Deck Railings & Guards

The Building Code calls a deck railing a guard. Under the 2024 Ontario Building Code, a guard is required on each open side of a deck where the difference in elevation is more than 600 mm between the walking surface and the adjacent surface within 1.2 m. The test looks at the drop within 1.2 m of the edge, so a sloping yard can make a guard necessary where the deck edge itself looks low.

Height: Ontario sets 1 070 mm for guards generally, and allows 900 mm for exterior guards serving one dwelling unit where the walking surface is not more than 1 800 mm above the finished ground. Openings must stop a 100 mm sphere. Ontario goes further than the national code on climbing: every required guard must have no member, attachment or opening between 140 mm and 900 mm above the walking surface that will facilitate climbing. The national code limits that rule to guards more than 4.2 m up, so a guard design from outside Ontario may not meet it.

If the guard is a pre-engineered or manufactured system outside the Code's prescriptive rules, Ottawa asks for the manufacturer's information and attachment details with the permit. A deck that gives access to an above-ground pool falls under the Pool Enclosure By-law's gated-enclosure rules as well. Too few published Ottawa railing prices exist to quote a range.