How Much Snow Can My Roof Hold?

The short answer: most modern code-built homes in the US are designed to carry between 20 and 40 pounds per square foot (psf) of roof snow load, depending on location. Whether the snow on your roof right now is within that limit depends on two things: how much it weighs, and what your roof was built to handle.

Find your design snow load

The design snow load is set by your local building code, based on your ground snow load and ASCE 7. Your building permit or structural drawings will state the design value. If you don't have those, our calculator estimates the ASCE 7 code value for your location. A typical single-family house in the Northeast is designed for 30–40 psf; in the Midwest, 20–30 psf; in mild climates, as little as 10–15 psf.

Estimate the snow on your roof now

Measure snow depth on the roof (or on a flat surface nearby as a proxy). Then estimate density: fresh powder is roughly 5 pcf, settled snow is 10–15 pcf, and wet, compacted snow after a warm spell can reach 20–25 pcf. Multiply depth (feet) by density to get the current load in psf.

Warning signs of too much load

Sticking interior doors and windows, sagging ceiling drywall, new cracks at door corners, and audible creaking or popping are all signs the structure is under stress. If you see any of these after a heavy snow, take them seriously and consider snow removal or a professional inspection.

When to remove snow

If your estimated load approaches 75% of the design value, or if you see structural warning signs, start raking. Use a roof rake from the ground; do not climb onto a snow-loaded roof. Focus on getting 2–4 feet of snow off the eave edge; you don't need to clear the whole roof. Clear one section at a time to avoid uneven loading.