If you own an older home, odds are you’ve had some issues with ice damning around the eaves of your house’s roof. Maybe it only happened once, a small brown spot on your ceiling just inside the wall line, or maybe it happens every time there is more than a couple inches of snow on your roof. Either way, ice dams are no fun, causing ugly damage to your homes interior and, if not addressed, can cause mold, wrecked insulation and serious structural rot.
So what’s the deal? Why do ice dams form and HOW do you fix them? Well, let’s star with the “why”. There are a couple possible culprits to blame for ice dams. Sometimes it’s only one of these, sometimes it’s all of them working together like a little home destroying, pain-in-the-behind team.
The first thing we look at is attic insulation. If your attic insulation is thin, or otherwise inadequate, it allows tons of your (expensive!) warm house air to circulate into the attic. This is bad. For a number of obvious reasons, but also because it almost certainly guarantees that you are going to be cooking up some very big ice dams.
The second thing we look at when we have an ice dam problem to address, is your attic ventilation. Attic ventilation is a critical component of your homes weatherization system, ensuring that your attic air is the appropriate temperature for the conditions. There are a number of styles of attic ventilation, but to work, they need to be properly balanced between your outflow and intake areas. We use the GAF Ventilation Calculator to helps us determine the correct amount of intake and outflow components. Without good ventilation, warm, moist air from the house stays trapped in your attic, melting snow from underneath only to re-freeze and form that nasty ice dam when it reaches your eave. (The moisture in the air, if not properly exhausted) can also condense and freeze on the underside of your roof, only to melt off when the outside temperature is above freezing, leading to a roof “leak” on a perfectly sunny day, with no snow on the roof)
Ok. HOW DO I MAKE IT STOP?!? That’s a good question and we are glad you asked. First–insulation. This is one area where more is almost always better (unless you put in so much that it blocks your intake vents, then….it’s just too much) for helping with your homes heat bills and heading off ice dam formation. Second – ventilation. You don’t need to replace your roof to address ventilation issues, though that’s a perfect time to do so. Almost all of our ventilation products can be added as necessary to almost any existing roof. Also, the great thing is, we can do it at any time of year. You don’t need to put up with the annoyance and damage that ice dams cause for months and months.
One last thing – ice and water shield underlayment is a great component as a last line of defense against ice dam damage and we highly recommend it for any new roof installation. It’s rubberized and adhesive backed to seal up around any penetrations and KEEP THAT WATER OUT!