The ever-shifting wintry weather is causing a familiar sight in Douglas County: ice dams.
They occur when heat leaks into an attic and melts the underside of snow on the roof.
If weather conditions are right - an abundance of snow combined with big swings in the temperature - ice dams flourish.
Melted snow flows down the roof surface until it reaches a cold spot, like the eaves or soffit. There, it forms a frozen dam while more snowmelt and ice pile up behind it.
In some instances, all that melting and thawing just creates pretty ice formations, but ice buildup can cause big problems by backing up under shingles, damaging them and allowing water to leak to the ceilings and walls below.
If ice dams must be removed, the Minnesota Department of Commerce suggests hiring a professional ice dam removal company that uses steamers. It also recommends some basic measures to prevent future ice dams and avoid costly home repairs.
"Removing ice from roofs with shovels, chippers, axes, chemicals or heat can damage shingles, gutters and other building components, and can be very dangerous," said Commerce Commissioner Mike Rothman in a news release issued Tuesday. "To prevent ice dams in the future, the best course of action is to attack the root cause of ice dams, which is attic air leaks. Sealing those air leaks will prevent ice dams and save on your energy bill."
To avoid these types of problems and eliminate most ice dams, attic air leaks around wires, plumbing vents, light fixtures, and chimneys must be sealed with caulking or expanding spray foam, and attic insulation should be installed to a minimum R-50 as space allows, according to the commerce department.
A first step in solving ice dams and to make your home more energy efficient is to have an advanced energy audit.
The audit will use equipment such as infrared cameras to identify air leaks and will offer action steps to prevent ice dams. Advanced energy audits can be facilitated by your gas or electric utility and members of the Minnesota Building Performance Association (www.mbpa.
Once the problem areas are diagnosed, get bids from several licensed contractors and have the work done.
WHAT NOT TO DO
The wrong "fix" can cause more harm than good. Here's what the commerce department says not to do in addressing ice dams:
Installing heating cables will shorten the life of your roof and cost you money to operate.
Removing ice with shovels, chippers, chemicals, or heat can damage shingles, gutters, and other building components and can be very dangerous.
Adding roof vents, including powered vents, will not eliminate ice dams, and often makes the problem worse.
Inadequate insulation, especially near the eaves, is a contributing cause of ice dams. Adding insulation, especially on the top plate of exterior walls, can reduce heat transfer to the roof deck, but insulation alone is insufficient to stop air leaks or prevent ice dams.