Armstrong County, TX Roof Snow Load - 15 psf
Armstrong County, TX roof snow load, translated
A typical heated home in Armstrong County is designed to carry 15 pounds per square foot of snow on its roof, per ASCE 7-22. §7.3.4's low-slope minimum of 15 psf is what actually governs on a flat or low-pitch roof here - higher than the 10.5 psf the base ground-load formula gives.
On a roof that means 33 in. of fresh snow, 12 in. once it packs down, or 3 in. of solid ice - three very different piles for the same load. A meaningful design load. Most homes built to modern code handle it, but additions, carports, and flat-roofed sections are worth a second look.
Armstrong County, TX: quick facts
- Design roof snow load15 psf
- Ground snow load, ASCE 7 map15 psf
- National rank#1,643 of 2,758
- Texas rank#26 of 254
- Population1,809
- Annual snowfall, NOAA normal3.5 in.
- FIPS48011
Where Armstrong County ranks
#26 of 254 Texas counties by design load, top 60% of 2,758 nationally - that's Armstrong County's spot. 5.4 psf is Texas's typical county figure - Armstrong County beats it by 9.6 psf.
FIPS 48011, population 1,809, centered near 34.9642°N 101.3566°W. ASCE 7's underlying ground snow load here is 15 psf before the code's exposure and importance factors bring it to the 15 psf design figure above.
Armstrong County: average annual snowfall
Armstrong County sees about 3.5 in. of snow most winters, per the CLARENDON, TX US station's 1991-2020 NOAA normal. 26.5 mi is a real gap between Armstrong County and its nearest reporting station, so local snowfall can diverge from this figure, especially near elevation changes. See the density guide.
Read this before you use Armstrong 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. See the methodology guide.