Wake County, NC Roof Snow Load - 15 psf
Wake County, NC roof snow load, translated
A typical heated home in Wake 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. A meaningful design load. Most homes built to modern code handle it, but additions, carports, and flat-roofed sections are worth a second look.
Wake County at a glance
- Design roof snow load15 psf
- Ground snow load, ASCE 7 map15 psf
- National rank#1,306 of 2,758
- North Carolina rank#9 of 100
- Population1,232,444
- Annual snowfall, NOAA normal4.5 in.
- FIPS37183
Where Wake County ranks
#9 of 100 North Carolina counties by design load, top 47% of 2,758 nationally - that's Wake County's spot. North Carolina counties average 12.9 psf; Wake County runs 2.1 psf higher than that.
FIPS 37183, population 1,232,444, centered near 35.7898°N 78.6506°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.
Wake County: average annual snowfall
Wake County sees about 4.5 in. of snow most winters, per the RALEIGH STATE UNIV, NC US station's 1991-2020 NOAA normal. See the density guide.
Read this before you use Wake 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.)