Spray Foam and Your House

As the season approaches where many energy or weatherization companies want to reduce your homes energy consumption there are several issues you should consider before you spray foam your house.

Even though many spray foam companies tell you there are NO issues with off gassing of their products after application this may not always be true.

Before you spray foam the basement or crawlspace in your home make sure that you do not have any moisture issues.  If you do not eliminate the moisture and you spray foam, your house becomes a big straw that draws the moisture up into your home.  I have opened up cavities in basements that have been spray foamed and the sils have completely rotted out.  Prior to having your home sealed with a product that is easy to install and VERY difficult to remove have a independant consultant evaluate your home to determine if spray foam would be applicable.  Not every home is a “fit” for spray foam.

A group of professionals from EPA, OSHA, NIOSH, CPSC (Consumer Product Safety Commission) formed a SPFI (spray foam insulation) workgroup to address exposure concerns they have around the use of SPFI in homes. The group is particularly concerned because of the dramatic increase in the use of this class of material and the lack of communication of risks to workers and the general public who may use DIY products. There is still a great deal that isn’t known about these products, but plenty that is known. There are also apparently many misleading marketing claims about the lack of toxicity and safety of using them.

SPFI is a 2-part product, one of which contains a diisocyanate. This compound is known to be the leading cause of occupational asthma. There have been deaths attributed to diisocyanate exposures. It is also a sensitizer, meaning exposure to it can make you hypersensitive to it. This is very problematic because polyurethanes are everywhere, once you are sensitized, you could get triggered by a something as common as a floor coating.

NIOSH did an investigation September 2009 at 4 different worksites using SPFI. They found many of the same concerns that lead them to issuing an alert in 2006 for the industry that makes truck bed liners using a product with diisocyanate.

Recommended practices for workers applying SPFI:
• Cover all skin with disposable suit and gloves
• Wear full face respirator with supplied air
• Isolate work areas from other occupied areas
• Exhaust air to outdoors with an appropriate filter
• HVAC system should be shut down before using SPFI

Helpers also need to wear full skin protection and full face respirator. Skin contact can cause sensitization.

NIOSH saw a high percentage of workers not wearing respirators during their field studies. There is particular concern that many workers are not well educated, fairly transient and not well trained.

Cure time for SPFI varies between 1 hour and 1 week, depending on formulation of SPFI, the ambient temperature, humidity and other factors. Off-gassing during this time could be harmful to residents, especially children.

EPA is launching a diisocyanate website with information that they have. They are very clear that they don’t know everything there is to know about this product. They feel they know enough to say that workers should be better protected than they are now. They are doing research on cure times and concentrations of toxic monomers that are released during curing.

OSHA will do free consultation for small and medium businesses. OSHA is hiring more people to do enforcement around this issue due to increase use of SPFI from stimulus funding. There was some discussion about no worker protection guidelines connected to weatherization work resulting from stimulus money.

It’s really easy to get people upset about possible health hazards in their homes, especially if we glibly reassure them there are no risks to certain products whether we know that to be true or not. In building, as in any other endeavor, it’s easy to convince ourselves something is true if we really want it to be true. I don’t know how safe spray foams are. I do know they’re used a lot, and I also know that the quality and safety control within the industry is (at least in my market area) VERY uneven. I also know that there’s rampant confusion regarding what building codes really require for thermal and ignition protection; that what sales reps say often contradicts what their own literature says with regard to ASTM testing among other things; and that, of all the newly prevalent products we use to make homes perform better, spray foams worry me the most in terms of potential liabilities.

As a indoor environmental consultant, in terms of specific products, we no longer recommend SPF it to our clients as there are many other products that can be utilized and reduce your energy consumption.

To sum up the partial list of negatives:

It’s so toxic to install that humans need full skin isolation and protection from the chemical components. Over exposure to isocyanurates can lead to devastating chemical sensitivities, including permanent respiratory damage (Direct from Bayer, a major manufacturer: http://www.greenbuildercollege.com/studyguides/BaySystemsSprayInsulation…).

During installation, if the chemicals are not mixed correctly or at the proper temperature you can get incomplete curing of the two chemical components, either of which is toxic on its own. This is a very rare situation, thankfully, but this rare risk is still one I wouldn’t ever recommend one of our clients take with their house.

And, once applied (correctly or incorrectly) a house is bound up and glued together in a manner that is impossible to reverse, limiting the ease of future renovations drastically, even simple actions like adding wiring or fixing plumbing issues.

It does nothing for thermal bridging at typical supplied depths, wood framed buildings still end up with an ~R-6 insulation gap every 16″ at each wood stud.

And worst of all, it’s extremely expensive, far worse than other comparable insulation materials…

But, none of these specific technical issues gets at your main point, which is consumer confusion, because every point I have listed will be eagerly refuted by the closed cell spray foam industry, which has more lobbying money available than I have time to type.

And this is where we need to get to work changing these larger systems. It’s why I think we can’t shy away from pushing for policy changes, more than trying for individual behavioral change.

There are viable substitutes for all these blowing agents available, this is a US regulatory problem at heart.

Here is a news story out of Florida on families dealing with spray foam in their homes…


If you have to have spray foam use a company that’s been around for a few years and won’t be hard to find if you have issues.  Have a evaluation of your home done by a qualified third party building inspector, not affiliated with the spray foam company, prior to any energy efficiency measures to ensure your home is the right fit for spray foam.   The cost of the inspection will be significantly lower than having to deal with removing the spray foam from your sick home.

TP Environmental Consulting is a Third Party Building Inspection certified by the State of Maine Code Enforcement.