With winter here, ice dams can be a major problem for homeowners. Here are a few things that you can do to prevent them.
What is an Ice Dam?
An ice dam is a continuous piece of ice that forms along the edges of your roof. It doesn’t present a problem while frozen, but when it melts it can seep under the shingles as far as 10 feet to cause damage.
Early signs of damage from an ice dam include rust spots on sheetrock fasteners or soft areas in the sheetrock. You may also see water stains or peeling paint, sure signs of water infiltration. Mold and mildew may also grow in the walls and cost thousands of dollars in damages.
What Causes Ice Dams?
Ice dams build on the roof when snow melts due to a warm attic and then the water refreezes as the water runs towards the cooler, outer edges.
Preventing Ice Dams
Escaped home heat rises into the attic and heats the roof. When the attic temperature of your home is too warm, it causes snow to melt. Consequently, the first line of defense against ice dams is to create a cold attic.
By creating a tight barrier between the heated area of your home and the roof, you reduce the chances of snow melt and ice dams. You’ll also lower your heating bills.
Seal Attic Gaps
Your home probably has many places where heat can escape to the attic. These include an attic access, ducting, pipes, recessed light fixtures and the chimney. Sealing these gaps may involve a bit of a hunting expedition it is well-worth your time. When sealing gaps around hot pipes or a chimney, use fire-resistant materials such as furnace cement caulk.
Ensure combustion appliances operate properly once you seal gaps. You do not want them to spill carbon monoxide into your home.
Sealing gaps does not exclude the need for proper insulation. According to Energystar.gov, insulation below floor joist height means you need to add more. Most attics need an R-value (resistance to heat loss) of at least R-30: between 10 and 14 inches of insulation. Check the recommended R-value for your zone here.
When adding insulation, choose blown cellulose or fiberglass instead of batts. The small particles eliminate gaps around the structural members. Do not block vents or fans if you decide to do the work yourself.
Attic ventilation is extremely important for all homes, but particularly for those prone to ice dams. They draw in cold air and expel warm air to keep the attic cool.
Experts recommend an 8 x 16-in. vent every 300 sq. ft. of attic floor area, or one in every other rafter in the soffit. Either that or use a strip vent along the entire length of the attic. Also install a ridge vent along the peak.
Use caution if you want to do the work yourself. Roof work requires expertise and some roof types are not easily vented. Professionals have the equipment and experience to work at high heights safely, and can recommend solutions if you have an old home without an attic or your home has dormers, angled ceilings, or skylights.
Some homes still have problems with ice dams even when the roof is cold. This can be due to the roof type causing snow to accumulate in roof valleys, areas difficult to keep cold. These secondary measures may prevent this.
Install Adhesive Ice-&-Water Barrier
Install an adhesive ice and water barrier between 3 and 6 ft. from the roof’s edge when it’s time to re-roof. In most areas it is a building code requirement, but check with your roofing contractor.
Use a Snow Rake
When you remove the snow from the roof, it does not have a chance to melt and freeze. Snow rakes come on a telescoping pole with a scraper set at a right angle on the end.
Don’t use a snow rake on a ladder. It’s labor-intensive work you must perform with care to avoid breaking shingles, but it is an effective, inexpensive solution.
Use Heat Cables
When nothing else solves the problem, install heat cables. They’re basically high-resistance wires you mount in a zig-zag pattern on the roof. Ensure they’re plugged into an outdoor ground fault circuit interrupter receptacle.
You’ll also need to run a cable inside a downspout so it does not freeze the water as it travels off the roof.
Remember, ice dams themselves aren’t usually your greatest concern. It’s the water damage they can cause which can be costly and difficult to remedy.
Most homeowners have an HO-3 policy, or special form policy, which covers damage to building components such as drywall, paint, and wallpaper, caused by ice damns. However, remedying or removing ice dams is a homeowner’s maintenance responsibility so you must take measures to prevent them and minimize damage if one starts to cause leaking in your home. If you already have an ice dam on the roof, hire a professional. They’ll steam it off, hopefully before it damages your home and contents.
Don’t ignore ice dams. Discover the causes and correct them. You’ll avoid frustration, water damage, costly repairs, and possibly an insurance claim, higher premiums, and a mark on your home’s CLUE report.