Louisa County, VA Roof Snow Load - 20 psf
How much snow is too much for a roof in Louisa County, VA?
20 psf: that's what ASCE 7-22 requires a typical heated home's roof in Louisa County to carry. §7.3.4's low-slope minimum of 20 psf is what actually governs on a flat or low-pitch roof here - higher than the 17.5 psf the base ground-load formula gives.
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. 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.
Louisa County, VA: quick facts
- Design roof snow load20 psf
- Ground snow load, ASCE 7 map25 psf
- National rank#772 of 2,758
- Virginia rank#32 of 110
- Population42,109
- Annual snowfall, NOAA normal15.8 in.
- FIPS51109
How Louisa County compares
20 psf ranks #772 of 2,758 US counties with a mapped snow load (top 28%) - and #32 of 110 in Virginia. That's 1.7 psf above Virginia's own county-average design load of 18.3 psf.
Population 42,109 (FIPS 51109), roughly 37.9727°N 77.9598°W. The 25 psf ground snow load ASCE 7-22 maps here becomes 20 psf once the code's own design factors are applied.
Typical snowfall in Louisa County, VA
NOAA's 30-year normal for Louisa County: 15.8 in. of snow a year, from the LOUISA, VA US station. (fresh vs. packed vs. ice explains why.)
What this Louisa 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.
Louisa 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. See the methodology guide.