Snow accumulation adds weight at about 5 lbs/cubic foot (wet snow). This guide covers calculating snow load, identifying roof stress signs, safe snow removal, and building code requirements.
Calculating Roof Snow Load
Measure snow depth at multiple points on your roof. Multiply depth (in feet) by snow density: light fluffy snow (~2.5 lbs/cu ft), packed snow (~5 lbs/cu ft), wet heavy snow (~8 lbs/cu ft), ice (~15 lbs/cu ft). Compare to your roof design load (check building plans or local code—typically 30–40 lbs/sq ft for residential). Signs of overload include visible roof sag, cracking sounds, doors that stick, and interior wall cracks.
Safe Snow Removal Methods
Use a roof rake with a long extension handle to pull snow off from the ground. Work parallel to the roof deck to avoid damaging shingles. Remove snow starting from the eaves and working upward. Never create uneven snow loads—remove in strips. Do not attempt to chip ice. If snow is too deep or roof too high, hire a professional snow removal service. Never stand on a snow-covered roof.
When to Call a Pro
Frequently Asked Questions
Most roofs are designed for 20–30 lbs per square foot (live load). Wet snow weighs about 5 lbs/cu ft. At 4 feet of wet snow, you are near 20 lbs/sq ft. Ice and compacted snow weigh more.
Visible roof sag, cracking or popping sounds, doors and windows that stick or bind, interior wall cracks, and water stains from roof deflection.
Related Guides
Stay Informed
Get the latest home safety guides and updates delivered to your inbox.