Pope County, IL Roof Snow Load - 15 psf
Pope County, IL roof snow load, translated
A typical heated home in Pope 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. Modern-code homes carry a load like this without issue; an older addition, a carport, or any flat-roofed section is where it is worth checking first.
Pope County in numbers
- Design roof snow load15 psf
- Ground snow load, ASCE 7 map15 psf
- National rank#1,622 of 2,758
- Illinois rank#101 of 102
- Population3,703
- Annual snowfall, NOAA normal3.1 in.
- FIPS17151
Where Pope County ranks
#101 of 102 Illinois counties by design load, top 59% of 2,758 nationally - that's Pope County's spot. That's 4.3 psf below Illinois's own county-average design load of 19.3 psf.
FIPS 17151, population 3,703, centered near 37.4172°N 88.5424°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.
Pope County: average annual snowfall
Pope County sees about 3.1 in. of snow most winters, per the BROOKPORT DAM 52, IL US station's 1991-2020 NOAA normal. See the density guide.
Read this before you use Pope 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. See the methodology guide.