Saline County, IL Roof Snow Load - 15 psf
Saline County, IL roof snow load, translated
A typical heated home in Saline County is designed to carry 15 pounds per square foot of snow on its roof, per ASCE 7-22. §7.3.4's low-slope minimum of 15 psf is what actually governs on a flat or low-pitch roof here - higher than the 10.5 psf the base ground-load formula gives.
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. This is a meaningful design load - most modern-code homes handle it fine, though an addition, a carport or a flat-roofed section can be a weak spot.
Saline County at a glance
- Design roof snow load15 psf
- Ground snow load, ASCE 7 map15 psf
- National rank#1,448 of 2,758
- Illinois rank#92 of 102
- Population22,826
- Annual snowfall, NOAA normal13.3 in.
- FIPS17165
Where Saline County ranks
#92 of 102 Illinois counties by design load, top 53% of 2,758 nationally - that's Saline County's spot. 19.3 psf is Illinois's typical county figure - Saline County comes in 4.3 psf under it.
FIPS 17165, population 22,826, centered near 37.7515°N 88.545°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.
Saline County: average annual snowfall
Saline County sees about 13.3 in. of snow most winters, per the MCLEANSBORO, IL US station's 1991-2020 NOAA normal. See the density guide.
Read this before you use Saline 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.)