Barnwell County, SC Roof Snow Load - 5 psf
Barnwell County, SC roof snow load, translated
A typical heated home in Barnwell County is designed to carry 5 pounds per square foot of snow on its roof, per ASCE 7-22. 3.5 psf is what the ground-load formula alone gives; Barnwell County's 5 psf low-slope minimum (§7.3.4) beats it, so that figure is the one that governs on flat and low-pitch roofs.
On a roof that means 11 in. of fresh snow, 4 in. once it packs down, or 1 in. of solid ice - three very different piles for the same load. This is a modest add-on to standard roof loading - ordinary residential construction carries it without extra bracing.
Barnwell County in numbers
- Design roof snow load5 psf
- Ground snow load, ASCE 7 map5 psf
- National rank#2,295 of 2,758
- South Carolina rank#43 of 46
- Population20,495
- Annual snowfall, NOAA normal0.7 in.
- FIPS45011
Where Barnwell County ranks
#43 of 46 South Carolina counties by design load, top 83% of 2,758 nationally - that's Barnwell County's spot. That's 3.8 psf below South Carolina's own county-average design load of 8.8 psf.
FIPS 45011, population 20,495, centered near 33.2606°N 81.4342°W. ASCE 7's underlying ground snow load here is 5 psf before the code's exposure and importance factors bring it to the 5 psf design figure above.
Barnwell County: average annual snowfall
Barnwell County sees about 0.7 in. of snow most winters, per the AIKEN 5SE, SC US station's 1991-2020 NOAA normal. See the density guide.
Read this before you use Barnwell 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. (How this figure is calculated.)