Alamance County, NC Roof Snow Load - 15 psf
Alamance County, NC roof snow load, translated
A typical heated home in Alamance County is designed to carry 15 pounds per square foot of snow on its roof, per ASCE 7-22. ASCE 7's low-slope-roof minimum (§7.3.4) raises the governing figure to 15 psf - higher than the 10.5 psf the ground-load formula alone would give, and the code says use the larger one.
On a roof that means 33 in. of fresh snow, 12 in. once it packs down, or 3 in. of solid ice - three very different piles for the same load. Modern-code homes carry a load like this without issue; an older addition, a carport, or any flat-roofed section is where it is worth checking first.
Alamance County, NC: quick facts
- Design roof snow load15 psf
- Ground snow load, ASCE 7 map15 psf
- National rank#1,326 of 2,758
- North Carolina rank#16 of 100
- Population183,040
- Annual snowfall, NOAA normal1.8 in.
- FIPS37001
Where Alamance County ranks
#16 of 100 North Carolina counties by design load, top 48% of 2,758 nationally - that's Alamance County's spot. 12.9 psf is North Carolina's typical county figure - Alamance County beats it by 2.1 psf.
FIPS 37001, population 183,040, centered near 36.044°N 79.4006°W. ASCE 7's underlying ground snow load here is 15 psf before the code's exposure and importance factors bring it to the 15 psf design figure above.
Alamance County: average annual snowfall
Alamance County sees about 1.8 in. of snow most winters, per the GRAHAM 2 ENE, NC US station's 1991-2020 NOAA normal. See the density guide.
Read this before you use Alamance 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.