Jefferson County, IN Roof Snow Load - 20 psf
Jefferson County, IN roof snow load, translated
A typical heated home in Jefferson County is designed to carry 20 pounds per square foot of snow on its roof, per ASCE 7-22. Flat and low-pitch roofs in Jefferson County are actually governed by ASCE 7's §7.3.4 minimum of 20 psf, not the 14 psf the ground-load formula alone would produce.
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. A meaningful design load. Most homes built to modern code handle it, but additions, carports, and flat-roofed sections are worth a second look.
Jefferson County at a glance
- Design roof snow load20 psf
- Ground snow load, ASCE 7 map20 psf
- National rank#843 of 2,758
- Indiana rank#41 of 89
- Population32,921
- Annual snowfall, NOAA normal11.9 in.
- FIPS18077
Where Jefferson County ranks
#41 of 89 Indiana counties by design load, top 31% of 2,758 nationally - that's Jefferson County's spot. 19.3 psf is Indiana's typical county figure - Jefferson County beats it by 0.7 psf.
FIPS 18077, population 32,921, centered near 38.7836°N 85.4401°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.
Jefferson County: average annual snowfall
Jefferson County sees about 11.9 in. of snow most winters, per the DEPUTY 1 WNW, IN US station's 1991-2020 NOAA normal. See the density guide.
Read this before you use Jefferson 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.)