Middlesex County, MA Roof Snow Load - 35 psf
Middlesex County, MA roof snow load, translated
A typical heated home in Middlesex County is designed to carry 35 pounds per square foot of snow on its roof, per ASCE 7-22.
On a roof that means 77 in. of fresh snow, 28 in. once it packs down, or 7 in. of solid ice - three very different piles for the same load. A load this size is a serious structural matter; pre-modern-code homes and low-slope or flat-roofed sections are the ones most worth an inspection.
Middlesex County at a glance
- Design roof snow load35 psf
- Ground snow load, ASCE 7 map50 psf
- National rank#87 of 2,758
- Massachusetts rank#1 of 14
- Population1,668,956
- Annual snowfall, NOAA normal45.7 in.
- FIPS25017
Where Middlesex County ranks
#1 of 14 Massachusetts counties by design load, top 3% of 2,758 nationally - that's Middlesex County's spot. 27.6 psf is Massachusetts's typical county figure - Middlesex County beats it by 7.4 psf.
FIPS 25017, population 1,668,956, centered near 42.4817°N 71.3949°W. ASCE 7's underlying ground snow load here is 50 psf before the code's exposure and importance factors bring it to the 35 psf design figure above.
Middlesex County: average annual snowfall
Middlesex County sees about 45.7 in. of snow most winters, per the NATICK, MA US station's 1991-2020 NOAA normal. See the density guide.
Read this before you use Middlesex 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.