Ice Dams and Heavy Snow on Spokane Roofs: Warning Signs

What is an ice dam, and why does it form on a Spokane roof?

Heat from inside the house warms part of the roof. Snow on that warm area melts, and the water runs down toward the eave. The eave is colder, so the water refreezes there and builds a ridge of ice. The next melt has nowhere to go, backs up behind the ridge and can work its way under the shingles.

Warning signs you can see from the ground

Walk around the house and look up. Do not climb anything for a closer look.

• A ridge or bulge of ice along the eave or in a roof valley
• Thick or repeated icicles
• Ice behind or over the gutter, if you have one
• Bare, melted patches on one part of the roof while the rest is still covered in snow
• Water or ice marks on the soffits or siding

Icicles alone do not prove an ice dam or show how big it is. They are a reason to keep watching.

Warning signs inside the house

Look for stains or damp spots near an exterior wall, moisture in the attic, or a new drip after a freeze and thaw. If water is already coming inside, read what to do if water is already coming inside first. For damage on the roof itself, see our page on roof repair in Spokane.

How much snow is too much for a roof?

There is no safe number of inches. Load depends on how wet the snow is, drifting, roof shape, ice underneath and rain falling on top.

The City of Spokane does publish a design figure: its building code lists a ground snow load of 39 lbs/ft2 and a minimum roof snow load of 30 lbs/ft2. Those are design criteria for new construction. They are not a safe limit for your house, and they cannot be turned into inches of snow.

Signs you should leave the building and get structural help

Treat these as serious: a visibly sagging roof or ceiling, popping, cracking or creaking sounds, doors or windows that suddenly stick, new cracks in walls, or a severe leak. FEMA’s snow load guidance says to leave promptly and contact your local building authority or a qualified design professional. A roofer is not a substitute for a structural engineer here.

What to do and what not to do

• Do not climb onto an icy or snowy roof.
• Do not chip at ice with a hammer, pick or other sharp tool. It damages shingles and can hurt you.
• Do not stand under the eave, where ice can fall.
• A long-handled, non-metallic roof rake can be used from the ground, but only if the footing is safe and you are well clear of power lines. If you are not sure, leave it.

How to prevent ice dams next winter

Prevention means keeping the roof deck evenly cold. University of Minnesota Extension says to start by sealing air leaks from the house into the attic, then look at adding insulation; good attic ventilation also helps. The Insurance Institute for Business & Home Safety recommends the same measures. Much of that is not roofing work; the right contractor may be an insulation or weatherization professional. No fix can promise you will never get an ice dam. For fall preparation, see our Spokane roof winter checklist.

When to call a roofer

Call after an ice or snow event if you see missing or lifted shingles, bent flashing or water stains. A free roof inspection looks at shingles, flashing and seals, vents, gutters and drainage, and decking. We offer roof repair for leaks, shingles, flashing and gutter-related issues.

To get an existing ice dam removed, look for a professional who does ice dam or roof snow removal. If you see structural warning signs, call the building authority or a qualified design professional.

Common questions

How do I tell if I have an ice dam? Look from the ground for ice ridges at the eave, heavy icicles or uneven melting.

Can I remove an ice dam myself? We do not recommend climbing or chipping. Both can injure you or damage the roof.

How much snow can a roof take? It depends on the snow, the roof and the building. Watch for the structural warning signs above.

Does insurance cover ice dam damage? Coverage depends on your policy and your insurer.

Get your roof looked at

Call us on (509) 230-0632 to book a free roof inspection. We serve Spokane, Spokane Valley, Liberty Lake, Airway Heights, Cheney and Deer Park.

Avidus Roofing & Exteriors. Licensed and insured. WA Lic. AVIDURE761B3.