When to Replace Your Deck — and When to Repair It

Millennium Fence and Deck · Updated October 2026 · 4 min read

Most decks in Calgary last 15 to 20 years. Replace it when the structure has gone — soft posts, movement underfoot, rot at the ledger — and repair it when only the surface has. A deck with sound framing and tired boards is a re-deck, not a rebuild, and it costs meaningfully less because the substructure and footings stay.

Here's how to tell which one you're looking at.

Replace it if any of these are true

1. The posts are soft at the base. Push a screwdriver into the post where it meets the footing. If it goes in, the post is gone. This is the one that ends the conversation — everything above a failed post is unsupported.

2. It moves when you walk on it. Some bounce between joists is normal. Lateral sway is not. A deck that shifts side to side has lost its bracing or its connections, and that's a structural failure, not a maintenance item.

3. The ledger is rotten or pulling away. The ledger is the board attaching the deck to the house, and it's the most common point of catastrophic deck failure anywhere. Staining or soft wood where the deck meets the wall means water has been getting behind it, possibly for years.

4. Footings have heaved. Look along the deck edge. If it's no longer level and one corner has lifted, the footings didn't reach frost depth and our freeze-thaw cycles have moved them. You can't fix that from the top.

5. More than about a third of the boards need replacing. Below that, replace boards. Above it, you're paying most of a new deck's material cost to keep an aging substructure.

6. It doesn't meet current code and you're changing it anyway. Guard heights and spacing have changed over the years. If you're touching it substantially, bringing it to current standard is usually cheaper as part of a rebuild than as a retrofit.

7. It's over twenty years old and it's wood. Not decisive on its own, but worth an honest look at the other six.

Repair it if

• The framing is sound and it's only the surface boards that have weathered
• There's localised rot — a few boards, one stair tread
• Railing is loose but posts and framing are solid
• It's structurally fine and you want it to look different — a re-deck over existing framing is a real option and much cheaper than a rebuild

A re-deck keeps the substructure and replaces the walking surface and railing. If the framing has another decade in it, that's the best value available on an aging deck — and it's the route to a composite surface without paying for a full composite build.

What replacement costs

Same rates as a new build, because it largely is one:

Two things add to a replacement that a new build doesn't carry:

Demolition and disposal. Tearing out and hauling away the old deck. Modest, but real.

Whatever's underneath. Old footings sometimes have to come out, and what's found when the deck comes off occasionally changes the plan — a ledger that's been leaking usually means siding and sheathing repair before anything new goes on.

Full costs by deck size are in how much a deck costs in Calgary.

Do you need a permit to replace a deck?

Usually yes. A building permit is required for any deck with a roof or pergola, and for any uncovered deck higher than 0.6 m (2 ft) above grade at any point — and that applies to rebuilding an existing one, not just building new. Replacing a raised deck is a permitted job.

A straight re-deck over sound existing framing, at the same height and footprint, is a different question — our permit guide covers what triggers what.

The mistake worth avoiding

Spending real money on a deck whose posts are going.

We see decks that have had two rounds of board replacement and a new railing sitting on a substructure at the end of its life. That money would have been most of a rebuild, and the rebuild would have come with another twenty years.

If the framing is sound, maintain it — it's worth maintaining. If it isn't, spend the money once.

Getting it looked at

We'll tell you which one you've got. If the framing is sound and it's only the surface that's gone, we'll say so rather than quote you a rebuild — there's no version of this where selling someone a deck they don't need works out for us.

See deck installation in Calgary for how we build.