Drywall is not one-size-fits-all. Ontario Building Code and practical performance requirements mandate different drywall types in different locations — and using the wrong type leads to mould, failure, and expensive do-overs.
Standard Gypsum Board (Regular Drywall)
The baseline product. Used in: living rooms, bedrooms, hallways, ceilings in dry areas.
Thickness:
- 3/8" — legacy thickness, rarely used in new construction
- 1/2" — standard for walls and ceilings, 16" o.c. framing
- 5/8" — for 24" o.c. framing, fire-rated assemblies, and where added rigidity is needed
Not for: wet locations, garages (fire requirements), exterior-adjacent assemblies.
Moisture-Resistant Drywall (Green Board / Blue Board)
Gypsum core treated for moisture resistance. For: bathroom walls (not shower tile surfaces), basement walls in finished spaces, kitchens away from the sink.
Common misuse: Tile backer in showers. Moisture-resistant drywall is NOT a tile substrate for wet areas. Tile and grout are not waterproof — water reaches the substrate, and moisture-resistant drywall eventually fails.
For shower tile: use cement board (DenShield, Durock) or Kerdi Board (waterproof foam substrate). These are the Ontario standard for shower tile substrates.
Type X Fire-Rated Drywall
5/8" Type X provides a 1-hour fire rating (when used in code-compliant assemblies). Required for: garage-to-house demising walls (Ontario Building Code requires 1-hour fire separation), between units in multi-unit dwellings, mechanical room walls, and required fire-rated assemblies.
In Toronto, the most common application is the garage wall and ceiling adjacent to the living space — this must be 5/8" Type X, continuously and completely covered.
Soundproofing Drywall (Quiet Rock, SoundBreak XP)
Specialty panels with damping compound laminated within the board. Significantly reduces impact and airborne sound transmission. Cost: 4–8x standard drywall. Used in: home theatres, between bedroom walls in multi-unit, music rooms.
Exterior Ceiling Drywall (Purple / Exterior Drywall)
For covered exterior applications (soffits, carport ceilings). Standard gypsum board will fail in any moisture-exposed exterior location.
Drywall questions for your specific project at home.renovation.reviews.
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