and I was forced to leave the house as well. I laid down in the back yard for an hour or so. At the end of the day, the contractors were done. My wife returned and said, ‘We can’t stay in this house.’ We both had headaches. We said, ‘This is terrible.’ We stayed with some friends.
“I had no idea what we were getting into. The stuff was very powerful. We came back the next day, but we realized we couldn’t stay in the house, so we brought an RV onto our property where we stayed for six months.
“We’ve had a lengthy ordeal with representatives from Demilec. Their agenda was to prove there was something else in the house causing the smell and it wasn’t their problem. I had a powerful fan in the attic that I had been running for weeks by the time the Demilec rep got there. They brought in another powerful fan. The windows and doors of the house were open for 24 hours a day.
“Demilec has a corporate mentality. They have to try to blame something else. Eventually Robert Naini from Demilec said, ‘Demilec has no liability — you have to go to your installer.’ The installer said he was not going to give us any money, and his insurance wouldn’t cover it.
“The attic stinks like a load of dead fish, and they aren’t going to do anything. Finally I decided I had to remove the roof sheathing and the foam, working from above. We’ve spent tens of thousands of dollars of our own money to remove the foam. We had them hand-scrape the trusses and the gable and the drywall. I would say we got 98.5% of it out, if I had to guess. All of our symptoms went away with the foam. Our son’s breathing improved, and my wife and I are fine now.”
Keri Rimel’s story
Keri Rimel built a new home in Austin, Texas. The walls and attic were sprayed with Demilec Sealection 500 open-cell spray foam. Rimel told me, “The contractor, Deruiter Insulation, didn’t keep us out of the house at all. Our children were there when they were shooting it. We were visiting the job site, and we had meetings in the bedroom as the guy in a haz-mat suit was spraying. The Demilec rep was there on the job that day — Darren Butler from Demilec. He made a surprise visit just to tell us how great the insulation was, and how great Deruiter Insulation was. They did not ventilate at all. In fact all the windows were taped shut to keep the house warm for the next two weeks.
“Three days after they sprayed, my husband’s respiratory system shut down — his throat closed up. I thought, ‘We have a problem.’ Kurt Deruiter never opened up the house at all. We called him up and said it smelled. He said, ‘Just air it out.’ So we opened the windows.
“As it got warmer, the smell would increase. When Demilec came down — Darren Butler and another guy from Demilec — they said, ‘We don’t smell anything,’ and left. Then Robert Naini from Demilec made an appearance. He came out and said, ‘It smells like new paint.’ And my husband said, ‘There is no paint in there — just foam.’
“They said, ‘Ventilate.’ So they set up a negative ventilation system for a month or two. But you can still smell it before you get in the house. We asked, ‘How long should we ventilate?’ and they said, ‘Just keep ventilating.’ Finally Deruiter came to the house and took away his fans. Demilec said, ‘I think we can agree to remove the foam.’ They were about to settle with us, then Fox News broadcast that report about the Roths in Florida, so Demilec came back to us and said, ‘We are not going to help you.’”
Brian Hanks’s story
Brian Hanks lives in a suburb of Dallas, Texas. He hired a contractor to install 5 or 6 inches of Demilec Sealection 500 open-cell spray foam on the underside of the roof sheathing in his attic. Hanks told me, “The first thing we noticed was a strong, pungent odor. It lingered for a long time and made it difficult to breathe. It was almost unbearable to be in the home.
“I called the installer immediately. They said the smell was not harmful and the smell would go away in a few days at most. I asked, ‘Do I need ventilation?’ They said, ‘No, don’t worry. It’s not necessary.’
“After some strong urging, the installer eventually came by the house. After further coaxing, they brought a HEPA filter which circulated the air in a circle in the attic — just pulled in the attic air, filtered it, and discharged into the attic. This failed to do anything useful, so I installed my own fans at my own expense, one being a manhole blower with 8-inch ducts. I ran the ducts into the attic, through a stairway and an attic access hatch. The intake side was pulling air out of the attics and exhausting it out of the adjacent windows. I ran the fans for a couple of weeks, and in the cold winter weather the house seemed tolerable, but the odor persisted.
