Lawrence County, TN Roof Snow Load - 10 psf
Lawrence County, TN roof snow load, translated
A typical heated home in Lawrence County is designed to carry 10 pounds per square foot of snow on its roof, per ASCE 7-22. §7.3.4's low-slope minimum of 10 psf is what actually governs on a flat or low-pitch roof here - higher than the 7 psf the base ground-load formula gives.
On a roof that means 22 in. of fresh snow, 8 in. once it packs down, or 2 in. of solid ice - three very different piles for the same load. A modest addition to standard roof loading. Ordinary residential construction handles this without extra bracing.
Lawrence County at a glance
- Design roof snow load10 psf
- Ground snow load, ASCE 7 map10 psf
- National rank#1,789 of 2,758
- Tennessee rank#37 of 95
- Population46,467
- Annual snowfall, NOAA normal1.9 in.
- FIPS47099
Where Lawrence County ranks
#37 of 95 Tennessee counties by design load, top 65% of 2,758 nationally - that's Lawrence County's spot. Tennessee counties average 10.3 psf; Lawrence County runs 0.3 psf lower than that.
FIPS 47099, population 46,467, centered near 35.2205°N 87.3965°W. ASCE 7's underlying ground snow load here is 10 psf before the code's exposure and importance factors bring it to the 10 psf design figure above.
Lawrence County: average annual snowfall
Lawrence County sees about 1.9 in. of snow most winters, per the PULASKI WWTP, TN US station's 1991-2020 NOAA normal. See the density guide.
Read this before you use Lawrence County's figure
The figure above assumes the case ASCE 7-22 treats as typical: a heated, ordinary-occupancy home on a partially exposed site. Change any of those - exposure, heating, roof pitch, occupancy category - and the real design number moves.
A building permit needs the number at your exact address, not the county average - the free ASCE 7 Hazard Tool returns that from your coordinates in about a minute and produces a PDF a plan reviewer will accept. Details: the calculation guide.