Belknap County, NH Roof Snow Load - 56 psf
Belknap County, NH roof snow load, translated
A typical heated home in Belknap County is designed to carry 56 pounds per square foot of snow on its roof, per ASCE 7-22.
On a roof that means 123.2 in. of fresh snow, 44.8 in. once it packs down, or 11.2 in. of solid ice - three very different piles for the same load. Among the highest mapped design loads in the country outside case-study terrain. Roof snow removal and periodic structural inspection are standard practice at this load.
Belknap County at a glance
- Design roof snow load56 psf
- Ground snow load, ASCE 7 map80 psf
- National rank#7 of 2,758
- New Hampshire rank#2 of 4
- Population65,257
- Annual snowfall, NOAA normal68.3 in.
- FIPS33001
Where Belknap County ranks
#2 of 4 New Hampshire counties by design load, top 1% of 2,758 nationally - that's Belknap County's spot. That's 5.2 psf above New Hampshire's own county-average design load of 50.8 psf.
FIPS 33001, population 65,257, centered near 43.5191°N 71.4254°W. ASCE 7's underlying ground snow load here is 80 psf before the code's exposure and importance factors bring it to the 56 psf design figure above.
Belknap County: average annual snowfall
Belknap County sees about 68.3 in. of snow most winters, per the PLYMOUTH, NH US station's 1991-2020 NOAA normal. See the density guide.
Read this before you use Belknap 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. (How this figure is calculated.)