Deck Stairs

Deck stairs follow the private-stair limits in Ontario's amended Building Code. Exterior stairs serving a single dwelling unit may have a rise of 125 mm to 200 mm and a run of 255 mm to 355 mm, and each rectangular tread must be no shallower than its run and no deeper than the run plus 25 mm.

Handrails: exterior stairs serving a single dwelling unit need no handrail with 3 risers or fewer. With more than 3 risers, one handrail is enough on exterior stairs serving one dwelling unit. Ontario sets required handrails at 865 mm to 1 070 mm high, with 50 mm of clearance behind them (60 mm if the surface behind is rough). Guards still apply to the sides of a stair where the drop is more than 600 mm within 1.2 m; on a stair, guard height is measured from a line through the tread nosings, and the triangle under the bottom rail must stop a 150 mm sphere.

Ottawa's permit drawings ask for stair construction and location on the framing plan and the rise and run on the elevation. Too few published Ottawa stair prices exist to quote a range, and the two we found use different units.