To the Editor,
I am writing to expand on some of the information in the article "Insulation Materials," which appeared in the November Reporter. I believe that the following will be of value to the inspector in the field.
First: From 1920 until 1990 (when it closed), most of the world's supply of vermiculite came from a mine in Libby, Montana. This vermiculite, as noted in the article, is occasionally used for attic insulation. It has been found to contain a type of asbestos. If the insulation is not disturbed, there is very little exposure or danger. If it is disturbed, however, asbestos fibers can be released into the air and pose a health risk. Vermiculite was also used, on the floor, in older gas fireplaces, and could also pose a health risk. I believe clients should always be advised of these facts.
Second: In regard to shredded cellulose insulation, manufacturing of this material was once a "cottage industry" and the insulation could be made from old newspapers, in someone's garage.
While the modern, commercially manufactured insulation is treated with a fire retardant, the original material was not. When inspecting an attic with this type of insulation, we always test a sample for combustibility. In one case, the insulation burned and had to be removed and replaced. What's more, I recommend clients should always be advised that only a single sample was tested.
Third: Urea Formaldehyde Foam Insulation was once declared a carcinogen due to outgassing of improperly mixed or applied material. However, this declaration was withdrawn after a prolonged period and the formaldehyde, which is found in many common materials, is now considered an allergen rather than a carcinogen. While the experts no longer consider UFFI a health hazard, this insulation may still pose a structural problem. Due to shrinkage of the insulation and lack of a vapor barrier, moister permeating through the walls can condense against the cold exterior sheathing. This condensed moisture (water) will saturate the open cell foam, which acts like a large sponge. This can result in concealed rot and mold problems within the walls. I personally witnessed the demolition of an older home that had been insulated with this material and noted extensive rot in the walls. It's my opinion clients should be made aware of the potential problems when this type of insulation is observed.
Victor J. Faggella
Victor J. Faggella is the president of Centurion Home Inspections, Inc. The ASHI Certified Inspector (#478) serves on ASHI's Technical Review Committee. He has been a professional home inspector since 1970, and has personally inspected or supervised the inspection of more than 11,000 homes.