“Then I called the manufacturer. I spoke to a lady at Demilec, and she assured me the odor wasn’t a problem and that it wasn’t harmful. Then the weather got warm. It was hot outside, and the south sun was hitting the attic. The smell came back and we all got sick — constant, recurrent colds and lung problems.
“The general pattern has been that the odor and symptoms are tolerable in the wintertime, but in summertime when the hot Texas sun hits the roof, it is awful. At that point I contacted Demilec, but they were very reluctant to admit there was any issue. After I provided much encouragement, they eventually sent someone over to the house, although they did not agree that there was an odor. This was back in the summer of 2010, approximately 18 months after the initial install. Demilec came over and said they would spray something that would take care of the problem. They sprayed a mist in my attic and told me to stay out of the house for a day. I saw the container name and did some research — they sprayed a glycol-ether-based deodorizer.
“Immediately following the application of the deodorizer, my entire family lost their ability to taste, and being in the house became even more unbearable. After several more visits, IAQ tests, blower door tests, and several months, they suggested that I convert the attic back to a vented attic. I did part of the work on my own dime. They removed the foam at the perimeter of the attic, and sprayed more foam on the attic floor to seal the living space. This was in the winter of 2010.
“When the heat of summer returned, so did the odor and irritation. I installed powered attic ventilators in the roof, solar powered mushroom vents, and things got better. Even with all of these steps to mitigate, in the summer the smell was back. It was unbearable again. I had Demilec come back and they ran more IAQ tests and a bulk foam sample. They found significant levels of dimethylhexane, propane, and butane compounds in the air. Yet the bulk foam sample did not test as a source of those compounds. I then pointed out that the foam had been sprayed on four different occasions and asked for more testing.
“Yesterday, they were out to the house again to collect more foam samples. They seem to be continuing to deny that the foam has anything to do with it. They aren’t offering me a thing.
“Not a single contractor I have found will take the foam out. None of them have experience with removal, and they all warn of the dangers of polyurethane dust. At this point, my energy bills are as high as they were originally, my family has suffered through 2 1/2 years of chemical exposure, and I’ve spent countless hours and tens of thousands of dollars on HVAC improvements, ERV installation, dehumidifier installation, sealing attic penetrations, and attic system repairs from collateral damage.”
Joseph Dobbs’s story
Joseph Dobbs is a retired engineer in Rock Hill, South Carolina. He hired a contractor to install BASF Spraytite 178 closed-cell spray foam in his garage ceiling under his bonus room. Dobbs told me, “The odor was coming form it after it was sprayed. The man said to wait a few days — just a few days. We waited for several months.
“Finally I contacted him again, and he decided to remove 60% of the foam. He removed 100% of the foam depth from about 60% of the ceiling. Some of the material was installed 7 inches thick in just one pass. He removed the smelly stuffy. They re-sprayed with a thinner layer — maybe at most 3 inches.
“There is still a smell coming from there. It got better, but we could still smell it. I have a neighbor and grandchildren who can definitely still smell it.
“I called up BASF and spoke to a customer service rep, but they didn’t want to help. One of the comments was, ‘We just sell the raw materials.’ I got very poor response from BASF. I asked them out to come out and look at the site, and they said, ‘Sorry, we can’t come out.’
“This odor, this fish smell, is probably, in my opinion, formed by an amine. People say that the odor will go away. But this is a solid that is generating the odor, not a liquid or a gas. It’s like naphthalene moth balls — it’s a solid. Moth balls generate vapor for a long time because it is a solid.
“It takes a long time for the odor to go away. Maybe it will never go away. I think it is a defective product that should not be used. If this product had been put in the house instead of my garage, the house would have been destroyed.”
Bryan Kolodziej’s story
Bryan Kolodziej, a computer systems administrator in Upland, California, hired a contractor to install BASF Comfort Foam, a closed-cell spray foam, in his kitchen ceiling as part of a kitchen remodel. He was not living in the house at the time.
Kolodziej told me, “It is a vaulted cathedral ceiling. On the day they sprayed it, the odor was amazingly bad. Two guys were doing the work. I opened up all the windows in the house and installed fans. The bulk of the fumes dissipated in about a day.
“Very shortly thereafter I noticed a lingering odor that smelled like rotting fish, an amine-like odor. The odor was not dissipating. I contacted them to ask about it, and they just told me to wait it out.
