What drywall accessories and supplies should I buy before starting a basement finishing project in the GTA?

Before starting a basement finishing project in the GTA, you need a comprehensive materials list that goes well beyond just drywall sheets — the accessories and supplies are what determine whether your finished basement walls and ceilings look professional or amateur. A typical 800–1,200 square foot basement finish will require a substantial materials investment, and having everything on hand before the crew starts (or before you start, if you are tackling portions yourself) prevents costly delays and mid-project supply runs across Toronto traffic.

Here is what you need, organized by stage of the drywall scope:

Boarding and Framing Supplies

Drywall boards are the obvious starting point. For basement walls, use 1/2-inch moisture-resistant (green board) or mould-resistant (purple board) at $20–$32 per 4x8 sheet — regular drywall is a risky choice in GTA basements given our humid summers and the inherent dampness of below-grade spaces. For the basement ceiling, 1/2-inch regular or lightweight drywall is typically fine at $14–$24 per sheet, unless you have a furnace room that requires 5/8-inch Type X fire-rated board at $20–$28 per sheet. Calculate your square footage, divide by 32 (the area of a 4x8 sheet), and add 10–15% for waste from cuts around windows, doors, electrical boxes, plumbing, HVAC runs, and columns.

You will also need a 6-mil polyethylene vapour barrier — this is code-required in Ontario for basement walls and goes between the insulation and the drywall on the warm side. Budget $50–$80 for a 10x100-foot roll, plus acoustic sealant ($8–$12 per tube) to seal the poly at all seams, penetrations, and perimeter edges. Tuck tape ($8–$15 per roll) seals poly seams. Without a properly sealed vapour barrier, moisture will condense inside your wall cavities and you will have mould within two to three years — this is the single most common basement finishing mistake in the GTA.

Drywall screws: Use 1-1/4-inch coarse-thread screws for 1/2-inch board and 1-5/8-inch for 5/8-inch board. Buy screws by the box — a 1,000-count box runs $25–$40 and covers roughly 30–40 sheets at proper spacing (every 16 inches on walls, every 12 inches on ceilings). You will also need a drywall screw gun or an impact driver with a dimple bit adapter ($15–$25) to set screws to the correct depth without breaking the paper face.

Taping, Finishing, and Accessories

Joint compound: For an 800 square foot basement, plan on 3–4 boxes of pre-mixed all-purpose compound (17L each, $18–$25 per box) for the bedding and second coats, plus 1–2 boxes of topping compound ($20–$28 each) for the final finish coat. If you are working in winter in a basement that is not yet fully heated, pick up a bag of setting compound (hot mud) in 90-minute set time ($15–$22) — it cures by chemical reaction rather than air drying, so it works reliably in cold conditions where pre-mixed compound will not cure properly.

Tape: Buy at least 3–4 rolls of paper tape ($5–$8 per 75-metre roll) — paper tape is stronger than mesh for flat joints and inside corners, which are abundant in basements. For corner protection, you need metal or vinyl corner bead ($3–$8 per 8-foot piece) for every outside corner, plus paper-faced inside corner bead for cleaner inside corners if you want a professional result.

Sanding supplies: A pole sander ($25–$40) with 120-grit and 150-grit sanding screens or sandpaper is essential for finishing. A sanding sponge ($5–$8) handles detail work around corners and edges. A bright work light ($30–$60) positioned at a raking angle is critical for spotting imperfections during sanding — overhead lighting hides flaws that will be glaringly visible once the room is furnished.

Finally, do not forget PVA drywall primer ($30–$50 per 3.78L can) — this seals raw drywall and compound evenly so paint covers uniformly without flashing. Skipping primer is the most visible shortcut in drywall finishing, and it shows up as visible joint lines under every lighting condition.

For a complete basement drywall scope in the GTA, expect to spend $2,500–$5,000 on materials alone for an 800–1,200 square foot space. A professional drywall crew will typically quote $5,000–$12,000 for the full drywall scope including materials, labour, and finishing. Toronto Drywall Installers can match you with experienced basement finishing contractors in your area for free estimates.