What a Pressure Treated Deck Costs in Calgary

Millennium Fence and Deck · Updated October 2026 · 3 min read

A pressure treated deck costs $28 to $35 per square foot installed in Calgary. That's $4,032 to $5,040 for a 12 × 12, and $11,200 to $14,000 for a 20 × 20. It's the cheapest deck we build, and for a lot of yards it's the right answer.

What the price doesn't tell you is what the deck costs over the fifteen years you own it. That part matters more than the gap at quote stage.

Cost by size

Height, shape, stairs and railing move you within that range — a ground-level rectangle sits at the bottom, a raised multi-level deck with a long stair run at the top.

What pressure treated actually is

Softwood — usually spruce, pine or fir — with preservative forced into it under pressure. The chemicals are what stop it rotting; the wood itself has no natural resistance. That's the whole difference between it and cedar, and it's why it costs less.

It arrives wet. A newly built pressure treated deck holds a lot of moisture from the treatment process and won't take a finish properly until it's had a season to dry. Staining it too early is the most common mistake made on these decks.

The number that isn't on the quote

Pressure treated needs a clear sealer every one to two years, or a semi-transparent stain every two to three. Professionally that's $500 to $900 on a 400 sq ft deck. Do it yourself and it's about $150 in product plus a weekend.

Over fifteen years that's five to eight refinishes — $2,500 to $7,200 if someone else does it.

And the deck itself lasts 15 to 20 years here. Chinook freeze-thaw cycling — repeated expansion and contraction rather than one steady winter freeze — is what wears it out. After that you're not repairing, you're rebuilding.

So a 400 sq ft pressure treated deck that cost $11,200 to build costs roughly $13,700 to $18,400 over fifteen years once staining is counted, and then you build it again.

When it's still the right choice

We build these constantly and recommend them often. Pressure treated is the right call when:

• You're moving inside ten years. You won't be there for the rebuild. Build in pressure treated, spend the difference elsewhere, and the decision passes to the next owner.
• The deck is a surface, not a feature. A landing off a back door, a platform for a hot tub, somewhere the barbecue lives. Nobody's looking at it.
• The budget is genuinely fixed. A pressure treated deck you can pay for now beats a composite deck you finance.

When it isn't

If you're staying twenty years or more, the arithmetic turns over. Composite costs $42 to $58 a square foot to build and doesn't get rebuilt inside thirty years — which makes it cheaper to own even though it's dearer to buy. We've worked that through in composite deck cost in Calgary.

Keeping one alive longer

• Let it dry before the first finish. One season.
• Water test it. Pour a cup on the boards; if it soaks in inside thirty seconds instead of beading, the finish is spent.
• South-facing decks need refinishing a year sooner than shaded north-facing ones. We get a lot of clear days at this elevation and UV is what breaks a finish down.
• Keep the gaps clear. Debris packed between boards holds water against end grain, which is where rot starts.

Getting it built

See pressure treated decks in Calgary for how we build them, or how much a deck costs in Calgary for every material side by side.

We'll quote your yard in pressure treated and composite together so you can see the real gap rather than estimate it.