Deck Stairs — OBC Requirements
Last updated: June 2026
Stair geometry, landings, guards, and handrails for deck access.
Detailed explanation
Deck stairs are subject to the same Part 9 stair provisions as other exterior stairs: rise, run, uniformity, width, handrails, and guards.
A landing is typically required at the top of exterior stairs where the door swings over the stair. The landing must be at least as wide as the door and provide standing space.
Stringers, tread support, and connection to the deck frame must be structurally adequate. Cut stringers have limits on notching depending on lumber size and span.
Ontario Building Code references
Ontario Building Code
Section 9.8.4. — Stairs
Stair construction requirements.
Ontario Building Code
Section 9.8.7. — Handrails
Handrail requirements on deck stairs.
Examples
- A deck with five steps from the sliding door needs a compliant landing at the door.
- Open-sided deck stairs require guards where the drop exceeds the code threshold.
Common mistakes
- Attaching stairs without a proper landing at the door threshold.
- Omitting handrails on short deck stair flights.
- Undersized stringers or footings at the bottom of deck stairs.
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