Handrail clearance from a rough brick wall on Ottawa deck stairs?

Leave 60 mm: the 2024 Ontario Building Code sets that clearance between the back of the handrail and a rough or abrasive surface, under section 9.8.7.5(1). If the wall behind the handrail is smooth, the minimum drops to 50 mm.

If the brick behind the handrail is rough or abrasive, the 60 mm figure is the one to design to.

A few things shape how this plays out on your stair run. Required handrails are 865 mm to 1 070 mm high, under section 9.8.7.4(2). On exterior stairs serving a single dwelling unit, a handrail is only required where there are more than three risers, under section 9.8.7.1. If your stair has three risers or fewer, the Code does not require one at all, though you may still choose to install one.

Put the handrail height and its clearance on the drawings rather than leaving them to the installation day.

If the stair is part of a deck that sits more than 600 mm (24 in.) above the adjacent grade and is attached to or next to the house, a building permit is required under the City of Ottawa's rules. The permit drawings must show stair construction and location, rise and run, and guard and handrail information. The City's framing and final inspections are booked 48 hours in advance.

If you have not yet confirmed whether your project needs a permit, that is the right place to start: contact the City of Ottawa's Building Code Services with your deck height and whether the stair is attached to the house.