A Saskatoon truss drawing starts with two numbers stamped in the corner: 1.7 kPa of ground snow and 0.1 kPa of rain load sitting on top of it. That pairing, not the snow depth piled on your lawn, is what an engineer works from to size rafters and connections on a house in this province. Before you assume an existing roof is fine, or start pricing a re-roof, take the ground figure to your municipal building department or a licensed engineer and ask what it becomes for your specific roof geometry.
What is the ground snow load in Saskatchewan?
The ground snow load used for building design at Saskatoon is 1.7 kPa of snow (Ss) plus 0.1 kPa of associated rain load (Sr), listed under the reference city Saskatoon in the National Building Code of Canada 2020, Appendix C, Table C-2. That table runs down a list of localities across the country precisely because a province does not have one number. A roof near Prince Albert or in the far north sits under a different line of that same table, and a reader outside Saskatoon should look up their own nearest listed locality rather than borrow this one.
Ground load versus roof load
The figure above is a ground measurement, and it is not what a rafter actually carries. The NBC formula for the specified roof snow load is S = Is[Ss(Cb·Cw·Cs·Ca) + Sr]: the basic roof snow load factor (Cb) already discounts the ground value for an ordinary roof exposed the way most houses are, the wind exposure and slope factors (Cw and Cs) move it up or down depending on how sheltered and how steep the roof is, and the accumulation factor (Ca) can push it well above the ground figure wherever snow drifts. So the 1.7 kPa ground value is an input to a calculation, not the load stamped on a truss.
Who actually uses this number
This is the figure that shows up on a building permit application, in a plan reviewer’s file, and on the truss manufacturer’s engineering drawings before a single truss is cut. A homeowner rarely calculates the roof value themselves, but knowing where the 1.7 kPa and 0.1 kPa figures come from explains why a permit reviewer or engineer asks about roof slope, exposure and whether a lower roof sits next to a taller wall before signing off on anything. Alberta’s reference cities carry their own ground snow values under the same code, covered on our Alberta’s roof snow load and wind rules page, and they are not interchangeable with Saskatoon’s.
How much snow can a roof hold in Saskatchewan?
There is no single depth of snow a roof in this province “can take,” because the answer depends on the roof’s slope, its exposure, and what the snow itself has turned into. Before getting into that, it’s worth having the basics of roofing structure and terminology straight, since the terms below assume you know a rafter from a ridge.
Working from the ground figure
Starting from Saskatoon’s 1.7 kPa ground value, an ordinary heated, sloped house roof with typical exposure lands somewhere near seven-tenths of that ground figure once the basic factor is applied, before the rain load is added back in. That arithmetic is illustrative, not a design value you can use on your own roof: a steeper roof shed more efficiently and can land lower, while a shallow roof, a roof behind a parapet, or a lower roof section next to a taller wall can land considerably higher once the drift accumulation factor is applied. Drift is where roofs actually fail, far more often than the open, unobstructed field of a simple gable ever does.
Why depth alone tells you nothing
A foot of fresh January snow and a foot of wet March snow are not the same load. Cold, dry, fresh-fallen snow is light and fluffy. Once it settles, gets rained on, or partially melts and refreezes, the same depth packs far more water and far more weight into the same footprint, and a crust of ice on top adds more still. That is why a roof that carried a heavy early snowfall without complaint can struggle later in the season when a shallower but denser, wetter layer sits on top of what is already there.
Watch for the practical warning signs rather than trying to estimate load from a tape measure:
- Interior doors that suddenly stick or won’t latch
- New cracks in ceiling drywall, especially near load-bearing walls
- A visibly sagging ridge line or a roof surface that looks wavy from the ground
- Popping or cracking sounds from the attic framing
If you see any of that, the safe response is raking snow off from the ground with a roof rake, working from the eaves inward. Climbing onto a loaded roof is not the safe response, whatever the snow depth looks like from below.
What wind speed must a roof withstand in Saskatchewan?
The reference hourly wind pressure used for structural design at Saskatoon is 0.46 kPa, tied to a 1-in-50-year return period under the National Building Code of Canada 2020, Appendix C, Table C-2. This is a pressure, not a gust speed, and the Canadian code does not convert it to a wind speed for design purposes. Comparing it to a forecast’s mph figure or to a hurricane headline number is comparing two different kinds of quantity, and the comparison tells you nothing useful about either one. A second, lower figure, 0.36 kPa at a 1-in-10-year return period, exists for serviceability checks like cladding deflection and comfort, and it is never the number used to size structural connections.
