Snow Guards Calculator

Based on Orima method. For standing seam metal roofs in Canada & USA.
Imperial (psf, ft, in) Metric (kN/m², m)
Mode sets input units only. Values are not converted automatically when switching modes.

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Snow Load Zoning — North America (schematic)

Schematic snow load zoning for quick orientation. Use this as a helper together with the Snow Guards Calculator above. Always confirm design values with NBCC (Canada), ASCE 7 (USA) and local building officials.

CANADA — NBCC (schematic ground snow load zones, Pg)
Indicative ground snow load ranges for major Canadian regions. Use NBCC climatic data for final design.
BC Coast
Vancouver, Victoria, coastal BC
Typical Pg: 15–25 psf (≈0.7–1.2 kN/m²)
BC Interior & Rockies
Kelowna, Kamloops, Revelstoke
Typical Pg: 30–80+ psf (≈1.5–4.0+ kN/m²)
Prairies (AB, SK, MB)
Calgary, Edmonton, Regina, Winnipeg
Typical Pg: 25–45 psf (≈1.2–2.2 kN/m²)
Southern ON & QC corridor
Toronto, Ottawa, Montréal, Québec City
Typical Pg: 20–40 psf (≈1.0–1.9 kN/m²)
Atlantic Canada
Halifax, St. John’s and coastal Atlantic
Typical Pg: 35–60 psf (≈1.7–3.0 kN/m²)
USA — ASCE 7 (schematic ground snow load zones, Pg)
Simplified ASCE 7 style zoning. Always check official ASCE 7 maps and local amendments.
Southern & coastal states
TX, FL, GA, CA lowlands
Typical Pg: < 20 psf
Central / Mid-Atlantic
MO, KY, VA, NJ, lower Midwest
Typical Pg: 20–35 psf
Snow belt & New England
NY, PA, MI, MA, VT, NH
Typical Pg: 30–60 psf
Rockies
CO, UT, WY, MT highlands
Typical Pg: 40–80 psf+
Alaska (high)
Interior & mountain regions
Typical Pg: 80–150+ psf
Low (< 20 psf) Medium (20–40 psf) High (40–80 psf) Extreme (> 80 psf)

Typical Ground Snow Loads — Canada (NBCC-based, schematic)

The table below shows typical NBCC ground snow load ranges (Pg) for major Canadian regions. Values are rounded and schematic — always refer to NBCC climatic data (Appendix C) and local provisions.

Region (Canada) Typical cities / examples Typical Pg (psf) Approx. Pg (kN/m²)
BC Coast Vancouver, Victoria, Nanaimo 15–25 psf 0.7–1.2 kN/m²
BC Interior & Rockies Kelowna, Kamloops, Revelstoke, Prince George 30–80+ psf 1.5–4.0+ kN/m²
Prairies (AB, SK, MB) Calgary, Edmonton, Saskatoon, Regina, Winnipeg 25–45 psf 1.2–2.2 kN/m²
Southern Ontario corridor Windsor, London, Hamilton, Toronto 20–35 psf 1.0–1.7 kN/m²
Ottawa / Montréal / Québec City Ottawa, Montréal, Québec City region 30–45 psf 1.5–2.2 kN/m²
Atlantic Canada Halifax, Moncton, St. John’s 35–60 psf 1.7–3.0 kN/m²

Typical Ground Snow Loads — USA (ASCE 7 schematic)

Schematic ASCE 7-style ground snow load ranges for typical regions in the United States. Always check the current ASCE 7 maps, local amendments and state building codes for project design.

Region (USA) Typical states / examples Typical Pg (psf) Approx. Pg (kN/m²)
Southern & coastal states TX, FL, GA, AL, LA, coastal CA < 20 psf < 1.0 kN/m²
Central / Mid-Atlantic MO, KY, TN, VA, NC, NJ, lower Midwest 20–35 psf 1.0–1.7 kN/m²
Snow belt / Great Lakes Upstate NY, PA, OH, MI, WI, MN 25–50 psf 1.2–2.4 kN/m²
New England MA, VT, NH, ME, northern CT/RI 30–60 psf 1.5–2.9 kN/m²
Rocky Mountains CO, UT, WY, MT high elevation 40–80+ psf 2.0–3.8+ kN/m²
Alaska (interior & mountains) Interior Alaska, mountain regions 80–150+ psf 3.8–7.2+ kN/m²

Canada & USA full list and conversions will be available in “Snow Load Reference Guide — Canada & USA (PDF)”. Values here are indicative only.

This schematic guide is provided by Safe Roof Experts to support snow guard design. Always use official NBCC, ASCE 7, manufacturer instructions and engineering judgment when sizing snow retention systems.

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