- Ice dams are caused by too little attic ventilation. Untrue. Ice dams are almost always caused by air leakage. Warm, moist air leaks into the attic from living space, causing the temperature of the attic to rise, melting the snow on the roof which turns into water and runs down the roof until it reaches the cold eaves, where it freezes again.
Complicated roof structures are more susceptible to ice dams and harder to cure.
- Replacing the windows is the first upgrade I should do. Rarely true. Cost-benefit analysis of window replacement usually puts this upgrade toward the bottom of the list, whereas less expensive things like air tightness improvements and basement insulation are much more cost effective (often 10 times as beneficial).
- I need to get my ducts cleaned regularly to improve the air flow. Untrue, unless they have been blocked by construction projects or naughty children. Three separate research projects have shown no significantly discernible difference in the amount of house dust or duct airflow after duct cleaning. CMHC has a free publication on this and many other subjects.
- Fiberglass batts are the best insulation on the market. My experience shows this to be utterly false. Insulating claims for this product are contingent on its position within a properly constructed building assembly. Real world conditions rarely meet these requirements. Its domination of the marketplace, in my opinion, does not reflect the efficacy of the product. This product is also ruined by water, unlike some other insulations.
- Making my house airtight won't allow it to breathe, which is unhealthy for it and me. This is true to an extent, but that is why ventilation is part of any efficient house. There is no such thing as a house that is too air tight, just one with inadequate ventilation. I can help you solve this problem.