“I set up a complicated system of fans running 24 hours a day to try to air it out, and it just never went away. I ran the fans for about two weeks. I finally called the contractor and said, ‘The smell is not going away.’ They finally realized that they must have done something wrong. They said, ‘We’ll need to come out and re-spray some things.’
“I called BASF and they were very quick to wash their hands of the situation. They knew all about what I was talking about, and they said the foam had been oversprayed. They are supposed to spray a maximum pass of 1 1/2 or 2 inches, or else the heat in the foam from the chemical reaction can cause a burn or degradation, generating this amine odor.
“So the contractor came back. They tried to dig out the bad foam, and they sprayed some more insulation on top to try to seal it. They generated a huge amount of waste. They only removed the bad foam from certain areas. They took about 15% or 20% of the foam out.
“That stuff is not easy to remove. They used a tile scraper — a blade on the end of a handle. The guy who allocated the spray jobs was perturbed about having to send someone back. The guy who did the spraying was complaining about having to go out. They knew they lost money on the job and so they weren’t interested about coming back.
“I was worried about the Romex in the ceiling, because they were chiseling the foam out. I refused to let them chisel in certain areas, and even so he did hit one of my phone lines. He said, ‘We got all of the bad foam out. See, it smells bad, and it feels like a wet sponge.’ Then they sprayed again. Even after they re-sprayed, the odor was still there, but I was afraid to have them come back because they were so angry when they came back the first time.
“Our dream kitchen smelled constantly of fish. I couldn’t walk in the room because the ceiling was so bad. I finally went up there with an oscillating saw, I poked through things and found more bad foam and pulled it out. I had to go all the way and scrape it out. I refilled the gaps with cans of foam.
“Every step reduced the odor some. I got it down as far as I could, and I hoped that the drywall ceiling would seal it. The drywall guys could still smell it. I told them to get the drywall up tight and seal it well. The odor is not detectable now in the kitchen, but you can still smell it in the attic.
“Both BASF and the contractor assured me that the smell would eventually bake out. I know that I would never use that product again — BASF Comfort Foam. I would not use it. I recommend that people turn and run away from it. When I called the contractor, they said that one of the regional reps will call you, but no one every called me.
“What it came down to is they did the job wrong, and they chiseled out as little of it as they could get away with. I called the guys at BASF. He told me what a good product it is. I said, what happens when you get a fishlike odor? He said, ‘That problem is between you and the contractor.’ I am on the verge of carving every last bit of foam myself and reinsulating with rigid foam sheets.”
What’s causing the odor?
By now, most spray-foam experts know that lingering odors can be a problem with some spray foam jobs. According to Mason Knowles, a spray foam expert and consultant in Reston, Virginia, “The odors are coming from a catalyst in the foam, or from foam that is off-ratio or not mixed well or sprayed too thickly.”
According to Michael Sievers, the business manager for BASF spray foam, “The odor that might occur with the foam application is typically caused by one of two things: 1) the contractor applies the foam in greater than a 2-inch pass, or 2) the contractors applies a second pass over the first without allowing the first pass to dissipate the heat and properly cure.”
According to Mac Sheldon of Demilec, “The odor happens when the foam is slightly underprocessed. We call it cold foam. It happens when the recommended application temperatures aren’t followed. The recommended temperature varies with the substrate and the weather conditions. For example, let’s say the recommended application temperature at a job is 140 degrees — that’s the temperature of the product leaving the gun. If it were sprayed at 125 degrees, we wouldn’t get a full reaction. So the catalyst, the amine catalyst, won’t fully react with the A side and B side products, and therefore it won’t be fully consumed. That’s what we are experiencing. Amine catalyst has a strong odor. It is real stinky.”
Almost everyone interviewed for this story agreed that the most likely cause of smelly foam is installer error. Among the errors mentioned: installing foam at too low a temperature, installing foam too thickly in a single pass, and failure to ventilate when the foam was installed.
