Last winter, many of us got an unwelcome introduction to the havoc ice dams can wreak. Even if you were able to avoid them, there are preventative measures you can take to prepare for Winter 2015. Damage from ice dams can be extensive and the repairs disruptive.
We’ve outlined some prevention tips relating to:
- Ventilation and insulation of your attic.
- Ice and snow shield installation.
- What questions to ask a contractor when installing a new roof.
- What steps to take once it starts snowing.
But first, what is an ice dam?
A line of ice that forms along the roof edge, an ice dam prevents melting snow from draining off the roof. As your attic warms up from the heat in your house the snow on your roof melts. If the temperature outside is warm enough, this water will harmlessly run down to your gutters (this is a good reminder to always make sure your gutters are clear). But when the temperature stays below freezing, this water backs up behind the ice dam and can seep under shingles and into your house.
What causes it?
Three factors create the “perfect storm” for ice dams:
- Heavy, consistent snowfall and below-freezing temperatures
- Inadequate ventilation and insulation
- Poorly installed roofing materials
The first you can’t control. But the last two you can, and should consider addressing before the flakes fly.
Prevention now — ventilation and insulation
To properly ventilate the attic and roof to permit warm air to escape, consider installing any one, or an appropriate combination, of the following:
- A ridge vent
- Soffit vents (or make sure the ones you have are not blocked)
- Roof vents or channels in the attic, from eaves to ridge
Proper insulation prevents heat loss into the attic that causes snow to melt. Consider:
- Insulating your attic floor and the underside of your roof, making sure not to cover soffit vents.
- Eliminating warm air leaking into your attic from around light fixtures, stair trap doors, pipe openings, and anything that cuts through the attic floor.
Prevention now – roofing / ice and water shield
When you are having a new roof installed consider having your roofer install an ice and water shield at least six feet up from the roof edge and two to three feet up the side walls of dormers. Work with your roofer to choose a good-quality material, one that’s substantial in thickness and self-seals around the roofing nails.
Confirm with your contractor that the shield will be installed over the fascia board and into your gutters, with the roof’s drip edge installed on top of the shield. This helps prevent water from finding a path behind your gutters and into your walls. Now is also a good time to have old flashing around any dormers or roof valleys replaced because older flashing becomes brittle and can let water enter.
But before you start any work, it’s important to use a qualified, licensed, professional contractor. There are several questions you should ask to help you choose the right roofer for you.
Once the snow starts – the roof rake
All property owners still need to keep on top of the snow when it starts to fall. A roof rake is an essential tool in this battle. Once you have one to two feet of snow on your roof, rake it off as high as you can safely reach and watch out for any wires. If you need to have your roof professionally cleared, make sure to use a qualified roofer as they understand the right way to clear your roof, mitigating any damage and subsequent repairs or leaks.
We hope these tips help you prepare as we head into winter.