Grayson County, VA Roof Snow Load - 20 psf
How much snow is too much for a roof in Grayson County, VA?
20 psf: that's what ASCE 7-22 requires a typical heated home's roof in Grayson County to carry. Flat and low-pitch roofs in Grayson 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. A meaningful design load. Most homes built to modern code handle it, but additions, carports, and flat-roofed sections are worth a second look.
Grayson County at a glance
- Design roof snow load20 psf
- Ground snow load, ASCE 7 map20 psf
- National rank#1,023 of 2,758
- Virginia rank#65 of 110
- Population15,265
- Annual snowfall, NOAA normal8.5 in.
- FIPS51077
How Grayson County compares
20 psf ranks #1,023 of 2,758 US counties with a mapped snow load (top 37%) - and #65 of 110 in Virginia. 18.3 psf is Virginia's typical county figure - Grayson County beats it by 1.7 psf.
Population 15,265 (FIPS 51077), roughly 36.6522°N 81.2153°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 Grayson County, VA
NOAA's 30-year normal for Grayson County: 8.5 in. of snow a year, from the TROUT DALE 3 SSE, VA US station. (fresh vs. packed vs. ice explains why.)
What this Grayson 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.
Grayson 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.