Gilliam County, OR Roof Snow Load - 20 psf
How much snow is too much for a roof in Gilliam County, OR?
20 psf: that's what ASCE 7-22 requires a typical heated home's roof in Gilliam County to carry. Flat and low-pitch roofs in Gilliam 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.
Picture it, not just weigh it: 44 in. if it's fresh powder, 16 in. once it settles, or a mere 4 in. if it's ice. 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.
Gilliam County at a glance
- Design roof snow load20 psf
- Ground snow load, ASCE 7 map20 psf
- National rank#1,277 of 2,758
- Oregon rank#3 of 15
- Population1,971
- Annual snowfall, NOAA normal25.5 in.
- FIPS41021
How Gilliam County compares
20 psf ranks #1,277 of 2,758 US counties with a mapped snow load (top 46%) - and #3 of 15 in Oregon. 12 psf is Oregon's typical county figure - Gilliam County beats it by 8 psf.
Population 1,971 (FIPS 41021), roughly 45.383°N 120.2762°W. The 20 psf ground snow load ASCE 7-22 maps here becomes 20 psf once the code's own design factors are applied.
Typical snowfall in Gilliam County, OR
NOAA's 30-year normal for Gilliam County: 25.5 in. of snow a year, from the CONDON, OR US station. (fresh vs. packed vs. ice explains why.)
What this Gilliam County figure assumes
This is a county-level reference figure for a typical heated home built to Risk Category II (ordinary residential), on a partially exposed lot - the assumptions ASCE 7-22 itself treats as the default case. A steeper roof, a fully exposed hilltop lot, an unheated structure, or a higher risk category all change the actual number.
Gilliam County's permit office wants an address-specific figure, not this county average - the ASCE 7 Hazard Tool is free, takes under a minute, and outputs a PDF most reviewers accept. (How this figure is calculated.)