AntoineAsphalt.caDeck railing guide
Deck Railing Requirements in Ontario (Guard Height & Rules)
Under the Ontario Building Code, a deck needs a guard once the walking surface is more than 600 mm above adjacent grade. The guard must be at least 900 mm high where the deck is not more than 1.8 m above grade, and at least 1,070 mm above that, with openings that will not pass a 100 mm sphere. Confirm current requirements with your municipality before building.
Under the Ontario Building Code, a deck needs a guard once the walking surface is more than 600 mm above adjacent grade. The guard must be at least 900 mm high where the deck is not more than 1.8 m above grade, and at least 1,070 mm above that, with openings that will not pass a 100 mm sphere. Confirm current requirements with your municipality before building.
When does a deck need a railing in Ontario?
A guard is required where the walking surface is more than 600 mm above adjacent grade. Many homeowners add a railing to lower decks too for comfort, but it is the 600 mm trigger that makes it a code requirement.
How high does a deck railing need to be?
Guard height depends on how far the deck is above grade.
| Deck height above grade | Guard required? | Minimum guard height |
|---|---|---|
| 600 mm or less | Not by this trigger | — |
| More than 600 mm, up to 1.8 m | Yes | 900 mm |
| More than 1.8 m | Yes | 1,070 mm |
Confirm current requirements with your municipality before building.
How far apart can railing pickets be?
Guard openings must not allow a 100 mm sphere to pass through. That applies to gaps between pickets, under the bottom rail and around glass panels. Designs with horizontal members can raise climbability concerns for children; confirm with your municipality whether a horizontal design is acceptable for your deck height before ordering.
What about stair railings and handrails?
Stairs must meet Ontario Building Code rise, run, guard and handrail rules. We design stairs to the current code and the permit drawings for each project rather than relying on rules of thumb, because requirements vary with stair width and height.
Do I need a permit to replace my deck railing?
In Hamilton, yes — replacing existing guards or installing new guards requires a permit. This also applies in Ancaster, Dundas, Stoney Creek, Waterdown and Flamborough. In Burlington and Oakville, confirm with the municipality before replacing a guard.
Which deck railing type should I choose?
Railing is one of the most visible parts of a deck, and prices vary widely.
| Railing | Typical range | Best for |
|---|---|---|
| Aluminum picket | About $80–$150 / linear ft | Clean, low-maintenance; black is most requested |
| Aluminum + glass | About $150–$400 / linear ft | Keeping views open over yards and ravines |
| Horizontal cable or bar | Quoted on site | Modern look — confirm climbability acceptance |
| Composite or wood | Quoted on site | Matching the deck boards; wood needs staining |
Typical Ontario installed ranges (2026). Your exact price comes from an on-site quote.
What should I know about glass railings?
Glass keeps sightlines open but shows water spots and pollen, so it needs occasional cleaning. Panels must still meet guard height and loading requirements, and bottom gaps must stay under the 100 mm sphere limit. On windy, exposed lots, framed glass with a top rail is a practical choice.
Can railing lighting be added?
Yes. Post-cap lights, under-rail strips and stair lights make a deck safer and more usable in the evening. Lighting is easiest when the wiring sleeves are planned before the boards and railing go on.
Can I upgrade the railing on my existing deck?
Often, yes, if the posts, rim joists and blocking are sound enough to anchor a new guard. We check the framing first, since a new railing is only as strong as what it is fastened to. In Hamilton, the guard replacement needs a permit.
Frequently asked questions
At what height does a deck need a railing in Ontario?
When the walking surface is more than 600 mm above adjacent grade.
Is 36 inches high enough for a deck railing?
The Ontario minimum is 900 mm (about 35.4 in) for decks up to 1.8 m above grade and 1,070 mm (about 42 in) for higher decks. Confirm current requirements with your municipality before building.
How much space is allowed between railing spindles?
Openings must not let a 100 mm sphere pass through.
Do I need a permit to replace deck railings in Hamilton?
Yes. The City of Hamilton requires a permit for new or replacement guards.
How much does aluminum deck railing cost?
Typical Ontario installed ranges (2026) are about $80–$150 per linear ft for aluminum picket and $150–$400 for aluminum with glass. Your exact price comes from an on-site quote.
Are horizontal deck railings allowed?
Horizontal designs can raise climbability concerns. Confirm with your municipality whether the design is acceptable for your deck height before ordering.
Related deck information
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Get an on-site deck quote
Call (647) 459-7775 or send the essentials. Your exact price comes from an on-site quote.