Can I wallpaper over existing wallpaper in my Ottawa home or must I strip it first?

The short answer is: you should almost always strip the old wallpaper first. I know that's not what you want to hear — stripping wallpaper is tedious, messy work — but layering new wallpaper over old almost always creates problems, and Ottawa's climate makes those problems worse. Let me explain why, and cover the rare exceptions.

Why Stripping First Is the Right Call

Adhesion issues are the primary concern. New wallpaper adhesive bonds to whatever surface it contacts. When that surface is old wallpaper rather than a properly primed wall, you're relying on the old adhesive (which may be 10-30 years old and degraded) to hold both layers. If the old paper lets go, both layers come down together.

Ottawa's extreme humidity swings magnify this risk. Our indoor humidity drops to 20-30% in winter when furnaces run constantly, then climbs to 60-80% in summer. This seasonal moisture cycling causes wallpaper to expand and contract. Two layers of wallpaper respond to moisture at different rates, which creates bubbling, wrinkling, and delamination between the layers. What looks fine in October can be a wrinkled mess by February.

Additional reasons to strip first:

• Old wallpaper patterns and textures telegraph through the new layer, creating visible bumps and shadows — especially with lighter-coloured or thinner wallpapers


• Seams from the old wallpaper create ridges that show through the new installation


• Any existing mould, mildew, or moisture damage behind the old paper gets sealed in rather than addressed — a genuine health concern


• Future removal becomes exponentially harder with multiple layers (your next project becomes a nightmare)

The Rare Exceptions

There are a few narrow situations where wallpapering over existing paper can work:

Single layer of smooth, vinyl-coated wallpaper that is:

• Firmly bonded with no lifting, bubbling, or peeling anywhere


• Completely smooth with no textured pattern


• Clean and free of grease, smoke residue, or staining


• On a flat, stable wall (not plaster with underlying cracks)

Even then, you'd need to score the old vinyl surface with a scoring tool so the new adhesive can grip, then apply a bonding primer before hanging new paper. And you accept the risk that Ottawa's seasonal extremes may still cause issues down the road.

Lining paper over old wallpaper is another option professionals sometimes use. A heavy-duty lining paper (1000-1200 grade) applied horizontally can bridge minor imperfections and create a fresh bonding surface. This adds $1.50 to $3.00 per square foot to your project but is still faster than full stripping in some cases.

The Stripping Process for Ottawa Homes

The approach depends on your wall type and existing wallpaper:

For drywall (post-1960s homes, common in Kanata, Barrhaven, Orleans, Riverside South):

• Score the wallpaper surface with a Paper Tiger scoring tool ($10-$15)


• Apply wallpaper remover solution or a fabric softener and hot water mix


• Let it soak for 15-20 minutes


• Scrape with a wide putty knife — the paper should come off in sheets


• Wash residual adhesive with TSP solution


• Repair any drywall damage, prime with wallpaper-specific primer


• Total DIY cost: $50 to $100 in supplies for a single room

For plaster walls (pre-1960s homes, common in the Glebe, Centretown, Sandy Hill, Old Ottawa South, New Edinburgh):

• Extra caution required — plaster is more fragile than drywall and can crack or gouge


• Use a steamer ($30-$50/day rental from an Ottawa tool rental shop, or $80-$150 to buy)


• Work in small sections, holding the steamer pad for 30-60 seconds before scraping


• Never use a metal scraper aggressively on plaster — use a plastic scraper to avoid gouging


• Budget extra time for skim coating damaged areas before re-papering


• Professional stripping recommended for plaster walls: $2 to $5 per square foot

For multiple layers of old wallpaper (common in older Ottawa heritage homes):

• This is a job for professionals. Homes in Rockcliffe Park, Sandy Hill, and the Glebe sometimes have 3-5 layers accumulated over decades


• Professional stripping of multiple layers costs $4 to $8 per square foot


• A full room can run $600 to $2,000 but is absolutely necessary for a quality result

Heritage Home Considerations

If your Ottawa home has heritage designation (common in designated Heritage Conservation Districts like Rockcliffe Park, New Edinburgh, Lowertown, and parts of Centretown), be aware that some designated interiors may have guidelines about wall treatments. While most heritage designations focus on exteriors, check with the City of Ottawa's heritage planning team before making significant interior changes to a designated property.

What Happens After Stripping

Once the old wallpaper is removed, the wall needs:

Washing with TSP or sugar soap to remove all adhesive residue

Drying for 24-48 hours (critical in Ottawa's varying humidity)

Repair of any gouges, cracks, or damaged areas

Priming with a wallpaper-specific primer like Zinsser Shieldz or Roman PRO-977

Light sanding for a perfectly smooth bonding surface

This prep work is what separates wallpaper that lasts 15+ years from wallpaper that starts peeling after 2 winters. The Ottawa Paint Contractors in the Ottawa Construction Network directory include wallpaper specialists who handle the full process — stripping, prep, and installation — so you get a result that holds up through Ottawa's demanding seasonal cycle.