How much does it cost to repair water damage behind tile in a Calgary shower wall?

Water damage behind a shower wall is not a tile repair — it's a structural remediation project, and in Calgary, costs typically run $2,000 to $8,000+ depending on how far the damage has spread and what's been affected behind the tile.

The honest answer is that the tile itself is often the least expensive part of this repair. What drives the cost is what the water found after it got through: rotted drywall or cement board, damaged wall framing (studs and blocking), mould remediation, and in some Calgary homes, insulated exterior walls where moisture has compromised the vapour barrier and insulation. Every layer has to come out, dry out, and be rebuilt correctly before a single tile goes back on the wall.

What You're Actually Paying For

The cost breakdown typically looks like this. Tile demolition runs $2–5 per square foot — shower tile is bonded hard and removal is slow, dusty work. Mould remediation, if present, adds $500–$2,500 depending on the extent; a professional mould assessment may be recommended before work begins, and in Alberta, significant mould in a living space is taken seriously by contractors and insurers alike. Framing repair or replacement varies widely — replacing a few rotted studs might be $300–$600 in labour and materials, but if a load-bearing wall or a corner has been compromised, you're looking at more. Substrate rebuild (cement board or foam backer, properly installed) runs $3–6 per square foot. Then comes the waterproofing membrane — Schluter Kerdi, Laticrete Hydro Ban, or RedGard — which is $300–$800 for a standard shower and is absolutely non-negotiable the second time around. And finally, new tile installation at $6–18 per square foot depending on tile type and complexity.

A standard 36-square-foot shower with moderate water damage — rotted cement board, some staining on the framing, no significant mould — typically runs $3,000–$5,500 all-in for demolition, remediation, substrate rebuild, waterproofing, and retiling. A larger shower, significant mould, or damaged exterior wall insulation can push that to $8,000–$12,000.

Why This Happens in Calgary Showers

The most common cause is a shower that was originally tiled without a proper continuous waterproof membrane — cement board alone, or worse, standard drywall with a skim of RedGard that wasn't applied to the corners and seams. Calgary's hard water accelerates grout deterioration, and once grout cracks or becomes porous, water migrates through the grout joints and into whatever substrate is behind. In Calgary's dry winters, the moisture behind the tile doesn't evaporate — it sits, and rot and mould follow.

The other common cause is failed silicone at the tub-to-tile or shower pan-to-wall joint. That flexible joint at the bottom of the shower wall is the most critical waterproofing point in the entire installation, and it's also the first thing to fail. Homeowners often re-caulk over old caulk rather than removing and replacing it, which creates a false seal that fails quickly.

What to Do Right Now

If you're seeing soft drywall, discoloured grout, tile that sounds hollow when tapped, or visible mould at the base of the shower wall, stop using the shower and get a contractor in to assess the extent of the damage before it spreads further into the wall cavity. The longer water sits in framing, the more expensive the repair becomes.

When the shower is rebuilt, insist on a full continuous waterproof membrane — not just cement board, not just a painted-on membrane at the corners. The membrane goes over the entire substrate, seams are taped with fabric mesh and membrane, and the pan-to-wall transition is fully sealed before a single tile goes up. Done correctly, a properly waterproofed Calgary shower should last 20–30 years without water intrusion.

Calgary Tiling can match you with a local tile contractor experienced in shower remediation and rebuild — get matched for free through the Calgary Construction Network at calgaryconstructionnetwork.com/directory?trade=tiling.