How do I waterproof a shower properly?

Proper shower waterproofing requires a multi-layer approach with vapor barriers, waterproof membranes, and careful attention to penetrations and corners - it's critical work that protects your entire home from water damage.

The foundation of shower waterproofing starts behind the walls with a vapor barrier (6-mil polyethylene plastic) installed between the studs and drywall or cement board. This prevents moisture from reaching the framing. Over this, you'll install cement board (like Hardiebacker) rather than regular drywall, as it won't deteriorate when exposed to moisture.

The next critical layer is a waterproof membrane applied directly to the cement board surface. In Ottawa's climate, liquid-applied membranes like RedGard or Mapei AquaDefense work well and can handle our temperature fluctuations. These products create a seamless barrier that's painted on with a roller. Pay special attention to corners, where walls meet the tub or shower pan, and around any penetrations like faucet valves or shower niches. These areas need extra coats and often fabric reinforcement strips.

Shower pan waterproofing is equally crucial. For tile showers, this typically involves a pre-slope, waterproof liner (CPE or PVC), and proper drain assembly with weep holes. The liner must extend up the walls at least 6 inches above the curb height. Many contractors in Ottawa now use modern systems like Schluter-Kerdi or similar integrated waterproofing systems that combine the membrane and drain components.

Ontario Building Code requirements mandate proper waterproofing in shower areas, and while permits aren't always required for shower renovations, the work must still meet code standards. This protects you from insurance issues if water damage occurs later. The Electrical Safety Authority (ESA) also requires GFCI protection for all bathroom electrical, which should be coordinated with your waterproofing work.

Professional installation is strongly recommended for shower waterproofing. A failed waterproof system can cause tens of thousands in damage to floors, ceilings below, and structural elements. The materials cost only a few hundred dollars, but the labor requires experience with proper techniques, especially around drains and corners where most failures occur.

For a comprehensive shower renovation with proper waterproofing, contact Justyn Rook Contracting for a free consultation - we'll ensure your shower is protected against Ottawa's humidity and temperature changes for decades to come.