A bathroom renovation in Montreal is rarely a weekend project. It's three to five weeks of coordination, a budget that can double if the plumbing hides a surprise, and a handful of decisions that — if taken lightly — turn a renovation into a construction site. Here's the guide we give our clients before they sign the first contract.
We cover: real 2026 price ranges, a week-by-week schedule, and the five mistakes that blow up budgets — mistakes we see too often, sometimes after the fact, when the client calls us to fix somebody else's work.
2026 Montreal budgets — the ranges that match reality
Forget articles quoting 2019 prices. Here's what a renovation costs today, labour and materials included, for a standard bathroom (8 ft × 6.5 ft):
- Entry level ($8,000 – $12,000) — Standard acrylic tub, 12×24 ceramic, prefab vanity, mid-tier faucets. Existing plumbing kept.
- Mid range ($15,000 – $22,000) — Walk-in shower with Schluter membrane, large-format porcelain, custom vanity, radiant floor heat, upgraded ventilation. This is the comfort zone for most clients.
- High end ($30,000 – $55,000+) — Space expansion (wall removed), freestanding tub, dual-head shower, Hansgrohe/Kohler fixtures, custom glass partition, tankless water heater, full PEX re-plumb.
These ranges exclude surprises. In a Plateau or Hochelaga triplex, we often find a corroded cast iron drain behind the wall. Budget a 10–15% buffer for whatever comes out behind the drywall.
Realistic schedule: 3 to 5 weeks, not 10 days
TV shows lie. Here's an honest calendar for a mid-range bathroom:
- Week 0 (before demo) — Plans, material selection, orders (some tiles have 3–8 week lead times). Don't demo until everything is delivered.
- Week 1 — Demolition, discovery, plumbing rough-in adjustments. This is when a suspected hidden leak becomes real.
- Week 2 — Final plumbing, electrical, heated floor, shower waterproofing, first 24-hour flood test.
- Week 3 — Tile, grout, glass, paint.
- Week 4 — Fixtures, faucets, vanity, final adjustments.
- Week 5 (buffer) — Touch-ups, deficiency list, final inspection.
Mistake #1 — Skimping on waterproofing
The waterproofing membrane (Schluter Kerdi, Noble, or equivalent) costs $400–$900 for a standard shower. Some contractors skip it or swap it for tar paper to save money. That's the fastest path to a leak in the neighbour's ceiling — and a call to (514) 655-6560 eighteen months later.
Demand a certified membrane, installed with proper corner banding and joint sealing. Ask for photos before tile goes down.
Mistake #2 — Undersizing the plumbing
A ½" shower drain when code calls for ¾". A 3/8" supply line to a tub that needs a fast fill. It sounds technical — it creates slow drains and weak pressures that turn into daily irritants for ten years.
A CMMTQ plumber sizes correctly per the Quebec Plumbing Code. A handyman doesn't always. It's one of the reasons our how to choose a good plumber guide insists on verifying licences.
Mistake #3 — Forgetting ventilation
A bathroom without a minimum 80 CFM fan (or 50 CFM continuous) becomes a mould incubator in eighteen months of Montreal humidity. Add a humidity sensor that turns the fan on automatically: $150 that saves $5,000 in redone grout joints and baseboards.
The fan must vent outside, not into the attic. Check for a roof vent.
Mistake #4 — DIY plumbing
In Montreal, any modification to the pressurized plumbing system (hot/cold supply) must be done by a CMMTQ-licensed plumber. That's not an opinion — it's provincial contractor licensing law. A non-compliant installation voids your home insurance in the event of water damage.
You can tile your own bathroom. You cannot hook up your own shower valve.
Mistake #5 — Changing your mind mid-project
"Actually, we want to move the toilet." That sentence in week 2 doubles the cost of an entire slice: breaking the slab, rerouting the 3" sanitary drain, redoing waterproofing. A change that would cost $200 at the design stage costs $3,500 at the slab pour stage.
Spend two extra weeks in design. Draw it. Change your mind ten times on paper. Sign the plans. Don't touch them again.
Permits — when do you need one in Montreal?
In Montreal, a permit is required if you relocate a plumbing fixture, change the room's footprint, or modify the structure. Redoing a bathroom in place (without moving drain or vent) generally doesn't require a permit — but a serious plumber will tell you during the quote.
Summary — the pre-demo checklist
- Budget ×1.15 buffer
- Plans signed, materials delivered, before the first swing of the hammer
- CMMTQ + RBQ contractor, detailed written quote
- Certified waterproof membrane, photos before tile
- ≥ 80 CFM ventilation, vented outside
- Permit if plumbing fixture relocated
Plomberie PSF handles the full plumbing scope of your bathroom renovation — rough-in through final faucets — coordinating with your designer and general contractor. Over ten years in Montreal, CMMTQ member, work guaranteed. For a written quote on your project, call (514) 655-6560 or go through /contact. We call you back the same day.