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Serious Problems With Spray Foam Insulation Used In Homes

Spray foam insulation being applied Credit: Wikipedia

For years I've been concerned about spray foam insulation that is blown into attics and walls. Yes, it is promoted on popular home renovation shows. But what is not discussed is that the chemicals in the foam would be outgassing for years and the occupants of the home would be breathing it in.

Finally, I'm starting to see concerns raised by others - not just harmful health effects from the chemicals, including flame retardants, but also harms to the house itself. It turns out the industry is hiding the harms.... (why doesn't that surprise me?)

Excerpts from an article by Alden Wicker from VTDigger (an independent Vermont news website that publishes watchdog reports): 'I wanted to cry': Devastating risks of spray foam insulation hidden from Vermont homeowners

Londonderry contractor Abe Crossman was keeping busy with small projects at his family’s home in June 2020 during the newly arrived coronavirus pandemic. He was working outside when he noticed that the paint was peeling off the trim at the peak of the gable end of his roof. 

With 25 years of building experience, he knew that peeling paint indicated the presence of moisture. But the location was odd — that trim underneath the overhang should stay dry. So he grabbed a ladder and a pry bar to take a closer look. 

His stomach dropped as he sank the pry bar into the soft wood sheathing underneath the trim and peeled away the vinyl siding down to four feet below the roof line. What had been wood disintegrated into dust in front of his eyes, he later recalled, leaving behind nothing but spray polyurethane foam insulation.

At first, Crossman thought he might have a roof leak. But he found no issues with the standing seam roof. In any case, he said, when a contractor had installed spray foam insulation in his roof and second-floor walls a decade earlier, he had been promised that the type of foam used, open cell, would let water come through in case of a leak, so he should have noticed it immediately. 

He headed inside to his daughter’s bedroom, cut a square out of the ceiling’s sheetrock and hacked at the spray foam so he could see the structure underneath it. He grasped a rafter, and it crumbled in his hand. The roof had dry-rotted. 

“I was in shock and disbelief,” he told me this past winter. “I wanted to cry, honestly.” He was starting to wonder if the spray foam itself might be the problem. 

The big spray foam push

While there are many types of insulation — cellulose, mineral wool, foam board and batting — the spray foam industry has benefitted mightily from this green weatherization push, since spray foam is such a terrific insulator and can be easily installed in one day without tearing out walls. 

Instead, during what would become a year-long journey, I found myself in a thicket of contradictory, outdated or biased information. Plenty of horror stories lurked in forums and blogs: historical homes ruined, fishy smells, moisture problems and people falling ill

Americans — and Vermonters in particular — are especially vulnerable to the risks of poor spray foam installation. In Canada, spray foam installers must be third-party certified. In the U.S., there are no legally-required training, educational or certification requirements for spray foam installers at the federal or state level. 

The result is a Wild West of spray foam installation, raising questions about the long-term damage to homes and ruinous costs to homeowners who are just trying to do the right thing.

Onsite chemistry 

Polyurethane, also known as PU, was invented in Nazi Germany in 1937 by Dr. Otto Bayer, who discovered mixing isocyanates and polyol would create a special type of plastic. One of its first uses was for mustard-gas-resistant garments. After the war, manufacturers found other uses for it in an expanding range of consumer products, including fake leather, mattresses and foam insulation panels. 

In the 1960s, the spray foam gun was invented, which allowed polyurethane foam to be sprayed to fit perfectly into any wall or ceiling cavity that needed an airtight seal — at the time, mainly industrial sites. The 1970s energy crisis, which drove the price of heating oil sky-high, made homeowners receptive to this new, super-insulating product. 

But it was the Canadian spray foam manufacturer Icynene, founded in 1986, which pushed spray foam deep into the consumer market. The company sold its product to a network of independent contractors across North America, who in turn pitched it to homeowners as an easy and effective way to save on energy costs. 

The most common spaces where spray foam is applied are inside walls, under the roof, inside attics, and on the walls of basements and cellars. Contractors often use it for tight spaces instead of using thicker types of insulation, in order to more easily fulfill building code requirements. 

The installation process releases toxic fumes, which is why spray foam technicians must wear a full protective suit and respirator. The foam spends the next day “curing,” or drying and hardening, during which time homeowners must vacate the property. 

If all goes well, the spray foam is inert and done off-gassing by the time the homeowners are back inside. And it has fitted neatly into every space in which it was applied, with no holes or cracks, creating an airtight seal and a deliciously warm home — if everything goes right.

Several building science and material experts, however, say there are many ways spray foam application can go wrong. 

“The conditions where the manufacturers say that you should be mixing and installing this site-created insulation are very strict and almost never met in the field,” said Chris West, a Jericho-based certified consultant and trainer for Passive House, a design standard for ultra-low-energy-consumption homes. “It's like, 80 degrees, and no dust and the perfect humidity of the material you're spraying against.”

Although the U.S. Environmental Protection Agency says that more research is needed, it found that if the chemical mixture or temperature is wrong, it can fail to cure and may continue off-gassing amines, isocyanates and other chemical fumes. In 2013, the Canadian Broadcasting Corporation reported on homeowners who had to abandon their home after it was insulated with spray foam because it made them so sick. Around the same time in the U.S., an “avalanche” of similar health complaints and court cases cropped up against spray foam manufacturers. 

According to 2013 testimony to the General Law Committee of Connecticut from a homeowner, the spray foam installed in his 1890s home shrunk, cracked, gave off a strong noxious odor and even exploded in the middle of the night. He was never warned about the health effects, even while his family lived in the house during remediation, when spray foam dust filled his home. 

Once people are exposed to a high amount of isocyanates, they may become sensitized, meaning even a tiny bit of exposure — like walking into a building with spray foam insulation or buying a memory foam mattress — could trigger asthma. This is particularly a problem for spray foam installers. 

Isocyanates have been reported to be a leading attributable chemical cause of asthma in the workplace,” the EPA warns. “Even if you do not become sensitized to isocyanates, they may still irritate your skin and lungs, and many years of exposure may lead to permanent lung damage and respiratory problems.” 

While failures to cure are immediately apparent, another danger that only presents itself many years later is that the spray foam doesn’t actually create the airtight seal promised, which can lead to air quality complaints and devastating structural problems

Rot issues related to foam tend to show up around eight years after the initial application, according to Jim Bradley, founder of the building science consultancy Authenticated Building Performance Diagnostics in Cambridge

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