Guilford County, NC Roof Snow Load - 15 psf
Guilford County, NC roof snow load, translated
A typical heated home in Guilford County is designed to carry 15 pounds per square foot of snow on its roof, per ASCE 7-22. Flat and low-pitch roofs in Guilford County are actually governed by ASCE 7's §7.3.4 minimum of 15 psf, not the 10.5 psf the ground-load formula alone would produce.
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. A meaningful design load. Most homes built to modern code handle it, but additions, carports, and flat-roofed sections are worth a second look.
Guilford County, NC: quick facts
- Design roof snow load15 psf
- Ground snow load, ASCE 7 map15 psf
- National rank#1,310 of 2,758
- North Carolina rank#10 of 100
- Population558,816
- Annual snowfall, NOAA normal1.9 in.
- FIPS37081
Where Guilford County ranks
#10 of 100 North Carolina counties by design load, top 47% of 2,758 nationally - that's Guilford County's spot. That's 2.1 psf above North Carolina's own county-average design load of 12.9 psf.
FIPS 37081, population 558,816, centered near 36.0791°N 79.7887°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.
Guilford County: average annual snowfall
Guilford County sees about 1.9 in. of snow most winters, per the HIGH PT, NC US station's 1991-2020 NOAA normal. See the density guide.
Read this before you use Guilford 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.