How much does moisture-resistant drywall cost compared to regular drywall at Toronto-area suppliers?

Moisture-resistant drywall costs roughly 40–60% more than regular drywall at Toronto-area suppliers, with the price gap widening further if you step up to mould-resistant board. Standard 1/2-inch regular drywall runs $14–$20 per 4x8 sheet in the GTA, while moisture-resistant green board (same 1/2-inch thickness) costs $20–$28 per sheet, and premium mould-resistant purple board with fibreglass facing runs $24–$32 per sheet.

The price difference is significant when you are boarding an entire basement bathroom or a large kitchen, but it is a fraction of the cost of tearing out mould-contaminated regular drywall two or three years down the road. In Toronto's climate — where humid summers push indoor humidity levels well above 60% and basements are naturally damp — using the right board in wet and high-moisture areas is not a luxury, it is basic moisture management.

Green board versus purple board — what is the actual difference? Green board (moisture-resistant drywall) has a water-resistant paper facing and a moisture-resistant gypsum core. It handles the elevated humidity found in bathrooms, kitchens, and laundry rooms better than regular drywall, but it is not waterproof. It should never be used as a tile substrate in showers or tub surrounds — that requires cement board (Durock or HardieBacker, $25–$40 per 3x5 sheet). Purple board (mould-resistant drywall like CGC's M2Tech or GP's DensArmor Plus) goes further by replacing the paper facing entirely with fibreglass mat. Since mould feeds on paper, removing the paper eliminates the primary food source. This makes purple board the better choice for chronically damp areas like below-grade basement bathrooms, laundry rooms adjacent to exterior walls, and any room where ventilation is limited.

For a practical GTA comparison, consider a typical basement bathroom renovation (roughly 200 square feet of wall area). Using regular drywall would cost about $90–$125 in board alone. Green board bumps that to $125–$175, and purple board to $150–$200. The material difference is only $35–$75, which is trivial compared to the total project cost of $5,000–$12,000 for a basement bathroom renovation. Given that basement moisture problems are the single most common drywall complaint in GTA homes — especially in the post-war housing stock across Scarborough, North York, and the inner suburbs — spending the extra $50–$75 on mould-resistant board is the most cost-effective insurance you can buy.

Where to Use Each Type

Regular drywall is perfectly fine for bedrooms, living rooms, dining rooms, hallways, and any dry interior space. Green board is appropriate for kitchen walls and ceilings, powder rooms with low moisture exposure, and laundry rooms with good ventilation. Purple board or DensArmor Plus is the right choice for full bathrooms (walls and ceilings not in direct water contact), basement rooms in older GTA homes with any history of dampness, and any space where ventilation is limited or humidity runs high.

One critical point that many homeowners miss: moisture-resistant drywall protects the board itself from moisture damage, but it does not prevent moisture from entering the wall cavity. In basement applications, you still need a properly installed 6-mil polyethylene vapour barrier on the warm side of the insulation, as required by the Ontario Building Code for Climate Zone 6. Without the vapour barrier, warm moist air from inside the room will condense on the cold foundation wall behind the drywall, and no amount of moisture-resistant board will prevent mould growth inside the wall cavity.

Most GTA building supply stores — Home Depot, Rona, Home Hardware, and specialty drywall suppliers — carry all three types in stock. For larger orders (10+ sheets), delivery is typically $50–$150 depending on location, with many suppliers offering free delivery on orders over $500. If you are planning a bathroom or basement project and want professional guidance on material selection, Toronto Drywall Installers can match you with a local drywall contractor for a free estimate.