How Do I Remove Old Wallpaper from Plaster Walls in an Older Ottawa Home?

Removing wallpaper from plaster walls in an older Ottawa home is a project that requires patience, the right tools, and respect for what is underneath. Many Ottawa homes — especially in The Glebe, Sandy Hill, Old Ottawa South, Centretown, and Rockcliffe Park — have original horsehair or lime plaster walls dating back 80 to 130 years. Damaging that plaster during wallpaper removal can turn a cosmetic project into a structural repair job very quickly.

Assess What You Are Working With

Before you start stripping, identify two things:

What type of wallpaper is it?

• Vinyl or vinyl-coated: Has a slight sheen, feels almost plasticky. The vinyl top layer peels off in sheets, leaving a paper backing adhered to the wall. This is actually the easiest type to deal with.


• Traditional paper wallpaper: Fully paper-based, absorbs water readily. Common in Ottawa homes from the 1950s through 1980s.


• Painted-over wallpaper: This is the nightmare scenario, and it is extremely common in older Ottawa homes. Previous owners painted latex or oil paint directly over the wallpaper (sometimes multiple layers over multiple wallpaper layers). This is the hardest to remove and requires the most care.

What condition is the plaster in?
Press gently on the walls in several spots. If the plaster feels spongy, hollow, or moves when pressed, the plaster keys (the mechanical bond behind the lath) have broken. Aggressive wallpaper removal techniques can cause loose plaster sections to fall away entirely. Budget for plaster repairs if the walls feel anything less than rock solid — patches run $150 to $400 per area from an Ottawa plasterer.

The Step-by-Step Removal Process

Step 1: Protect the Room

• Lay heavy-duty canvas drop cloths on the floor (not plastic — it gets dangerously slippery when wet)
• Remove outlet covers and light switch plates
• Turn off power to the room at the breaker panel. Plaster walls in old Ottawa homes often have knob-and-tube or early Romex wiring, and you will be using water near electrical boxes. This is a genuine safety issue.
• Tape plastic over all outlets and switches even with power off

Step 2: Score the Surface

Use a wallpaper scoring tool (the Paper Tiger is the most common brand, about $10 to $15 at any Ottawa hardware store). Roll it across the entire wall surface to create tiny perforations in the wallpaper. This allows your removal solution to penetrate behind the paper.

Critical warning for plaster walls: Use light pressure only. The scoring tool has small spiked wheels that can gouge into soft lime plaster if you press too hard. You only need to puncture the wallpaper — not dig into the wall underneath.

Step 3: Apply Removal Solution

You have two effective options:

Commercial wallpaper remover (DIF is the most popular brand): Mix according to directions and apply with a pump sprayer or sponge. A bottle of concentrate costs about $10 to $15 and makes several gallons. Spray a section about 4 feet wide, let it soak for 10 to 15 minutes, then test a corner. If the paper slides off easily, you are ready. If not, apply more solution and wait.

Hot water and fabric softener: Mix one part liquid fabric softener to three parts hot water in a pump sprayer. This DIY method works surprisingly well and costs almost nothing. The surfactants in the fabric softener break down wallpaper adhesive effectively.

Avoid soaking plaster walls excessively. This is the key difference between plaster removal and drywall removal. Drywall can handle a fair amount of moisture; old plaster absorbs water and can soften, crumble, or delaminate from the lath. Apply removal solution in sections and work those sections before moving on. Never let solution sit on plaster for more than 20 minutes.

Step 4: Scrape Carefully

Use a 4-inch or 6-inch flexible putty knife — not a stiff scraper. Hold it at a low angle (about 30 degrees) to the wall and slide it under the wet wallpaper. The paper should come off in strips with moderate effort.

Do not use a rigid paint scraper or 5-in-1 tool — these gouge plaster instantly. The flexible putty knife bends against the wall surface and follows the contours of the plaster.

For painted-over wallpaper, you may need a wallpaper steamer. You can rent one from Ottawa tool rental shops for about $30 to $50 per day. Hold the steam plate against the wall for 20-30 seconds, then scrape while the paper is hot and soft. Steam is more effective than liquid on painted-over layers because the heat helps break down both the paint and the adhesive.

Step 5: Clean the Walls

Once all paper is removed, wash the walls with a sponge and warm water to remove residual adhesive. You will feel the adhesive as a sticky or tacky film when you run your hand over the surface. It must be completely removed before priming or painting — leftover adhesive causes paint to bubble and peel.

For stubborn adhesive residue, use trisodium phosphate (TSP) mixed with warm water. TSP is about $8 to $12 at Ottawa hardware stores. Wear gloves — it is mildly caustic.

Step 6: Repair and Prime

Inspect the plaster for:

• Cracks: Fill with setting-type joint compound (Durabond 90 is excellent for plaster). Do not use lightweight spackling — it shrinks and cracks over plaster.


• Gouges or dings: Build up with multiple thin layers of joint compound, sanding lightly between coats


• Loose sections: If plaster has separated from the lath, it needs professional repair. Plaster re-keying or replacement in Ottawa costs $200 to $500 per section depending on size.

Prime the repaired walls with a high-quality primer like Zinsser BIN (shellac-based) or Kilz Original. These block any remaining adhesive residue and provide a uniform surface for paint. A gallon runs $30 to $45 and covers about 300 square feet.

When to Hire a Professional in Ottawa

Consider hiring out the wallpaper removal if:

• There are multiple layers of wallpaper (very common in older Ottawa homes — we have seen homes with 4-5 layers dating back decades)


• The wallpaper has been painted over


• The plaster is in questionable condition


• The room is large or has high ceilings (Sandy Hill and Glebe homes often have 9-10 foot ceilings on the main floor)

Professional wallpaper removal in Ottawa costs $2 to $5 per square foot, depending on complexity. A typical 12x14 room with 9-foot ceilings has about 400 square feet of wall space, putting the cost at $800 to $2,000. This includes removal, wall repair, and priming.

Browse the Ottawa Construction Network directory to find contractors who handle wallpaper removal as part of their painting services. Ottawa Paint Contractors' Paint IQ is always available if you want to discuss your specific situation before starting.