Sullivan County, TN Roof Snow Load - 15 psf
How much snow is too much for a roof in Sullivan County, TN?
15 psf: that's what ASCE 7-22 requires a typical heated home's roof in Sullivan 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.
Sullivan County in numbers
- Design roof snow load15 psf
- Ground snow load, ASCE 7 map15 psf
- National rank#1,330 of 2,758
- Tennessee rank#2 of 95
- Population162,703
- Annual snowfall, NOAA normal9.2 in.
- FIPS47163
How Sullivan County compares
15 psf ranks #1,330 of 2,758 US counties with a mapped snow load (top 48%) - and #2 of 95 in Tennessee. 10.3 psf is Tennessee's typical county figure - Sullivan County beats it by 4.7 psf.
Population 162,703 (FIPS 47163), roughly 36.5097°N 82.3013°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 Sullivan County, TN
NOAA's 30-year normal for Sullivan County: 9.2 in. of snow a year, from the BRISTOL TRI CITY AP, TN US station. (fresh vs. packed vs. ice explains why.)
What this Sullivan 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.
Sullivan 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.