Services
No services match that search.
Browse by type
ChecklistsCompared honestlyWhat everything costsDecision guidesQuestions & answersPlain-English glossaryGuides & how-tosSomething wrong at home?Research & dataCalculators & tools BlogMore
Full services directory How it worksFor prosAbout Get matched Call (866) 582-8523Tile is not waterproofing. Grout is not waterproofing. A continuous membrane — detailed at corners, niches, benches and drains — is what keeps shower water out of your joists. This is wet-area work, not basement damp-proofing.
Bathroom waterproofing creates a continuous water-resistive envelope in wet zones — primarily showers, tub surrounds and sometimes entire wet rooms — using sheet membranes, liquid-applied systems or proprietary board systems. It is detailed at every change of plane and at the drain, then covered by tile or other finishes. It is not the same trade as below-grade foundation waterproofing. Name the system, photograph it, then tile — in that order.
Define the wet zone and the flood plane
Waterproofing extent should match how the room is used — shower enclosure only, tub deck, or full wet-room floor. Curbless designs extend membrane beyond the old "shower box" idea. Draw the limit so trades do not stop the system at an imaginary line.
Watch for: Membrane stopped halfway up a wall that body sprays will soak daily.
Prepare substrate: stable, compatible, and correct for the system
Cement board, foam board systems or other listed substrates must be installed to the membrane manufacturer's requirements. Movement, soft spots and incompatible surfaces cause membranes to fail even when the liquid looks evenly painted on.
Watch for: Standard drywall or moisture-resistant drywall sold as a shower substrate. It is not a waterproofing system.
Detail corners, penetrations, benches and niches first
Preformed corners, reinforcing fabrics, sealant bands and manufacturer accessories exist because field folds fail. Pipe penetrations and mixing-valve boxes need intentional detailing. Benches and niches are classic leak origins when treated as afterthoughts.
Watch for: Liquid membrane brushed thin at inside corners with no reinforcement. Corners move; thin films crack.
Integrate the drain — the highest-risk junction
Clamping drains, bonding flanges and linear drain assemblies each have a required membrane interface. The pan must fall to the drain continuously. A perfect wall membrane with a bad drain detail still floods the ceiling below.
Watch for: A drain chosen after the pan was built, forcing improvisation at the most critical joint.
Apply the field membrane to thickness and continuity
Sheet systems need correct seams and seams primers where specified. Liquid systems need listed thickness — often in multiple coats — with cure time between. Photograph every stage with date stamps before tile covers the evidence.
Watch for: One thin coat the colour of hope, tiled the same afternoon against manufacturer cure times.
Flood test or otherwise verify before tile
Where the system allows, flood-test pans and document results. Fix failures now. Tile does not rescue a membrane holiday; it conceals it until the drywall downstairs announces it.
Watch for: Pressure to skip testing because the tile setter is booked tomorrow. Rebook the setter.
Protect the membrane through tiling and cure
Tilesetters must not puncture the envelope with reckless fasteners or grind through corners. Movement joints at changes of plane remain sealant, not rigid grout. After handover, homeowners maintain caulk as a surface seal — not as the primary waterproofing.
Watch for: Grab-bar fasteners driven into unknown backing through the wet wall without sealed, blocked attachment details.
Waterproofing materials for a typical shower are often a modest share of remodel cost; labour and detailing drive the number more than the bucket of liquid. Failures that reach framing become structural repairs far above the original membrane line item. Specify the system by name and require photos before tile.
See the full bathroom waterproofing cost guide — by material, size and region →
Everyone else ranking for this is paid when you say yes. Here's when you shouldn't.
A failed shower membrane can rot joists and grow mould in cavities you cannot see. This is not a weekend caulk project when structure is wet.
Which waterproofing system will you use, by product name?
Named systems have methods and accessories. "We seal it" does not.
Will you photograph the finished membrane before tile?
Your only record of the concealed envelope.
How do you detail the drain, niches and any bench?
Those three details cause a disproportionate share of failures.
Do you flood-test, and who signs off?
Testing discipline separates pros from speed crews.
What substrate will the membrane go over?
Wrong substrate voids systems and shortens life.
Local pro matching for bathroom waterproofing is rolling out by metro. Enter your ZIP and we'll match you with vetted pros in your area today.
Tell us what you need and we'll match you with vetted local bathroom remodeling pros — free.
Free · No pressure · Licensed & insured pros