Does Foam Insulation Belong in Green Buildings? 13 Reasons It Probably Doesn't
Lloyd Alter/CC BY 2.0
One of the most controversial subjects in green building these days is the use of plastic foam insulation. At Green Building Advisor, Allison Bailes III distills the issue:
Many think it solves all problems, no matter how poorly it's installed. Some think it's helping to warm the planet and compromise the health of people and pets. In the middle are those who work with it regularly and see both the warts and the beauty of the product.
Indeed there are beautiful things about the product; it has a high R-value per inch and installed properly, seals really well. When people are not calling me an idiot for asking Is Sprayed Polyurethane Insulation Safe? or writing Polystyrene Insulation Doesn't Belong in Green Building, they note "How do you think the product performs so well? Air seal, highest R-value available and sticks to everything - in a product that is chemically inert and DOES NOT off gas once it has cured."
Really? Architect Ken Levenson doesn't think so. He has come up with 13 ways that foam has failed:
- Dangerous toxic ingredients
- Irredeemable global warming potential
- Unacceptably high fire hazard
- Hypersensitive on-site manufacturing
- Intolerant of adverse job site conditions
- Unhealthy off-gassing
- Counterproductive vapor retarder/barrier
- Terribly hygrophobic
- Weak and unpredictable air control
- Inflexible and prone to cracking
- Excessive shrinkage
- Difficult to identify and repair air leaks
- Degrading thermal insulation values
Ken Levenson is an architect with a passive house under his belt, who now sells insulating products at High Performance Building Supply, so some might say that he has a vested interest. He certainly knows how to get our attention, in Why Foam Fails. Reason #1: Dangerous Toxic Ingredients
The chemical companies selling polyurethane foam as green and sustainable, demonstrate chutzpah second only to that of the tobacco and coal industries. Admittedly, if you believe in “clean coal”, foam might be what you’re looking for. But if you didn’t believe the tobacco scientists and executives that cigarettes weren’t addictive, and you think the proposition of clean coal is a sick joke – then maybe it is time to take a closer look at foam.
Like cigarettes, foam fails at the most basic level of sustainability: its ingredients. And as with coal, the effect of its processing and use is significant and detrimental to our environmental well being.
Levenson goes through the ingredients used to produce foam, blowing agents, and the pretty much ineffective flame retardants. It is a fascinating and scary read.
Readers will no doubt point out that most of these chemicals are used in the factory and affect the manufacturers and installers but generally not the public. Others might point out that we really do have better living through chemistry, that all these plastics are critical if we are going to reduce our energy consumption.
It's complicated, but it is an important discussion. I look forward to the remaining twelve chapters.
UPDATE: Interesting discussion on this very article at Green Building Advisor.