Can Snow Collapse a Roof in the Treasure Valley?
Yes, snow can collapse a roof in the Treasure Valley, but it is rare on a sound, pitched home. Most valley floor houses are built to carry far more snow than a normal Boise winter delivers. The collapses that do happen hit flat commercial roofs, carports, patio covers, and older homes with rotted framing, almost always after wet snow followed by rain. Dodd Roofing and Exteriors inspects roofs across Boise, Meridian, Nampa, Caldwell, Eagle, and Star every fall, and the homes that concern us are the ones already sagging before the first storm.
What happened to Treasure Valley roofs in January 2017?
January 2017 is the winter local homeowners still talk about. Boise picked up more snow in a few weeks than it usually sees all season, then rain fell on top and the pack froze solid. Ada and Canyon counties both declared emergencies, and dozens of roof collapses were reported across the valley. Nearly all were flat or low slope roofs on commercial buildings, carports, covered patios, and agricultural buildings. Pitched shingle roofs on framed houses came through almost entirely intact, although many grew ice dams and leaked. The danger is not snow depth on a normal house. It is water soaked snow on a roof that cannot shed it.
How much does snow weigh on a roof?
Depth is a poor guide. A foot of fresh, dry powder weighs roughly 5 pounds per square foot. Packed, wet snow can weigh three to four times that, and one inch of solid ice weighs about as much as a foot of powder. A rain soaked snowpack is the heaviest load a roof will ever carry, which is why the 2017 collapses came after the rain. A 2,000 square foot roof under a foot of wet snow can be holding 15 to 20 tons.
How much snow is a Treasure Valley roof designed to hold?
Idaho roofs are engineered to the ground snow load in the local building code. On the valley floor in Boise, Meridian, Nampa, and Caldwell that load is modest compared with mountain towns, and it steps up for foothills addresses in Eagle and north Boise. A code built pitched roof in good condition carries a normal winter with a wide margin. That margin shrinks when framing has rotted from an old leak, when two layers of shingles add dead weight, when a patio cover went up without a permit, or when wind drifts snow against a taller wall. If your roof already dips between the rafters, read our guide on what causes a sagging roofline before winter.
Should you remove snow from your roof?
For most pitched homes, no. Snow on a sound roof is safe, and people are hurt on ladders every winter trying to clear it. The warning signs of an overloaded roof are a ridge that visibly sags, new drywall cracks at ceiling corners, interior doors that suddenly stick, and creaking or popping from the attic. If you see those during a storm, get people out from under that area and call for help. Otherwise, use a roof rake from the ground to pull snow off the lower few feet above the eaves, which is also where ice dams build. Never chip at ice or climb onto a snow covered roof. Flat commercial roofs, carports, and patio covers are the exception and need clearing once the pack nears a foot of wet snow. Our post on whether ice dams happen in the Treasure Valley explains the attic fixes that keep meltwater moving off the roof.
Does homeowners insurance cover a roof collapse from snow?
Most standard Idaho homeowners policies list collapse from the weight of ice, snow, or sleet as a covered peril, along with the interior damage that follows. They do not cover gradual sagging, rot, or a roof that failed because it was already worn out, and detached carports often carry lower limits. Photograph any damage and notify your carrier promptly. Our guide on whether insurance covers roof leaks in Idaho covers the documentation carriers expect.
What should you fix before the first snow?
Fall is the window, since sealants and shingle repairs cure best while afternoons stay above 50 degrees. Book a free inspection and have sagging framing, soft decking, or open flashing repaired now through our roof repair service. Confirm attic insulation is level and soffit vents are open, and clear the gutters so meltwater has somewhere to go. If the roof is at the end of its life, replacing it before winter beats patching it in January, and financing is available. More seasonal guides are in our homeowner guide library. Dodd Roofing and Exteriors serves Boise, Meridian, Nampa, Caldwell, Eagle, Star, Kuna, and Middleton. Call (208) 295-9421 to schedule a free inspection before the snow flies.
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