Eaton County, MI Roof Snow Load - 21 psf
Eaton County, MI roof snow load, translated
A typical heated home in Eaton County is designed to carry 21 pounds per square foot of snow on its roof, per ASCE 7-22.
On a roof that means 46.2 in. of fresh snow, 16.8 in. once it packs down, or 4.2 in. of solid ice - three very different piles for the same load. Modern-code homes carry a load like this without issue; an older addition, a carport, or any flat-roofed section is where it is worth checking first.
Eaton County in numbers
- Design roof snow load21 psf
- Ground snow load, ASCE 7 map30 psf
- National rank#417 of 2,758
- Michigan rank#52 of 70
- Population109,494
- Annual snowfall, NOAA normal38.1 in.
- FIPS26045
Where Eaton County ranks
#52 of 70 Michigan counties by design load, top 15% of 2,758 nationally - that's Eaton County's spot. 31.7 psf is Michigan's typical county figure - Eaton County comes in 10.7 psf under it.
FIPS 26045, population 109,494, centered near 42.5895°N 84.8465°W. ASCE 7's underlying ground snow load here is 30 psf before the code's exposure and importance factors bring it to the 21 psf design figure above.
Eaton County: average annual snowfall
Eaton County sees about 38.1 in. of snow most winters, per the CHARLOTTE, MI US station's 1991-2020 NOAA normal. See the density guide.
Read this before you use Eaton 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.