SnowLoadCheck

Butler County, PA Roof Snow Load - 20 psf

Butler County, PA: your roof's ASCE 7 snow number, in plain English

Moderate
20 psf

Butler County's roofs are built to hold 20 psf of snow, the ASCE 7-22 figure a permit reviewer checks first. 17.5 psf is what the ground-load formula alone gives; Butler County's 20 psf low-slope minimum (§7.3.4) beats it, so that figure is the one that governs on flat and low-pitch roofs.

In depth, not weight: that's roughly 44 inches of fresh, light snow, 16 inches of old, settled snow, or as little as 4 inches of solid ice - snow that heavy is rare here but ice from a freeze-thaw cycle adds up far faster than the depth suggests. 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.

Butler County, PA: quick facts

Butler County by the numbers

Nationally that's #586 out of 2,758 rated counties, the top 21%; within Pennsylvania alone, Butler County ranks #31 of 38. Pennsylvania counties average 20.9 psf; Butler County runs 0.9 psf lower than that.

Butler County, FIPS 42019, is home to 199,341 people near 40.9138°N 79.919°W. Its 25 psf ground snow load figure is the map value; 20 psf is what a roof is actually designed for.

Butler County's snowfall, most winters

27.5 in. a year: that's Butler County's NOAA 1991-2020 snowfall normal, measured at NEW CASTLE 1 N, PA US (24.2 mi away). See the density guide.

Before you rely on Butler County's number

Treat the Butler County figure as a starting point, not a final answer: it assumes standard occupancy, a heated structure and a moderately sheltered site, per ASCE 7-22's own defaults. Exposed terrain, an unheated building or a steeper roof all shift the real number.

For a real application, skip the county number and go straight to the ASCE 7 Hazard Tool - enter your coordinates and it returns a site-specific figure a plan reviewer will recognize. Details: the calculation guide.