How much does it cost to remove old plaster walls and replace them with modern drywall in a Toronto Victorian home?

Removing plaster and lath walls and replacing them with modern drywall in a Toronto Victorian home is one of the most labour-intensive and expensive drywall projects you can undertake, typically costing $8.00 to $15.00 per square foot of wall surface — or $15,000 to $40,000 for a full home conversion in a typical two-storey Victorian. The high cost reflects the enormous amount of demolition labour, debris disposal, and the additional work required to bring old framing up to modern standards before new drywall can go on.

Plaster-and-lath construction is the standard in Toronto's established Victorian-era neighbourhoods — Cabbagetown, the Annex, Riverdale, High Park, Rosedale, Leslieville, Parkdale, and Roncesvalles are full of homes built between 1870 and 1930 with three-coat plaster over wooden lath strips nailed to the studs. Plaster walls are typically 3/4 to 1 inch thick, extremely heavy (a 4x8 section of three-coat plaster weighs 80 to 100 pounds compared to 50 to 60 pounds for drywall), and when you start pulling them apart, they shatter into heavy, dusty chunks that fill bins fast.

Demolition is the biggest single cost. Removing plaster and lath generates five to eight times more debris by weight than drywall demolition, and the dust is extraordinary — fine plite dust gets into every room, every surface, every crevice. Professional crews seal off work areas with poly sheeting and run negative air pressure, but plaster dust is relentless. Budget $3.00 to $5.00 per square foot for demolition alone, plus bin rentals ($400 to $800 each, and a full home will need three to five bins). A two-storey Victorian with 4,000 to 6,000 square feet of wall surface generates 15 to 25 tonnes of plaster debris.

Before demolition begins, asbestos testing is mandatory for any Toronto home built before 1990. While Victorian-era original plaster doesn't contain asbestos, many of these homes had repair work, joint compound, or textured coatings applied in the 1950s through 1980s that may contain asbestos. Testing costs $200 to $500 for multiple samples and is a small price compared to the health risks and legal consequences of disturbing asbestos-containing materials without proper abatement.

Once the plaster and lath are removed, the framing will need attention. Victorian-era studs are typically true-dimension lumber (a full 2 inches by 4 inches, not the modern 1.5 by 3.5 inches), spaced irregularly — sometimes 16 inches on centre, sometimes 18, sometimes whatever the original builders felt like. Studs may be bowed, twisted, or have notches cut for old gas lines and knob-and-tube wiring. Sistering warped studs, adding blocking, and shimming to create flat planes for the new drywall adds $1.00 to $3.00 per square foot. If the walls had knob-and-tube wiring (common in pre-1940 Toronto homes), an electrician will need to rewire before drywall goes up — this is a separate and significant cost.

Insulation is another consideration. Most Victorian homes in Toronto have little to no wall insulation. With the walls open, this is the ideal time to add insulation — batt insulation between studs with a 6-mil polyethylene vapour barrier is required by Ontario Building Code for any renovation that opens the wall cavity. Adding R-14 to R-20 insulation during the project adds $1.50 to $3.00 per square foot but dramatically improves the home's comfort and energy efficiency. Given Toronto's extreme winter temperatures (-10 to -20 degrees Celsius), this upgrade pays for itself within a few years in reduced heating costs.

Hanging and finishing new drywall on prepared walls costs $5.00 to $8.00 per square foot for a Level 4 finish, or $6.00 to $10.00 for Level 5. The irregular framing in Victorian homes makes hanging more challenging — sheets need more shimming and floating to achieve flat walls, and corner angles are rarely perfectly square. Plaster crown mouldings and ceiling medallions — if your Victorian home has decorative plaster features you want to preserve — need to be carefully protected or removed before demolition and reinstalled after drywall is up, adding custom carpentry costs.

An alternative to full removal is skim coating the existing plaster — applying a thin layer of joint compound over the plaster surface to smooth out cracks and imperfections while preserving the original walls. This costs $3.00 to $5.00 per square foot and works well when the plaster is structurally sound but cosmetically damaged. It preserves the character of the home and avoids the enormous cost and disruption of full demolition. However, if the plaster is crumbling, delaminating from the lath (hollow-sounding when tapped), or heavily water-damaged, skim coating is just putting lipstick on a problem.

This is exclusively professional territory requiring experienced crews who understand heritage home construction. Find contractors with specific experience in plaster-to-drywall conversion through the Toronto Construction Network directory at torontoconstructionnetwork.com/directory?trade=insulation.