Snow load in Monroe County, Michigan: pg = 20 psf
The code ground snow load in Monroe County is 20 psf (0.96 kN/m²) — 79 of 83 counties have a higher value in Michigan. The calculator below is prefilled with that value: choose exposure, thermal condition, risk category and roof slope to get the roof snow load.
| Where | pg (psf) | kN/m² |
|---|---|---|
| Entire county | 20 | 0.96 |
Educational estimate only. Excludes drifts, sliding snow, rain-on-snow surcharge, unbalanced and partial loads, and any local amendments. ASCE 7-22 changed the method (risk-targeted pg, no Is in pf). Design loads must come from the adopted building code and a licensed engineer.
Check the snow load for a real project
Upload the drawings or describe the roof — Planium works out exposure, drifts at parapets and roof steps, and what to confirm with the Monroe County building official.
From ground snow load to roof snow load
ASCE 7 converts the ground snow load into a flat roof snow load with pf = 0.7 · Ce · Ct · Is · pg. With pg = 20 psf, a typical heated, partially exposed home in suburban terrain gets pf = 0.7 × 1.0 × 1.0 × 1.0 × 20 = 14 psf. Roofs sloped below 15° must also be checked against the minimum load of 20 psf. Steep roofs shed snow, so the sloped roof load ps = Cs · pf falls once the slope passes about 30° on a warm roof.
Drifts usually govern the critical members: snow piles up against parapets, at lower roofs next to taller buildings and in valleys, and can reach several times the balanced load locally.