Rot Repair on the North Shore — Rotten Wood, Siding, Trim & Framing

Why wood rot is so common on the North Shore

We build and repair across the North Shore, and if there's one problem this climate creates more than any other, it's wood rot. North Vancouver and West Vancouver sit in a coastal rain forest: heavy rain, wind-driven rain that pushes moisture in behind siding and trim, long stretches of high humidity, and freeze-thaw through the winter that turns hairline gaps into open paths for water. Wood that gets wet and can't dry out will eventually rot — it's only a question of where and how far.

Rot is decay caused by fungus feeding on damp wood, so it always begins with a moisture problem. That's why the same spots fail again and again here: anywhere water collects, gets trapped, or slips past a failed seal. Keeping water out is the whole job of your building envelope, and when the envelope leaks, rot is what you find behind it.

Where rot shows up on a North Shore home

Rot rarely announces itself. By the time paint bubbles or a board feels soft, decay has usually been working out of sight for a while. On North Shore homes we find it most often in:

• Siding and exterior trim — fascia, corner boards, window and door casing, and the bottom courses of siding where water runs down and sits. This is where most rot starts; see our page on rotten siding and trim repair.
• Window and door sills — the horizontal ledges that catch and hold water when flashing or caulking fails.
• Decks, posts and stairs — post bases sitting on damp concrete and beam ends are classic failure points, covered in our guide to post and beam repair.
• Rim joists and wall framing — the structural wood behind the cladding, which rots when water gets past the siding and stays there.
• Subfloor — soft, spongy floors near exterior walls, bathrooms, or decks often mean the sheathing under your finished floor has gone.

The pattern is always the same: water finds a way in, the wood stays damp, and the rot spreads from there into whatever it touches.

Cosmetic rot vs. structural rot — the distinction that matters

The most important question with any rot is whether it has reached wood that holds your house up. That line is the difference between a straightforward repair and a structural one.

Cosmetic or surface rot lives in non-structural wood — a piece of trim, a fascia board, a section of siding. It still needs to be fixed properly, because the water getting in will keep spreading, but the wood itself isn't carrying load.

Structural rot is in the wood that carries weight: posts, beams, floor joists, rim joists, load-bearing wall studs, and sill plates. Once rot reaches these members it's no longer a paint-and-patch problem — it's weakening the frame of the building, and that is squarely structural repair work, which is our specialty. Rotten load-bearing wood is also one of the signs of a structural problem you shouldn't sit on.

From the outside these can look identical — a soft spot near a window could be one board of trim, or a rotted sill and framing hiding behind it. You don't know which until it's opened up, which is why an honest look matters more than a quick guess.

How we fix rot properly — not just paint over it

Rot that's painted over always comes back, because the water is still getting in. Fixing it properly means dealing with the cause, not just the symptom. Our approach is straightforward:

• Find and stop the water source first. Before we replace a single board, we track down how water is getting in — failed flashing, a gap in the cladding, worn caulking, a deck ledger, a roof or gutter issue. Skip this and the new wood rots too. It's the heart of water-ingress rot repair.
• Cut out all the affected wood. Rot spreads through wood the way a stain spreads through cloth, so we remove everything that's soft or compromised, not just the obvious part. Leaving punky wood in place lets the decay keep going.
• Treat and protect. We treat the sound wood at the edges of the repair and detail the rebuild to shed water and dry out — proper flashing, gaps, and sealing so it survives the next wet season.
• Rebuild it right. We replace what we removed with correctly sized material and, where it's structural, code-grade connections — restoring both the look and the strength.

Where the damage runs deeper into the exterior wall assembly, the work overlaps with building envelope renovation — fixing the wall system that's meant to keep water out in the first place.

Why rot in load-bearing wood is a structural job

When rot has reached load-bearing wood, replacing it safely means supporting the load, removing the failed member, and rebuilding the connection correctly — that's structural work, not general carpentry. Get it wrong and you either create a hazard or reproduce the same rot within a few years. We've been doing structural repair on the North Shore since 2008, now into our third generation, so we know exactly how this climate attacks wood and how to build repairs that last in it.

Not sure how far your rot has gone? Start with our free AI structural check for a fast read on whether what you're seeing is cosmetic or structural, or book a structural assessment and we'll tell you honestly what's failing and what it takes to fix. We serve homeowners across North Vancouver and West Vancouver — get in touch and we'll take a look.

Frequently asked questions

Can rotten wood be repaired, or does it all have to be replaced?

The rotten wood itself has to come out — rot is decay, and once wood has gone soft it doesn't recover, so we remove everything that's affected. What we save is the rest of your structure and the finish. The bigger point is that we also fix why it rotted; if the water source isn't stopped, any repair, no matter how good, will rot again.

How can I tell if my rot is cosmetic or structural?

The test is whether the rotten wood is carrying load. Trim, fascia, and siding are cosmetic — they still need fixing, but they don't hold the house up. Posts, beams, joists, load-bearing studs, and sill plates are structural, and rot in them is a structural repair. From the outside the two can look identical, so the honest answer is that it often takes opening up the area to know for sure.

Do you fix the leak, or just replace the rotten wood?

Both — and we find the leak first. Replacing rotten wood without stopping the water that caused it just resets the clock; the new wood rots too. So we track down how water is getting in — flashing, siding, caulking, a deck connection, gutters — stop it, and then rebuild. That's the difference between a repair that lasts and one that comes back.

What's the difference between dry rot and wet rot?

They're both fungal decay in damp wood; the names describe different fungi and how the wood looks and behaves. For your home it matters little which one it is — either way there's a moisture problem feeding it, the affected wood has to come out, and the source has to be stopped. We find the water, remove the decay, and rebuild so it doesn't return.

Do I need a structural engineer for rot repair?

For cosmetic rot in trim or siding, no. When rot has reached load-bearing framing, posts, beams, or sills, then yes — the repair should be designed and permitted, both for safety and for resale. We coordinate the engineering as part of the job so the fix is sized and detailed correctly rather than guessed at.