Got Icicles? Moisture-Proofing Your Attic


Pretty, fun to photograph, not good for the home. You have a problem if you see this.

With the long cold winter we’ve had, we’ve seen a lot of moisture build-up in attics. Sometimes it’s so bad, it leaks as if it’s raining in the home. When leaking starts, people are almost always tempted to call the roofer. But 9 out of 10 times, moisture problems such as ice dams are actually caused by lack of insulation/air-sealing or venting problems.

If air inside your home’s living area escapes into your attic because of air gaps in the house or lack of insulation, there’s a problem. For one, you’re heating the outside. That’s not green, and who can afford to waste energy these days? The problem worsens if your venting system can’t keep up, because the warm, moist air will condensate on the first cold surface it finds—normally the bottom of the roof deck. Over long and cold winters like the one we’ve been having, all that moisture and condensation will keep freezing and building up in the attic. When it melts, it will drip all over - if into the house, at least you’ll be alerted to the problem.

Ice Dam Diagram

Now that we have you a little scared, think back to January. We had heavy snow falls, and it was blistery cold for weeks. If you had large icicles—longer than 12"—or if you had a large build-up of ice on your roof, you need to crawl in the attic and inspect. You’ll want to make sure you have at least 20" of insulation in the attic and that all penetrations from the ceiling to the attic are sealed. You’ll want to see the walls and tops of the walls insulated but with air chutes letting in air every 2 feet. If you shut off your flashlight, you should be able to see light coming in along the roof edge. You’ll also want to make sure air can escape through a ridge vent or roof vents but never both. If your home doesn’t meet all these criteria, you may have lost energy and built up excess moisture in your attic, which over time will create mold and rot out your attic and roof.

Not up for inspecting things on your own? You’re in luck! Frey will come out and do an inspection for free. Give us a call to set up a time. We’ll help you prioritize what it takes to stop wasting energy and, more important, protect one of your biggest investments—your home.