Seattle Home Inspector's Blog

     Recent Horror Movies that you may have seen include: 

“Night of the Living Lead,”

“The Shining Vermiculite,”

“King Mold,”

“Mold of Frankenstein,”

“Alien Asbestos,”

“The Lead Thing,”

“Asbestos Stories,”

and “Dr. Lead & Mr. Mold.”

     These movies are currently so popular, and watched so frequently, that most movie goers have long forgotten the old classic, “The Shrinking Formaldehyde.”

     Urea-Formaldehyde foam insulation was very popular in the 70’s and was pumped into the walls of hundreds of thousands of homes around the country.  By 1982 it was banned in the US (even though eventually the ban was lifted because of lack of evidence).  It its hay day, “The Shrinking Formaldehyde” received considerable attention and was reviewed extensively in the press----rivaling the great movies of our day. 

      The problem with the stuff was that it out-gassed Formaldehyde after installation and supposedly made people sick-----it is after all, an embalming fluid.  Current science shows that many of the “studies” that the press latched onto, when reviewing “The Shrinking Formaldehyde,” failed to meet minimal scientific criteria for evidence of it’s causing health problems. One of the key elements of a good Horror Movie is that fear must be instilled and maintained in a heightened way.  Because the actual movie could not sustain this fear on its own, the movie has fallen into the Horror Movie dust-bin----nearly forgotten.

     Some of the current Horror Movies will also be relegated to the dust bin in time.

     Urea-Formaldehyde insulation had a second property that ultimately ended up making it “functionally” a poor choice of insulation.  The general principle was to inject two chemicals into the wall cavity which combined to create a foaming mass that expanded to fill every little nook and cranny----it did that VERY well.  The problem is that it rapidly began to shrink after installation leaving the mass pretty much floating in the center of the space----allowing for air to move around in the cavity through convection.  It is the stopping of convective loops that defines how good a job an insulating material is doing.

     As a Seattle Home Inspector I still come across homes insulated with Urea-Formaldehyde.  Today’s concerns with the insulation is more about informing the buyer as to what the material is, its history, and what the buyer can do about it----including nothing. 

     While it is likely going to mean the house is not as well insulated as it could be compared to cellulose fiber for example, the house will still be considerably better insulated than if there was nothing in the wall at all, as it still represents “some” restriction of air movement.  The health hazards related to the formaldehyde out-gassing are non-existent after the number of years that have passed since the last of it was installed.  Most out-gassing was complete after a few days of installation.

     The picture below shows a couple of things.  It shows how well the Urea-formaldehyde was able to fill even this abandoned electrical panel box on the exterior of the home----getting into the box through the holes that used to be for the wires.  But, also notice, the distinct marks where the foam has shrunk away from the edges of the box leaving us with a “classic” example of how the material has shrunk. 

     Can you see the line made by the edge of the box all the way around the edge of the foam block? 

     All the little dents are where people----including me-----could not resist touching it-----proof that this horror movie has been justifiably relegated to the horror movie dust bin.

Charles Buell, Seattle Home Inspector