Sullivan County, IN Roof Snow Load - 20 psf
Sullivan County, IN roof snow load, translated
A typical heated home in Sullivan County is designed to carry 20 pounds per square foot of snow on its roof, per ASCE 7-22. The physics-based figure alone would be 14 psf, but ASCE 7's own low-slope minimum (§7.3.4) sets a floor of 20 psf for flat and low-pitch roofs here, which is the number that actually governs.
On a roof that means 44 in. of fresh snow, 16 in. once it packs down, or 4 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.
Sullivan County at a glance
- Design roof snow load20 psf
- Ground snow load, ASCE 7 map20 psf
- National rank#949 of 2,758
- Indiana rank#58 of 89
- Population20,768
- Annual snowfall, NOAA normal15.1 in.
- FIPS18153
Where Sullivan County ranks
#58 of 89 Indiana counties by design load, top 34% of 2,758 nationally - that's Sullivan County's spot. That's 0.7 psf above Indiana's own county-average design load of 19.3 psf.
FIPS 18153, population 20,768, centered near 39.0892°N 87.4158°W. ASCE 7's underlying ground snow load here is 20 psf before the code's exposure and importance factors bring it to the 20 psf design figure above.
Sullivan County: average annual snowfall
Sullivan County sees about 15.1 in. of snow most winters, per the FARMERSBURG TV-2, IN US station's 1991-2020 NOAA normal. See the density guide.
Read this before you use Sullivan 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.