Waterproofing is invisible once the tile is set. It's also the single most important part of any shower installation — the difference between a bathroom that holds up for 20 years and one that starts destroying your walls after three. We take it seriously because we've seen what happens when it's skipped.
Every wet area we tile — shower floors, shower walls, tub surrounds, steam showers — gets a proper waterproofing assembly. Not just cement board. A membrane system that creates a true barrier so water that penetrates the tile surface has nowhere to go except down the drain.
Why Tile Alone Doesn't Waterproof a Shower
This is the most important thing to understand about shower installation: tile and grout are not waterproof. They slow water. They don't stop it.
Over time, grout joints develop micro-cracks. Water works its way through. If there's no membrane behind the tile, it soaks into the cement board, then the wall framing, then the floor structure. That's how you get mold inside walls, tiles falling off a surface that looks fine from the front, and structural rot that requires far more than a tile repair to fix.
A waterproof membrane applied behind and under the tile assembly means that even if grout cracks or a joint opens, water hits the barrier and drains to the drain — not into your home.
Waterproofing Systems We Use
Schluter Kerdi
Sheet membrane applied directly to the substrate in unmodified thinset. Kerdi creates a continuous waterproof layer across shower walls and the pan. Kerdi-Band reinforces corners, changes of plane, and the seam between the pan and the walls — the highest-risk areas in any shower assembly. It's one of the most reliable systems available and our most commonly specified method for new shower builds.
Liquid-Applied Membranes
Brush- or roller-applied membranes cure into a seamless waterproof layer. Useful for complex geometries, repairs, and situations where sheet membrane installation is difficult. Applied in multiple coats with full cure time between each. We use these on shower repairs where existing substrate can be retained and on custom configurations that don't suit sheet systems.
DITRA and DITRA-HEAT
For floor installations, DITRA provides uncoupling and waterproofing simultaneously. The membrane isolates the tile assembly from subfloor movement while keeping the assembly waterproof. DITRA-HEAT adds the heating cable channel to this system — waterproofing, uncoupling, and radiant heat in a single product.
Waterproofing for Shower Repairs
If you have an existing shower showing signs of water infiltration — soft spots in the floor, tiles popping, grout that deteriorates faster than it should, a musty smell that doesn't go away — the waterproofing has either failed or was never there to begin with. Silicone over cracked grout is not a repair. It delays the inevitable while the damage continues behind the tile.
We assess what's actually happening, demo what needs to come out, and rebuild the assembly correctly. Sometimes that's a localized repair. Often it's a full shower rebuild — and we'll tell you honestly which one your situation calls for.
Frequently Asked Questions
Isn't cement board waterproof?
No. Cement board is water-resistant — it won't fall apart when wet, but it absorbs water and allows it to pass through. It's an appropriate substrate for tile, but it is not a waterproofing layer. A membrane system applied over the cement board is what creates the waterproof barrier.
How do I know if my shower is leaking?
Signs include: soft or spongy spots in the floor outside the shower, water staining on ceilings below the bathroom, tiles that sound hollow when tapped, grout that deteriorates rapidly between cleanings, or a persistent musty smell. Any of these warrants investigation before the damage spreads.
Does every shower need a membrane, or just some?
Every shower needs a waterproof membrane — full stop. There are no exceptions for "dry" showers, low-use showers, or basement showers. Water doesn't care how often you shower; it finds every gap eventually.