BC deck railing rules, explained plainly

A deck railing in BC has one job: to keep someone from going over the edge. That is why the code sets a height, limits the gaps, and asks for safety glass. On most decks the guard is 36in tall; once the deck sits well above the ground, it steps up to 42in. Here is how the rules work.

When does a deck actually need a railing?

Not every deck needs a guard. The deciding factor is how far you could fall. Once the walking surface is more than about 2ft (24in) above the ground beside it, BC code requires a guard along the open edges. Below that — a step or two off the lawn — you can leave the edge open. It is worth measuring before you assume anything. A deck that looks low where it meets the house can be well over 2ft at the far corner, where the yard slopes away, and that corner is exactly where a guard has to be.

How tall does a deck railing have to be?

There are two heights, and the drop below the deck decides which one applies. Up to about 6ft above the ground, the guard has to be at least 36in tall. Once the deck is more than about 6ft up, the guard steps up to 42in. The reason is straightforward: the higher the deck, the worse a fall, so the code asks for a taller barrier you cannot easily tip over. On a two-storey deck or a balcony, plan on the taller 42in guard. We confirm the height your deck needs when we measure the site, because a single deck can cross the 6ft line partway along its length as the ground drops beneath it.

How wide can the gaps between pickets be?

This is the rule people miss. The vertical gaps between pickets have to be narrow enough that a 4in sphere cannot pass through them. The number is not about the railing looking tidy — it is sized so a small child cannot fit through the opening or get their head caught in it. The same limit applies near the bottom rail and around any decorative pattern in the guard. When we build an aluminum picket railing, the pickets are spaced to hold that 4in limit along the whole run, corners included, so there is no wide gap where two sections meet.

What are the rules for glass railings?

A glass guard has to do everything a picket guard does — the same heights, the same job — and the glass itself has to be safety glass. For a framed railing that means tempered glass: heat-treated so that if it ever breaks, it crumbles into small blunt pieces instead of long shards. Some designs call for laminated glass instead. Either way, ordinary window glass is never allowed in a guard.

We install a framed glass system, where each tempered panel sits captured in a powder-coated aluminum frame with a top rail that carries the load. We do not market a frameless system, where the glass itself is structural — that path drives the engineering and the cost up sharply, and a framed panel can be swapped out later without rebuilding the run. If the view is the reason you built the deck, framed glass keeps it while meeting the same height and safety rules as any other guard. There is more on our glass railing page.

How strong does a deck railing have to be?

Height and spacing are only part of it. A guard also has to be strong enough to stop a person who trips, leans, or falls against it — a barrier that meets the height but flexes or pulls loose is not doing its job. The code sets a force the guard has to withstand at the top rail without failing, and that requirement is the real reason the posts, their spacing, and how they anchor to the deck matter as much as the height number. This is where a lot of older or homebuilt railings fall short: they look tall enough, but the posts are under-anchored and give when pushed. On our systems the powder-coated aluminum frame carries that load, and the posts are fastened to hold it along the whole run. It is also why a guard is more than pickets and a rail — the structure behind them is what actually keeps someone on the deck.

Do balconies and higher decks follow different rules?

The principles are the same; the numbers just land at the top of the range. A balcony is a raised deck, so it is almost always tall enough to need the 42in guard, and it always needs a guard of some kind. The picket-gap and safety-glass rules do not change with height — a 4in sphere is a 4in sphere whether the deck is 3ft or 30ft up. What changes on taller and multi-storey structures is how carefully the connection to the building and the anchoring of the posts are detailed, because there is more load and more consequence if any of it is wrong.

Who checks that a railing meets code?

Your municipal building department, through the permit and inspection process. When a railing is part of a permitted deck, an inspector confirms the height, the picket spacing, and how the guard is attached before the job is signed off. If you are replacing a guard on an existing deck, some municipalities treat that as permit work on its own — we cover which ones in our guide to deck permits across Greater Victoria. Building to these rules from the start is far cheaper than being asked to redo a finished railing that came up short at inspection.

Can you keep an older railing that no longer meets the rules?

Heights and spacing have tightened over the years, so plenty of older decks on the Island carry guards that would not be built the same way today — a rail that sits a little low, or pickets spaced wider than a 4in sphere allows. An existing railing built to the rules of its day can usually stay as it is while it remains untouched. The moment you rebuild or replace it, though, the new guard has to meet today's heights and spacing, not the old ones. Your building department has the final say on what counts as a repair versus a replacement, which is worth confirming before you start — a project you think of as a refresh can land on the replacement side of the line and pull in the current code.

What does this mean for your deck?

In plain terms: measure the drop, and let it tell you the height. If the deck is more than about 2ft above the ground, it needs a guard. Up to about 6ft, that guard is 36in; above 6ft, it is 42in. Whatever fills it — pickets or glass — has to close the gaps to a 4in sphere and use safety glass where it is glass. Everything else, from post spacing to how the railing anchors, follows from those few numbers.

None of this has to be complicated from your side. Tell us about your deck — how high it sits, whether you want pickets or glass, and where the view is — and we handle the heights, the spacing, and the safety glass so the guard passes inspection the first time. If you are in Victoria, Oak Bay, or anywhere on the south Island, request an estimate and we will confirm exactly what your deck needs.