Onslow County, NC Roof Snow Load - 10 psf
Onslow County, NC roof snow load, translated
A typical heated home in Onslow County is designed to carry 10 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 10 psf - higher than the 7 psf the ground-load formula alone would give, and the code says use the larger one.
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. Standard residential construction handles a load this size without extra bracing; it is a modest addition on top of ordinary roof loading.
Already snow on the roof in Onslow County?
Onslow County in numbers
- Design roof snow load10 psf
- Ground snow load, ASCE 7 map10 psf
- National rank#1,681 of 2,758
- North Carolina rank#57 of 100
- Population212,954
- Annual snowfall, NOAA normal0.6 in.
- FIPS37133
Where Onslow County ranks
#57 of 100 North Carolina counties by design load, top 61% of 2,758 nationally - that's Onslow County's spot. 12.9 psf is North Carolina's typical county figure - Onslow County comes in 2.9 psf under it.
FIPS 37133, population 212,954, centered near 34.7631°N 77.4995°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.
Onslow County: average annual snowfall
Onslow County sees about 0.6 in. of snow most winters, per the NEW RIVER MCAF, NC US station's 1991-2020 NOAA normal. See the density guide.
Read this before you use Onslow 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.