It’s important to ventilate the job site
Most manufacturers recommend that a spray-foam work site be isolated with polyethylene barriers and depressurized with an exhaust fan while the foam is being sprayed. This requirement for job-site ventilation is described and illustrated in an online best-practice guide, Health and Safety Product Stewardship Workbook for High-Pressure Application of Spray Polyurethane Foam. The Workbook notes, “Having a negative pressure in a contained work zone will draw in air from small cracks and gaps around the workspace boundary and exhaust the work zone air. Active ventilation is achieved by using one or more fans to draw air to or from the workspace and create a negative pressure inside the workspace. Give careful consideration to the location of the exhaust. Ideally, exhaust is released to an unoccupied space where it is not likely to be drawn through an air intake. This will help protect occupants and workers in adjacent areas from potential chemical exposure.” (The Workbook can be downloaded from www.spraypolyurethane.org.)
Many of the homeowners interviewed for this story noted that their spray-foam contractors never set up any ventilation equipment.
Getting rid of the smell
Some manufacturers’ reps believe that smelly foam problems can be solved by ventilating the smelly areas. According to Mac Sheldon, “There’s a finite amount of the catalyst, and if it is gets to the surface and is ventilated out, it is gone forever.” When I told Sheldon that in some cases, the odor persists for months or even years, he answered, “I would not doubt that, especially if there is a dead air space. To enhance the release, we have found that heat and ventilation will help to move it out of the foam.”
Most experts, however, advise that the only way to solve these problems is to remove the bad foam from the house. “I would not consider ongoing ventilation of the house a cure for lingering odors,” said Mason Knowles. “I’ve yet to see a problem that wasn’t fixed by removing the foam. But sometimes you can’t find the section of foam that is causing the odor, so there are cases where you have to remove all the foam.” Although some contractors are worried that there is no established protocol for the remediation of a home with bad foam — do you have to get every last speck? Does the odor linger in the framing lumber? — Knowles believes that bad foam can be successfully removed. “You can remove closed-cell foam,” Knowles told me. “It’s not easy, but you can do it.”
Smells can migrate into framing lumber
Even foam removal may not solve a problem with a persistent odor, however. “We think the smell can migrate to the framing lumber,” Sheldon told me. “We believe it can migrate to other porous materials.” I asked Sheldon whether Demilec had ever agreed to pay for the removal of smelly foam. Sheldon replied, “When they tell you, ‘The Demilec rep was here,’ was it really the Demilec rep?”
I answered, “Most of the homeowners are specific. They don’t say, ‘The Demilec rep was here.’ They say, ‘Robert Naini was here.’” At that point, Sheldon’s tone changed. “Well, if Robert is involved, then there probably has been testing, and Demilec has reached out.” I asked again, “Has Demilec ever offered to pay for the foam to be removed?” Sheldon answered, “I know that Robert has offered — not to remove the foam, but to help ventilate and help remediate.”
Has your installer been properly trained?
Knowles advises any builder or homeowner thinking of hiring a spray foam contractor to find out as much as possible about their training, their certification, and their experience level. “For 7 or 8 years, when the spray-foam business was increasing at a fast clip, some contractors weren’t getting adequate training,” said Knowles. “But now there is better training and better contractor certification.” Knowles provides more useful advice on this issue in an article he wrote for the Journal of Light Construction.
Paul Duffy, the vice president of engineering for Icynene, advises anyone considering the use of spray foam in an existing house to hire a home-performance specialist. “For a retrofit job, we recommend that you have a HERS rater involved, or a BPI-trained professional — someone who understands the house as a system,” said Duffy. “A spray foam contractor doesn’t necessarily have all of those understandings on the same level. … It goes beyond the skill set of insulators generally; it goes into the skill set of a building science professional.”
Mac Sheldon also mentioned the importance of training. “Training is a huge issue in our industry,” he told me. “We have a basic training, and this topic and the procedures for proper processing are covered in depth. We have bridge training for people who have been to our competitors’ training, where this topic is covered in depth. We believe that some installers either don’t pay attention to the requirements or they haven’t been through the training — maybe their boss has been to the training but they haven’t been. We are training over 100 people a month. We are begging people to come to our training. These problems are mostly installer error.”
In addition to verifying the training credentials of your spray foam contractor, you should insist that your contractor isolate the work area and set up a fan to depressurize the room where foam is being sprayed.
Following best practice recommendations raises the cost of the job
Although Knowles is confident that these smelly foam problems are a small bump in an otherwise smooth road, other consultants aren’t so sure.
