Carroll County, MD Roof Snow Load - 21 psf

How much snow is too much for a roof in Carroll County, MD?

Picture it, not just weigh it: 46.2 in. if it's fresh powder, 16.8 in. once it settles, or a mere 4.2 in. if it's ice. 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.

Carroll County in numbers

• Design roof snow load21 psf
• Ground snow load, ASCE 7 map30 psf
• National rank#406 of 2,758
• Maryland rank#2 of 21
• Population177,108
• Annual snowfall, NOAA normal28.2 in.
• FIPS24013

How Carroll County compares

21 psf ranks #406 of 2,758 US counties with a mapped snow load (top 15%) - and #2 of 21 in Maryland. 20.1 psf is Maryland's typical county figure - Carroll County beats it by 0.9 psf.

Population 177,108 (FIPS 24013), roughly 39.5633°N 77.0153°W. The 30 psf ground snow load ASCE 7-22 maps here becomes 21 psf once the code's own design factors are applied.

Typical snowfall in Carroll County, MD

NOAA's 30-year normal for Carroll County: 28.2 in. of snow a year, from the HANOVER 4 SW, PA US station. (fresh vs. packed vs. ice explains why.)

What this Carroll 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.

Carroll 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.)