SnowLoadCheck

Des Moines County, IA Roof Snow Load - 20 psf

How much snow is too much for a roof in Des Moines County, IA?

Moderate
20 psf

20 psf: that's what ASCE 7-22 requires a typical heated home's roof in Des Moines County to carry. 14 psf is what the ground-load formula alone gives; Des Moines County's 20 psf low-slope minimum (§7.3.4) beats it, so that figure is the one that governs on flat and low-pitch roofs.

Picture it, not just weigh it: 44 in. if it's fresh powder, 16 in. once it settles, or a mere 4 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.

Snow on Des Moines County's roofs right now?

in. of

Des Moines County in numbers

How Des Moines County compares

20 psf ranks #791 of 2,758 US counties with a mapped snow load (top 29%) - and #54 of 99 in Iowa. 21.7 psf is Iowa's typical county figure - Des Moines County comes in 1.7 psf under it.

Population 38,411 (FIPS 19057), roughly 40.9153°N 91.1869°W. The 20 psf ground snow load ASCE 7-22 maps here becomes 20 psf once the code's own design factors are applied.

Typical snowfall in Des Moines County, IA

NOAA's 30-year normal for Des Moines County: 21.8 in. of snow a year, from the BURLINGTON 2S, IA US station. (fresh vs. packed vs. ice explains why.)

What this Des Moines 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.

Des Moines 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. (How this figure is calculated.)