Waterproofing Systems
The layer that decides whether your shower lasts 5 years or 50.
Every shower we build is fully waterproofed — without exception. It's the single most important thing a tile contractor does, and the single thing most contractors get wrong.
Why It Matters
Tile and grout are not waterproof.
This is the most misunderstood fact in residential renovation. Grout is porous — water moves through it, slowly but constantly. Without a true waterproof membrane sitting behind the tile, your shower wall cavity is getting wet every time someone showers. Over 5–15 years, that water rots studs, grows mould, and eventually leaks into ceilings below.
The fix is straightforward, and it's what separates a quality tile installer from a fast one: a bonded waterproof membrane on every wall, every floor, every curb, every bench — on every single shower.
Two Systems
Sheet membrane vs liquid membrane.
Schluter KERDI
Polyethylene sheet membrane with a fleece bonding layer on both sides. Adhered to the substrate with thinset, seams overlapped 50mm and sealed with KERDI-BAND.
Why we use it
- ✓Predictable, uniform thickness
- ✓Inspectable — you can see and photograph every seam
- ✓System-engineered: drains, niches, corners all match
- ✓30+ year manufacturer track record
RedGard Liquid
Roller-applied elastomeric membrane that cures into a continuous waterproof film. Two coats minimum, brushed reinforcement at corners.
Where it shines
- ✓Tight retrofits with complex penetrations
- ✓Curbless detail work
- ✓Repair / overlay of existing waterproof layers
- ✓No seams — fully monolithic when applied correctly
Wall Assembly
What a properly built shower wall looks like.
◆ Layer 3 is the difference. Without it, water passes through layers 1-2 and saturates layers 4-6.
Common Failure Modes
The six reasons we see tiled showers fail.
No waterproof membrane
Greenboard or cement board alone allows water through grout into the wall cavity. Most common failure we see.
Missing pre-slope
Without a pre-sloped mud bed under the pan liner, water pools and saturates the substrate.
Subfloor deflection
Floors that flex crack tile and tear membrane seams. We check L/360 minimum, L/720 for stone.
Wrong mortar for tile
Standard thinset under large-format panels causes voids — water entry points within months.
Unsealed penetrations
Mixer valves, shower heads, and accessories left unsealed are the most common leak source.
Rushed grout cure
Grout sealed too early traps moisture. We follow manufacturer cure times — always.
Get Started Today
Have a shower you're worried about?
We do free assessments. If it needs fixing, we'll quote it. If it doesn't, we'll tell you.