Lane County, OR Roof Snow Load - 10 psf
Lane County, OR roof snow load, translated
A typical heated home in Lane County is designed to carry 10 pounds per square foot of snow on its roof, per ASCE 7-22. 7 psf is what the ground-load formula alone gives; Lane County's 10 psf low-slope minimum (§7.3.4) beats it, so that figure is the one that governs on flat and low-pitch roofs.
On a roof that means 22 in. of fresh snow, 8 in. once it packs down, or 2 in. of solid ice - three very different piles for the same load. Standard residential construction handles a load this size without extra bracing; it is a modest addition on top of ordinary roof loading.
Lane County, OR: quick facts
- Design roof snow load10 psf
- Ground snow load, ASCE 7 map10 psf
- National rank#1,663 of 2,758
- Oregon rank#7 of 15
- Population382,396
- Annual snowfall, NOAA normal0.6 in.
- FIPS41039
Where Lane County ranks
#7 of 15 Oregon counties by design load, top 60% of 2,758 nationally - that's Lane County's spot. 12 psf is Oregon's typical county figure - Lane County comes in 2 psf under it.
FIPS 41039, population 382,396, centered near 43.9283°N 122.8976°W. ASCE 7's underlying ground snow load here is 10 psf before the code's exposure and importance factors bring it to the 10 psf design figure above.
Lane County: average annual snowfall
Lane County sees about 0.6 in. of snow most winters, per the LOOKOUT PT DAM, OR US station's 1991-2020 NOAA normal. See the density guide.
Read this before you use Lane 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.