If You Don't Have Ice, It Doesn't Mean You Have Good Insulation
December 17, 2015
Many homes in Canada suffer from "ice dams" during snowy, icy winters. And not all contractors understand "ice dams" well enough to explain to the homeowner. The basics are the important part. Heat escapes from inside the home, warms parts of the roof, and the snow melts in those warm parts. At this point its water that trickles down the various parts of the roof, and when it hits cold parts, it freezes. The freezing ice accumulates and eventually forms an "ice dam". Ice damming can seriously damage the roof, the shingles, and the interior ceilings of a home. The antidote, of course, is good insulation, and when properly installed, it will effectively stop ice damming and the associated damages. However, the absence of ice damming does not necessarily mean that the roof and attic have good insulation. It only means that the insulation envelope is currently adequate and stable. As such, the potential for ice damming could be looming. The truth is, it's not just about good insulation. It's about a complete "system" that incorporates airtightness, ventilation and good insulation all together. Ice damming or not, the air barrier in a home is what keeps indoor air from escaping, and leaking air is one of the biggest challenges for an insulation contractor. In many cases, energy efficiency in a home is not related to a roofing issue, but rather to an insulation issue, where good insulation could be the remedy. Experienced insulation contractors can quickly isolate and evaluate the extent of air leakage in a roof or attic. And while good insulation may be part of the solution, the essential thing is to seal the space tight. This is most effectively solved with Spray Polyurethane Foam, an application that completely seals roofing vents, HVAC ducts, and even recessed lighting fixtures. Good insulation is still important, but nothing beats sealing up every little hole, crack and crevice. When sealing is complete, a reliable contractor will recommend a good insulation product to suit the requirements of the project. Here, fiberglass batts, fiberglass blown insulation, and Spray Polyurethane Foam (SPF) are all possible options. Today, more and more insulation contractors are suggesting SPF as the better option overall. In fact, for cost effectiveness, some of the best installations combine SPF with one of the fibreless products in a "hybrid" install. Once again, good insulation is only one component of a complete job. Proper ventilation in attics and roof cavities is a must, and any good contractor will insist on it. In particular, preventing ice dams has as much to do with proper ventilation as it does with good insulation. But importantly, even a well-ventilated space will not perform without sealing the space completely. The best outcomes will result when sealing, ventilation and insulation are all working together. As it is, Spray Polyurethane Foam is more than just a good insulation product. A professional installation will ensure the highest possible R-Value; the most effective air barrier/vapor barrier; and an insulation project that is fully code-compliant. The best news for the homeowner: big cost savings on heating bills during the winter, and air conditioning bills in the summer.