According to Bernard Bloom, a certified IAQ professional in Silver Spring, Maryland, “The industry has an almost impossible problem inherent in their dependence on spray contractors who have to comply fully with all installation instructions each and every time. For instance, they may have to spray to a certain thickness, wait, and continue spraying. Contractors may or may not follow such instructions to the letter. The industry’s own guidelines call for exhaust ventilation in occupied homes, but this practice is widely ignored. I’ve seen people who sprayed on wet surfaces. My point is that if the spray contractors truly had to work within all manufacturer instructions and industry guidelines, it would up-price the job. There’s a guy at the SPFA who says, ‘You don’t have any information off-gassed chemicals are toxic.’ But he’s ignoring the fact that you can’t live in your house if it stinks or may render you chemically sensitive.”
According to Sheldon, spray-foam manufacturers are working on developing new chemical formulas that will reduce the chance of producing smelly foam. “We’re working on the issue,” Sheldon told me. “We are working diligently in our lab at the basic chemistry level to find improved systems. We’re working on this and other physical properties. Within the next year, I predict — the next year to 18 months — I think the landscape of the spray foam industry will be changed for the better.”
When problems aren’t resolved quickly, homeowners get frustrated
Any experienced builder knows that building materials are occasionally defective. A builder who gets a bad window or a bad sink wants to be able to call up a manufacturer’s rep and have that rep show up at the job site and resolve the problem quickly. If this happens, the builder becomes a loyal customer. In fact, most builders’ choice of window brand is based not on the window quality but on the service provided by their local rep.
By this standard, many spray foam manufacturers are failing dismally. There are a few exceptions; Heather Abello was pleased that Bayer stepped up to the plate and agreed to pay for the removal of all the drywall in her home, as well as the removal of all of the spray foam, the reinstallation of new foam, and the installation of new drywall — all at no expense to her. However, many homeowners report that manufacturers have ignored their phone calls or tried to blame other substances (such as paint) for the odors in their homes.
When I contacted BASF about reports from Bryan Kolodziej and Jospeh Dobbs — homeowners who say that their phone calls to BASF were brushed off — a BASF spokesperson, Michael Sievers, replied, “BASF has been very up front and proactive with respect to working with homeowners and contractors to resolve any questions or concerns they have with respect to our product.” Sievers cited BASF’s response to a complaint from another homeowner, Marty Donnelly, noting that Donnelly posted the following comment on the GBA website: “I would like to add that the manufacturer and the insulators have been very helpful.” However, Sievers didn’t quote this part of Donnelly’s post: “They went into my attic and did a sniff test. They deemed the attic and home to be free of the fish odor. We disagree. There is still a faint odor that drifts into the garage and living area, especially when it is hot.”
According to manufacturers, the odors may be coming from something else
When I asked Sheldon about reports that Demilec representatives have blamed other substances for these odors, he didn’t deny it. “When we have done indoor air quality sampling, we have found high concentrations of substances like formaldehyde,” he told me. “At one job, I observed solvent products stored in a garage area. At some of these jobs, the complaints are consistent with formaldehyde. At one house, the odor wasn’t really strong. We went in with a certified industrial hygienist, and the result of the test showed extremely high formaldehyde concentrations in the kitchen. In that case we offered to install a ventilation system, and the customer didn’t want it.”
Like Mac Sheldon, Paul Duffy of Icynene believes that some of these odors come from substances other than spray foam. “If you are air sealing a building, you have to be mindful of the potential for indoor air pollutants that were previously not recognized now being noticed because of the lower ventilation rate,” Duffy told me. “We have always emphasized the need to ‘build it tight and ventilate it right.’ Ventilation is a huge part of the energy-efficiency puzzle. … In an existing house, the installer may be applying the product on contaminated surfaces. In some case, perhaps the attic used to exist outside of the building envelope, and who know what was up there — squirrels, feces, urine — and now you’re bringing that environment into the living space.”
According to Mason Knowles, “Some suppliers think, ‘It’s another misapplication — why are they calling me in?’ At the same time, you want to provide goodwill. Each company will take their own legal advice as to how they go about it.”
My advice to spray-foam manufacturers is simple: it’s not acceptable to brush off customers with smelly foam. If these cases aren’t quickly resolved, the dead-fish smell is likely to taint the entire industry.
Last week’s blog: “Installing Mineral Wool Insulation Over Exterior Wall Sheathing.”