Messages and Online Forum Q&A

Re: Off-Gasing of Foam Insulation

From: info@builderswebsource.com
Category: HVAC
Remote Name: 63.198.181.43
Date: 05 Mar 2001
Time: 10:11 PM

Comments

Comfort Foam is a sprayed-in-place polyurethane insulating foam. Additional information on this product is available on their website at:

http://www.comfortfoam.com/

According to their FAQ, the following excerpt is Comfort Foam's position on polyurethane outgassing and is shown here for your convenience:

"Once the foam has cured, usually within twelve hours, the foam becomes an inert plastic mass and only minute amounts of the blowing agent outgassing occurs over time. I say minute because we know that some of the blowing agent in the foam is not present after time. Some of the blowing agent is absorbed into the cell structure of the foam and some of it is released. To say how much and to what impact this loss of blowing agent is hard to quantify.

Infra red spectrometer measurements and computer modeling of blowing agent retention in foam have shown the half-life of the blowing agent in the cell structure to be around 350 years. These observations were made after testing "core" foam, that is to say foam without the less permeable "skin" commonly found on field-applied foams. And, of course, the foam was not tested with any drywall covering as well. Only under laboratory conditions can this be tested and if you cannot measure it, how can it have impact when the blowing agent itself is not a recognized health risk?

In the application process, when the two chemicals are atomized and mixed to make foam then sprayed onto the substrates are the exposure to the isocyanurate chemicals the greatest. Our Qualified Contractors are all encouraged to use fresh air equipment and the helper and any observers are encouraged to wear 3M type particulate masks when in an enclosed area like a room in a building. Two inches of our product has a perm of less than one. That is a good thing. Two inches of COMFORT FOAM will do the most effective job of stopping air infiltration, exfiltration, convection and in your environment, solar driven moisture into the stud cavity. Two more inches and you would have an R-28 wall with superior durability that will exceed code minimums for most residential applications in sidewalls for the foreseeable future. The most cost effective (not necessarily the most energy efficient or best wall system) is an inch of foam in combination with a conventional insulation system like fiberglass, mineral wool or dry blown cellulose."

A good article discussing various health effects of insulation is available at the Healthy House Institute website at:

http://www.hhinst.com/ArtInsulation.html

Some additional points to consider are:

1) If the foam is being applied to the exterior of the structure, then problems with outgassing would likely be minimal with respect to the home's interior;

2) If the foam is being applied between the stud cavities, then outgassing is a potential issue, which in our opinion is not sufficiently addressed in the foregoing recitation.

3) Finally, while it's important to build a weather-tight home, indoor air pollution from a variety of sources has become an increasing problem. Older homes could "breathe" better with their cracks and insufficient insulation. Newer super insulated homes can actually worsen indoor air quality. As a result, the HVAC system must account for fresh filtered air intake in combination with an air-to-air heat exchanger to conserve energy.

Builders Websource

Article Tools

Builders Websource® is a corporate member of ASTM International—a non-profit engineering body dedicated in part to the standardization of building materials specifications, products, systems, and test methods for improved health, safety, and reliability of residential and commercial structures.

Copyright © 1999 - 2018 Builders Websource®, a BUILDERA™ company. All rights reserved.