Insulation Myths

Green Renovations – Insulation myths

Steve Maxwell writes a column for the Toronto Star as well as being the editor of Canadian Home Workshop magazine. A recent article of his, laid out the true story of fiberglass insulation ratings, vs. actual tests. What Dr. Tony Scott at Brock University found was that closed cell foam insulation rated R-17 delivered R-17 while an R-19 building only delivered R-4 due to air movement within the hollow wall / fiberglass during very cold weather. The closed cell foam was an air barrier and superior insulator. Cool! Well not so cool in -25 weather. Something to think about.

Challenge – what to insulate with on an old brick house – drill holes and blow in insulation or add rigid foam to walls. If the wall cavities are smooth (old brick likely have lots of mortar pushed out in air space) then blown insulation will provide some insulating value although there will be pockets. Moisture migration may also be a factor. Better solution is cover with 2” of rigid foam on the outside if the walls are to be resided or inside if the interior walls are to be replaced. This comes from another article of Steve’s. Check out Steve’s information at www.stevemaxwell.ca