Rock County, MN Roof Snow Load - 28 psf
How much snow is too much for a roof in Rock County, MN?
28 psf: that's what ASCE 7-22 requires a typical heated home's roof in Rock County to carry.
Picture it, not just weigh it: 61.6 in. if it's fresh powder, 22.4 in. once it settles, or a mere 5.6 in. if it's ice. Modern-code homes carry a load like this without issue; an older addition, a carport, or any flat-roofed section is where it is worth checking first.
Rock County in numbers
- Design roof snow load28 psf
- Ground snow load, ASCE 7 map40 psf
- National rank#265 of 2,758
- Minnesota rank#87 of 87
- Population9,525
- Annual snowfall, NOAA normal34.9 in.
- FIPS27133
How Rock County compares
28 psf ranks #265 of 2,758 US counties with a mapped snow load (top 10%) - and #87 of 87 in Minnesota. 37.4 psf is Minnesota's typical county figure - Rock County comes in 9.4 psf under it.
Population 9,525 (FIPS 27133), roughly 43.6696°N 96.2632°W. The 40 psf ground snow load ASCE 7-22 maps here becomes 28 psf once the code's own design factors are applied.
Typical snowfall in Rock County, MN
NOAA's 30-year normal for Rock County: 34.9 in. of snow a year, from the ROCK RAPIDS, IA US station. (fresh vs. packed vs. ice explains why.)
What this Rock County figure assumes
This is a county-level reference figure for a typical heated home built to Risk Category II (ordinary residential), on a partially exposed lot - the assumptions ASCE 7-22 itself treats as the default case. A steeper roof, a fully exposed hilltop lot, an unheated structure, or a higher risk category all change the actual number.
Rock County's permit office wants an address-specific figure, not this county average - the ASCE 7 Hazard Tool is free, takes under a minute, and outputs a PDF most reviewers accept. Details: the calculation guide.