How deep should deck footings be?

Deck footings must extend below the local frost line so they don't heave. The exact depth varies by region in BC — confirm with your building department.

How high does a deck railing need to be?

In BC, deck guards are generally 900 mm for lower decks and 1070 mm (about 42 inches) once the surface is more than 1.8 m above grade, with balusters spaced under 100 mm apart. Verify the current code.

How to Build a Deck: A Homeowner's Guide

A deck is one of the most popular DIY-friendly projects, but it's also structural — people stand on it, often well above the ground. Getting the footings, ledger, and railings right is what separates a deck that lasts decades from one that fails. Most decks above a low height need a permit, so start there.

Footings and posts

Deck loads transfer down through posts to footings that must reach below the frost line so they don't heave in winter. Frost depth varies across BC, so check your local requirement. Footings are sized for the load they carry and the soil they bear on.

The ledger connection

Where a deck attaches to the house, the ledger board is the most failure-prone part. It must be lag-bolted or through-bolted into the house framing — never just nailed — and flashed so water can't get behind it and rot the rim joist. Improper ledger attachment is a leading cause of deck collapses.

Framing the deck

Joists are sized and spaced for the span and decking material, tied to the ledger and beam with approved joist hangers. Use exterior-rated fasteners and hangers; ordinary ones corrode quickly outdoors. Pressure-treated, cedar, or composite are common decking choices.

Guards and stairs

Decks above a height threshold need a guard (railing). In BC the guard height is generally 900 mm for lower decks and 1070 mm (about 42 inches) once the walking surface is more than 1.8 m above grade, with baluster spacing tight enough that a 100 mm sphere can't pass. Stairs need consistent rise and run and a graspable handrail.

Get it inspected

If your deck needs a permit, inspections happen at set stages — often footings before pour and a final inspection. Don't skip them; they protect you and your insurance.