Ice dams form when warm attic air melts snow on the upper roof and the meltwater refreezes at the colder eaves. The ridge of ice traps more water behind it, which backs up under the shingles and into soffits, walls and ceilings. Chipping at it with a hammer damages the roof. Hammerline Roofing helps homeowners remove ice dams safely and, more importantly, stop them from coming back.

How we prevent and treat ice dams

Eave protection membrane — self-adhering ice and water membrane at the eaves and valleys so backed-up water can't get through to the deck.
Ventilation and insulation — improving soffit intake and exhaust and finding warm-air leaks into the attic (see roof ventilation).
Heat cable — roof and eavestrough heat cables for problem areas that can't be fixed any other way, installed on a dedicated circuit by a licensed electrician where required.
Steam removal — low-pressure steam cuts channels through ice without damaging shingles the way picks and hammers do.
Eavestrough fixes — re-hanging troughs pulled down by ice and adding downspouts where water freezes (see eavestroughs).

The order we work in

Stop the leak. If water is coming in, we open channels in the ice to let it drain.
Find the heat source. We look for missing insulation, open attic hatches, bathroom fans and blocked soffits.
Fix the roof edge. At the next reroof, or sooner if needed, we install eave protection to the depth your roof needs.
Add cable only if needed. Heat cable is a last resort, not a first step.

Ice dam leaks often damage the deck and fascia, so check roof repair once the snow is gone.

Good to know

A few simple habits help between visits. Keep eavestroughs and downspouts clear before winter so meltwater has somewhere to go. Use a roof rake from the ground to pull snow off the lower few feet of the roof after heavy snowfalls, without climbing a ladder. Make sure the attic hatch is weatherstripped and insulated, and that bathroom fans vent outdoors. If ice dams keep returning in the same spot, that location is telling you where heat is escaping.

What affects the cost of ice dam prevention

Ice dam costs fall into two parts: dealing with the ice and preventing it. Steam removal is priced by time and is affected by roof height, access and how much ice has built up. Prevention depends on the cause: improving soffit intake or attic air sealing is often modest, while installing eave protection usually happens during a reroof. Heat cable costs depend on the length of roof edge and eavestrough covered, and may need a dedicated electrical circuit installed by a licensed electrician.