SnowLoadCheck

King William County, VA Roof Snow Load - 20 psf

How much snow is too much for a roof in King William County, VA?

Moderate
20 psf

20 psf: that's what ASCE 7-22 requires a typical heated home's roof in King William County to carry. Flat and low-pitch roofs in King William County are actually governed by ASCE 7's §7.3.4 minimum of 20 psf, not the 14 psf the ground-load formula alone would produce.

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.

Already snow on the roof in King William County?

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King William County in numbers

How King William County compares

20 psf ranks #970 of 2,758 US counties with a mapped snow load (top 35%) - and #54 of 110 in Virginia. Virginia counties average 18.3 psf; King William County runs 1.7 psf higher than that.

Population 19,232 (FIPS 51101), roughly 37.7083°N 77.0911°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 King William County, VA

NOAA's 30-year normal for King William County: 11.5 in. of snow a year, from the CORBIN, VA US station. Worth noting: the nearest station reporting snowfall normals sits 37.5 mi from King William County's center, so treat this as a regional figure rather than an exact one. (fresh vs. packed vs. ice explains why.)

What this King William 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.

King William 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.)