Roof Snow Load Calculator
Enter your roof's dimensions, pitch, and roofing material. Results update instantly — the calculator uses the Tulsa ground snow load of 20 psf per the International Building Code (IBC Figure 1608.2).
Total roof load (dead load + snow load)
Dead load
0 lbs total
Snow load
0 lbs total
Total weight on roof
Dead + snow, across the full surface
Roof surface area
Footprint × pitch factor
How the snow load was calculated
Ground snow load (pg) = 20 psf (Tulsa, OK — IBC Figure 1608.2).
The safety threshold uses the typical Tulsa-area residential design load of 40 psf total (20 psf dead + 20 psf live/snow). This is an estimate for homeowner planning — a licensed professional must verify actual structural capacity.
How Roof Loads Work: What's Safe for a Tulsa Roof
Dead load is the permanent weight of the roof itself — shingles, underlayment, decking, and framing. Snow load is a live (temporary) load: the weight of accumulated snow and ice. Building codes add them together and compare the total against the roof's design capacity, because the worst case is a fully loaded roof during a heavy Oklahoma winter storm.
The International Building Code sets the ground snow load (pg) for Tulsa, Oklahoma at 20 psf (IBC Figure 1608.2, based on ASCE 7 snow maps). For a typical sloped shingle roof, the code converts that ground load into a roof snow load of about 14 psf (0.7 × exposure × thermal × importance factors). Flat and low-slope roofs get a 20 psf minimum per ASCE 7, and very steep pitches shed snow, so their snow load drops.
Most Tulsa-area homes are designed to a 40 psf total load — 20 psf dead plus 20 psf live. A typical asphalt shingle roof comes in around 29 psf total, which is why Oklahoma roofs handle normal winters without issue. The situations that deserve attention: heavy tile or slate roofing, flat roofs (ponding and drifting), older homes with undersized framing, and snow drifts piling against walls, valleys, and mechanical units.
| Roofing material | Typical dead load | Notes |
|---|---|---|
| Asphalt shingle | 15 psf | Most common in Tulsa — includes framing + shingles |
| Metal | 10 psf | Lightest common option — great for snow shedding |
| Wood shake | 20 psf | Heavier than shingles, still within typical designs |
| Flat / low-slope (TPO, modified bitumen) | 15 psf | 20 psf minimum snow load applies — watch for ponding |
| Tile / slate | 25 psf | Often requires engineered framing — verify capacity |
If your result says Safe, your roof is within the typical 40 psf design capacity. Needs Review means the total exceeds 40 psf — have a professional inspect before the next heavy snow. Not Safe means the load is well above typical capacity and the roof should be evaluated immediately.
Roof Snow Load FAQ
The ground snow load (pg) for Tulsa, Oklahoma is 20 pounds per square foot (psf), per the International Building Code (IBC Figure 1608.2) and the ASCE 7 snow load maps. That means a roof in the Tulsa area is designed assuming snow on the ground can weigh up to 20 psf. For a typical sloped shingle roof, the code converts that ground load into a roof snow load of about 14 psf.
Most Tulsa-area homes are designed for a total roof load of 40 psf — about 20 psf of dead load (roofing materials and framing) plus 20 psf of live load (snow and temporary loads). With a 14 psf sloped-roof snow load, a typical asphalt shingle roof (15 psf dead load) lands around 29 psf total — comfortably within capacity. Concerns arise with heavy tile or slate roofs, flat roofs, older structures, or deep drifting snow.
Only if you see warning signs: sagging or creaking roof members, doors that start sticking, cracks in drywall near ceilings, or ice dams forming at the eaves. Never climb onto a snow-covered roof — use a roof rake from the ground on shallower pitches, or call a professional. Proof Construction offers snow-season roof inspections across the Tulsa metro; call (918) 734-4444.
Dead load is the permanent weight of the roof itself — shingles, underlayment, decking, and framing — plus anything permanently attached. Snow load is a live (temporary) load: the weight of accumulated snow and ice. Building codes add the two together and compare the total against the roof's design capacity, because the worst case is a fully loaded roof during a heavy Oklahoma winter storm.
If your calculation shows a total load above 40 psf — for example a tile roof, a flat roof with ponding, or an older home with undersized framing — have a licensed roofing contractor or structural engineer inspect it before the next heavy snow. Proof Construction offers free roof inspections for Tulsa-area homeowners: call (918) 734-4444 or request one online. If you see active leaking or sagging, that is an emergency — we provide 24/7 emergency tarping.