What that 0.46 kPa pressure buys, on an actual roof, is the basis for shingle wind ratings, nailing patterns, sheathing fastening schedules, and the uplift connections tying the roof structure down to the wall framing below. Edges, rakes and ridges fail first in high wind, because that is where negative pressure, the suction that lifts material rather than pushes it, concentrates hardest. A fastening pattern that is adequate in the middle of a roof plane is routinely tightened up near those edges for exactly that reason.
Does Saskatchewan require an ice barrier under the shingles?
An ice barrier is a self-adhering waterproof membrane run along the eaves and up past the interior wall line, underneath the shingles. It does not stop snow from accumulating on the roof. Its entire job is to stop meltwater that backs up behind an ice dam from finding a seam in the shingles and reaching the wood deck underneath, where it can rot sheathing and soak insulation from above without anyone noticing until a ceiling stain shows up.
Why the risk is real here
Saskatoon’s mean daily minimum in the coldest month sits at about -20.7°C, according to Environment and Climate Change Canada’s 1981-2010 climate normals for that station. Combined with a ground snow load of 1.7 kPa sitting on roofs through a long winter, the conditions for ice damming, deep cold, a persistent snow cover, and periodic thaw-freeze cycles, are all present in an ordinary Saskatoon winter. Other parts of the province run colder or milder depending on latitude and elevation, but the mechanism does not change.
The code in force in Saskatchewan is the Building Code Regulations under The Construction Codes Act, derived from the 2020 edition of the National Building Code of Canada, administered by the Building and Technical Standards Branch within the Ministry of Government Relations and enforced locally, in force since January 1, 2024. The specific extension distance required for an eave membrane in this province is a detail your local building official applies at plan review, not a figure to guess at from a national model code. Ask your municipal building department directly rather than assuming a rule that applies somewhere else in the country applies here.
The membrane treats a symptom, not the cause. An ice dam forms because heat escaping from a warm attic melts the underside of the snowpack, that meltwater runs down to the cold overhang past the heated wall line, and refreezes there, building a ridge of ice that backs water up under the shingles above it. Air sealing the attic floor and bringing insulation up to the level appropriate for this climate zone stops the dam from forming in the first place. A membrane alone protects the deck from water that has already found a way in. It does nothing to stop the heat loss that caused the dam.
What roofing material suits Saskatchewan best?
The honest answer starts from the loads already on the table: a 1.7 kPa ground snow load, a 0.46 kPa design wind pressure at Saskatoon, and a climate zone, 7a at the Saskatoon Diefenbaker station under Natural Resources Canada’s heating degree-day classification, that calls for a well-sealed, well-insulated attic more than it calls for any particular shingle. Each common roofing category trades differently against those numbers.
| Material | Snow behavior | Weight added to structure | Wind consideration |
|---|---|---|---|
| Architectural asphalt shingles | Holds snow on the roof rather than shedding it | Light | Wind rating depends on the specific product and, just as much, on the nailing pattern used |
| Standing-seam metal | Sheds snow and ice in a sudden slide rather than holding it | Light | Panel and clip fastening at eaves and ridges carries most of the uplift resistance |
| Slate or concrete tile | Holds snow similarly to shingles | Heavy: the tile’s own dead weight adds directly to the snow load the structure must carry | Individual tile fixation matters more than the material itself |
A metal roof that sheds its snow load quickly is doing exactly what it is designed to do structurally, but that slide has to land somewhere. Positioning a standing-seam roof over an entry door, a walkway or a parked vehicle without a snow guard system is a design decision that needs to be made deliberately, not discovered the first time a roof unloads itself in a warm spell. Manitoba faces a comparable trade-off with its own local figures, detailed on our Manitoba’s roof snow load and wind rules page.
Where wind pressure governs the design, the fastening schedule and underlayment matter more than which material sits on top. A shingle rated for a high wind speed but nailed to a lower standard, wrong nail placement, too few fasteners per shingle, the wrong nailing zone near an edge, performs to the standard of the installation, not to the rating printed on the wrapper. None of this substitutes for a plan reviewed against the loads that actually apply to your address. That review belongs with your municipal building department or a licensed engineer, not with a general guide.