SnowLoadCheck

Benton County, WA Roof Snow Load - 15 psf

How much snow is too much for a roof in Benton County, WA?

Moderate
15 psf

15 psf: that's what ASCE 7-22 requires a typical heated home's roof in Benton County to carry. The physics-based figure alone would be 10.5 psf, but ASCE 7's own low-slope minimum (§7.3.4) sets a floor of 15 psf for flat and low-pitch roofs here, which is the number that actually governs.

Picture it, not just weigh it: 33 in. if it's fresh powder, 12 in. once it settles, or a mere 3 in. if it's ice. This is a meaningful design load - most modern-code homes handle it fine, though an addition, a carport or a flat-roofed section can be a weak spot.

Benton County at a glance

How Benton County compares

15 psf ranks #1,323 of 2,758 US counties with a mapped snow load (top 48%) - and #8 of 10 in Washington. That's 1 psf below Washington's own county-average design load of 16 psf.

Population 218,190 (FIPS 53005), roughly 46.2281°N 119.5167°W. The 15 psf ground snow load ASCE 7-22 maps here becomes 15 psf once the code's own design factors are applied.

Typical snowfall in Benton County, WA

NOAA's 30-year normal for Benton County: 3.7 in. of snow a year, from the BOARDMAN, OR US station. That station is far enough away (27.6 mi) that local snowfall - especially at a different elevation or near a lake - can run noticeably higher or lower than this figure. (fresh vs. packed vs. ice explains why.)

What this Benton 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.

Benton 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.)