SnowLoadCheck

Dorchester County, SC Roof Snow Load - 5 psf

Dorchester County, SC roof snow load, translated

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5 psf

A typical heated home in Dorchester 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.

Already snow on the roof in Dorchester County?

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Dorchester County in numbers

Where Dorchester County ranks

#39 of 46 South Carolina counties by design load, top 77% of 2,758 nationally - that's Dorchester County's spot. That's 3.8 psf below South Carolina's own county-average design load of 8.8 psf.

FIPS 45035, population 174,663, centered near 33.0822°N 80.4047°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.

Dorchester County: average annual snowfall

Dorchester County sees about 0.3 in. of snow most winters, per the GIVHANS FERRY 2 ESE, SC US station's 1991-2020 NOAA normal. See the density guide.

Read this before you use Dorchester 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.)