Construction
Roof Snow Load Capacity
Is the snow on your roof a problem? Estimate weight vs typical capacity. If you're seeing sagging, water spots, or cracks — shovel now.
Warning signs to shovel NOW
- Sagging or wavy roofline (look from outside)
- Doors or windows suddenly sticking (frame deflection)
- Cracks in interior drywall, especially near walls meeting ceiling
- Creaking, popping, or groaning sounds from above
- Water stains appearing on ceilings
If you see any of these, get out of the house and call a professional roofer or your insurance company.
FAQ
When to shovel? +
When snow load hits 50% of roof capacity, start watching. At 75%, shovel from the ground with a roof rake. At 100%, do NOT walk on the roof — call professionals.
Wet vs dry snow weight? +
10" of dry powder ≈ 1" of water = 5 psf. 10" of wet snow ≈ 4" of water = 20 psf. Same depth, wildly different weight. After thawing-and-refreezing, snow can hit 25 psf.
Old farmhouse? +
Pre-1950 framed roofs with 2×6 rafters at 24" spacing rate ~15-20 psf. Many have failed under heavy snow events. Get a structural inspection if you live somewhere snowy.