San Juan County, NM Roof Snow Load - 5 psf
How much snow is too much for a roof in San Juan County, NM?
5 psf: that's what ASCE 7-22 requires a typical heated home's roof in San Juan County to carry. 3.5 psf is what the ground-load formula alone gives; San Juan County's 5 psf low-slope minimum (§7.3.4) beats it, so that figure is the one that governs on flat and low-pitch roofs.
Picture it, not just weigh it: 11 in. if it's fresh powder, 4 in. once it settles, or a mere 1 in. if it's ice. This is a modest add-on to standard roof loading - ordinary residential construction carries it without extra bracing.
San Juan County at a glance
- Design roof snow load5 psf
- Ground snow load, ASCE 7 map5 psf
- National rank#2,132 of 2,758
- New Mexico rank#13 of 27
- Population120,817
- Annual snowfall, NOAA normal8.6 in.
- FIPS35045
How San Juan County compares
5 psf ranks #2,132 of 2,758 US counties with a mapped snow load (top 77%) - and #13 of 27 in New Mexico. New Mexico counties average 6.9 psf; San Juan County runs 1.9 psf lower than that.
Population 120,817 (FIPS 35045), roughly 36.5116°N 108.3246°W. The 5 psf ground snow load ASCE 7-22 maps here becomes 5 psf once the code's own design factors are applied.
Typical snowfall in San Juan County, NM
NOAA's 30-year normal for San Juan County: 8.6 in. of snow a year, from the FARMINGTON AG SCI CNT, NM US station. (fresh vs. packed vs. ice explains why.)
What this San Juan 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.
San Juan 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.)