Polk County, TN Roof Snow Load - 10 psf
How much snow is too much for a roof in Polk County, TN?
10 psf: that's what ASCE 7-22 requires a typical heated home's roof in Polk County to carry. Flat and low-pitch roofs in Polk County are actually governed by ASCE 7's §7.3.4 minimum of 10 psf, not the 7 psf the ground-load formula alone would produce.
Picture it, not just weigh it: 22 in. if it's fresh powder, 8 in. once it settles, or a mere 2 in. if it's ice. A modest addition to standard roof loading. Ordinary residential construction handles this without extra bracing.
Polk County at a glance
- Design roof snow load10 psf
- Ground snow load, ASCE 7 map10 psf
- National rank#1,921 of 2,758
- Tennessee rank#72 of 95
- Population18,338
- Annual snowfall, NOAA normal3.6 in.
- FIPS47139
How Polk County compares
10 psf ranks #1,921 of 2,758 US counties with a mapped snow load (top 70%) - and #72 of 95 in Tennessee. 10.3 psf is Tennessee's typical county figure - Polk County comes in 0.3 psf under it.
Population 18,338 (FIPS 47139), roughly 35.1094°N 84.5411°W. The 10 psf ground snow load ASCE 7-22 maps here becomes 10 psf once the code's own design factors are applied.
Typical snowfall in Polk County, TN
NOAA's 30-year normal for Polk County: 3.6 in. of snow a year, from the ATHENS, TN US station. (fresh vs. packed vs. ice explains why.)
What this Polk 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.
Polk 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.