Columbia County, OR Roof Snow Load - 10 psf
Columbia County, OR: your roof's ASCE 7 snow number, in plain English
Columbia County's roofs are built to hold 10 psf of snow, the ASCE 7-22 figure a permit reviewer checks first. ASCE 7's low-slope-roof minimum (§7.3.4) raises the governing figure to 10 psf - higher than the 7 psf the ground-load formula alone would give, and the code says use the larger one.
In depth, not weight: that's roughly 22 inches of fresh, light snow, 8 inches of old, settled snow, or as little as 2 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. A modest addition to standard roof loading. Ordinary residential construction handles this without extra bracing.
Already snow on the roof in Columbia County?
Columbia County in numbers
- Design roof snow load10 psf
- Ground snow load, ASCE 7 map10 psf
- National rank#1,773 of 2,758
- Oregon rank#9 of 15
- Population54,063
- Annual snowfall, NOAA normal1.1 in.
- FIPS41009
Columbia County by the numbers
Nationally that's #1,773 out of 2,758 rated counties, the top 64%; within Oregon alone, Columbia County ranks #9 of 15. That's 2 psf below Oregon's own county-average design load of 12 psf.
Columbia County, FIPS 41009, is home to 54,063 people near 45.9419°N 123.0811°W. Its 10 psf ground snow load figure is the map value; 10 psf is what a roof is actually designed for.
Columbia County's snowfall, most winters
1.1 in. a year: that's Columbia County's NOAA 1991-2020 snowfall normal, measured at VERNONIA #2, OR US (7.5 mi away). See the density guide.
Before you rely on Columbia County's number
Treat the Columbia 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. See the methodology guide.