Snow Load and Roof Design

In much of Canada, the roof is where winter is won or lost. It has two jobs at once: keep the heat in and carry — or shed — a serious weight of snow. Getting the roof form and structure right is as important as the insulation beneath it.

Snow load is a real, regional number

Snow load is the weight of accumulated snow and ice a roof must carry. It varies widely by region and is set by local building requirements, and it is not trivial: wet spring snow is far heavier than fresh powder, and drifting can pile it unevenly. A roof that shrugs off a light winter can fail under a heavy one if it was never designed for the load. This is a matter for your local requirements and a qualified professional — the archive flags it, it does not set the figure.

The roof forms, compared

• Gable — the classic two-slope roof. Sheds snow readily from both sides and adds ceiling volume. The archive’s default for cabins and traditional forms.
• Shed / single-pitch — one slope. Simple and economical, sheds to the low side; gives a lower ceiling on that side. Common on sheds and compact cabins.
• Mono-pitch — a pronounced single slope, often steeper, for a modern look that still sheds snow. Used on several modern profiles.
• Flat (warm flat roof) — a low-slope membrane roof over tapered insulation. Carries snow rather than shedding it, so it must be engineered for the load with proper drainage. Advanced, and central to the archive’s cube and modern profiles.

Shedding vs carrying

There are two valid strategies. A steeper pitched roof sheds snow, keeping the load low but dropping it somewhere — plan where, so it does not block the door or pile against the wall. A flat or low-slope roof carries the snow, which demands a stronger structure and reliable drainage but keeps the silhouette clean. Neither is wrong; they are different engineering choices.

Overhangs earn their keep

Generous overhangs push shed snow and meltwater clear of the walls, door and foundation. In a wet, freeze-thaw climate this protection matters as much as the roof covering itself, keeping water away from the parts that rot.

Roof form and the heater

Roof choice is not only structural. A gable adds ceiling volume — more air to heat, nudging the heater class up. A flat or low roof keeps volume tight and efficient. This is one more reason the archive lists roof type alongside heater class: they are related decisions.

Reading it in the catalogue

Each profile states its roof type, and its climate tags show whether it is drawn for high snow load. Pair those with the insulation guide: a cold-climate sauna is a whole assembly — envelope, roof and foundation working together against the winter.