What is the cost to replace bathroom drywall with moisture-resistant board in Vancouver?

Replacing standard drywall with moisture-resistant board in a Vancouver bathroom typically costs $1,500 to $4,500 depending on bathroom size, the type of board used, and whether tile or other finishes need to be removed and reinstalled. This is one of the smartest upgrades you can make during any bathroom renovation in Metro Vancouver, where year-round humidity averaging 75-85% creates conditions that degrade standard drywall far faster than in drier Canadian climates.

First, an important distinction: moisture-resistant drywall (greenboard) and cement backer board serve different purposes. Greenboard is acceptable for bathroom walls and ceilings in areas that get occasional splashing but are not in direct wet zones — think the walls opposite the shower, the ceiling, and behind the toilet. Cement backer board (Durock, HardieBacker, or similar) is mandatory behind all tile in wet areas — shower walls, tub surrounds, and any wall receiving direct water contact. The BC Building Code does not permit standard drywall or even greenboard as a substrate for tile in shower and tub enclosures.

For a standard 5-foot by 8-foot bathroom, replacing all drywall involves removing the existing drywall (including any tile adhered to it), inspecting the framing and insulation behind for mould or moisture damage, installing the new board, and finishing. Here is what the costs look like:

Demolition and removal of existing drywall runs $500 to $1,500 depending on whether tile needs to come off first. If the bathroom has tile on the walls, removing the tile and underlying drywall together is standard practice — you cannot typically save tile during drywall replacement. Disposal fees in Metro Vancouver add $100 to $300 for a bathroom's worth of debris.

Moisture-resistant drywall (greenboard) costs $15 to $20 per 4-by-8-foot sheet compared to $12 to $15 for standard drywall. For a typical bathroom, you need 8 to 14 sheets depending on the room dimensions and ceiling height. Material cost: $120 to $280. However, the real cost is labour — hanging, taping, mudding, sanding, and priming drywall in a bathroom costs $800 to $2,000 for a standard-sized room.

Cement backer board for wet areas costs $25 to $40 per 3-by-5-foot sheet. For a standard shower enclosure (three walls at approximately 130 to 150 square feet), you need 8 to 10 sheets. Material cost: $200 to $400. Installation costs $600 to $1,500 because backer board requires special screws, proper spacing, and mesh tape with thin-set at the seams. Backer board is heavier and harder to cut than drywall, adding to labour time.

The hidden cost is what you find behind the walls. In Vancouver homes, particularly those built before 2000 where standard drywall was used in bathrooms, removing the old drywall frequently reveals mould growth in the wall cavity — especially on walls adjacent to showers or tubs where moisture has been wicking through for years. Mould remediation adds $500 to $3,000 depending on the extent of growth. You may also discover deteriorated insulation (common in exterior bathroom walls in older Vancouver homes), inadequate vapour barrier, or framing damage that needs repair.

If the bathroom is already stripped to studs as part of a larger renovation, the incremental cost of using moisture-resistant drywall and cement backer board instead of standard drywall is modest — typically $300 to $800 more in materials and labour. This is why bathroom renovation professionals in Metro Vancouver always recommend doing this upgrade during any gut renovation rather than as a standalone project.

For a standalone drywall replacement in a bathroom that is not being otherwise renovated, expect these total ranges: A small powder room or half bath with no wet areas runs $1,500 to $2,500 (greenboard throughout). A standard full bathroom with shower or tub runs $2,500 to $4,500 (cement backer board in wet areas, greenboard elsewhere, including tile removal and reinstallation in the shower area). A larger master ensuite can reach $4,000 to $6,000+.

Once the new moisture-resistant board is installed, paint all non-tiled surfaces with a quality mould-resistant semi-gloss or satin paint. Ensure the bathroom has an exhaust fan rated at 50-80 CFM minimum, ducted to the exterior — the best moisture-resistant drywall in the world will still develop mould if the bathroom lacks adequate ventilation in Vancouver's climate.