Most 'Experts' Got It Wrong: Ice Dam Roof Damage is Not an Insulation Problem

Despite good intentions, most media coverage on ice dams is misguided, and can actually make problems worse

MARCH 11 2014 – CHICAGO – This winter has been a record-breaker, but few homeowners know what they can do about it. Roof snowmelt re-freezing at the eaves (called ‘ice dams’) is a problem for many homes. It causes structural damage to roofs and walls every winter. And with more snow on the way, the immediate question is, what can a homeowner do about it?

Misguided sources, including home improvement shows and news networks, say that ice dams are made when hot air escapes from the home into the attic because of missing insulation, and artificially warms the roof. This is only half right– since warm air rises, it does indeed push up through the ceiling, into the attic or roof cavity, but insulation cannot, and does not, fix air leakage. The only thing that can fix air leakage is airtight materials, which insulation is not.

Consider your furnace filter, for example: air goes right through it, and filters out particles that could damage the furnace or air conditioner… AND it’s made from fiberglass, just like insulation. So really, the air that pushes out of your home into your attic will be the cleanest air in the whole house, if you have a well-insulated attic. But the big problem remains; warm air will still leak out.

Solving ice dams once and for all with Air Sealing is the only solution. Luckily this is very affordable, needs no maintenance or replacement, and doesn’t consume energy (unlike the ridiculous heat wires you can string along your eaves as a band-aid). Never install more attic ventilation before the attic floor is air sealed- this just accelerates the leakage of air from the house to outdoors. And never add more insulation before air sealing- this only makes the attic colder, so the warm air leaking into it condenses everywhere, which can lead to mold. Hire a Home Performance Contractor for air sealing, not just any contractor. Home Performance Contractors test before and after their work with a blower door, to prove you got what you paid for, and to prove that the problem is actually solved. The best part of Home Performance is that proof is possible.

Smart homeowners are opting for a comprehensive home analysis with performance testing, before investing in improving any part of their home. This ensures that home improvements are prioritized, cost effective, and that each improvement makes the home more comfortable, durable, healthy, and energy efficient. It also ensures that you never flush money down the drain guessing at fixes. See the Home Diagnosis Guide to Finding Home Performance Pros to locate help in your area.