Washington County, AL Roof Snow Load - 5 psf
Washington County, AL roof snow load, translated
A typical heated home in Washington County is designed to carry 5 pounds per square foot of snow on its roof, per ASCE 7-22. §7.3.4's low-slope minimum of 5 psf is what actually governs on a flat or low-pitch roof here - higher than the 3.5 psf the base ground-load formula gives.
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. A modest addition to standard roof loading. Ordinary residential construction handles this without extra bracing.
Washington County, AL: quick facts
- Design roof snow load5 psf
- Ground snow load, ASCE 7 map5 psf
- National rank#2,336 of 2,758
- Alabama rank#47 of 67
- Population15,018
- Annual snowfall, NOAA normal0 in.
- FIPS01129
Where Washington County ranks
#47 of 67 Alabama counties by design load, top 85% of 2,758 nationally - that's Washington County's spot. 5.6 psf is Alabama's typical county figure - Washington County comes in 0.6 psf under it.
FIPS 01129, population 15,018, centered near 31.4085°N 88.2124°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.
Washington County: average annual snowfall
Washington County sees about 0 in. of snow most winters, per the JACKSON, AL US station's 1991-2020 NOAA normal. See the density guide.
Read this before you use Washington 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.)