Snow Load Calculator

About Snow Loads

Snow load is the downward force on a building's roof caused by accumulated snow. The weight varies dramatically based on snow type: fresh powder weighs about 5 lb/ft3, while wet packed snow can reach 40 lb/ft3 or more. Most residential roofs are designed to handle 20-40 PSF, but this varies by building code and location. Key danger signs include doors that stick, visible roof sagging, or cracking sounds. When in doubt, hire a professional to assess and safely remove excess snow. Never walk on a roof under heavy snow load.