Best Practices for Waterproofing Showers: Featuring AquaCheck

Waterproofing showers is one of the most critical steps in any bathroom construction or renovation. Up to 90% of bathroom-related complaints in Australia stem from waterproofing failures and leaks. 

Shower areas are particularly problematic because water and moisture can seep through barriers into concrete, timber, or metal framing, leading to costly repairs, structural damage, and mould growth.

At Aussie Plasterboard, we’re dedicated to providing top-notch solutions and advice to help you achieve the best results. This blog delves into best practices for waterproofing showers, emphasising the essential role of products like AquaCheck to meet and exceed the requirements of the NCC 2022 (adopted by states and territories on 1 May 2023).

Understanding the Importance of Shower Waterproofing

Leaks in showers not only ruin the appearance of your bathroom but also create an unhealthy living environment. Mould thrives in damp conditions, affecting both air quality and the health of occupants. Over time, water infiltration causes severe structural damage to walls, floors, and surrounding areas.

Key Risks of Poor Shower Waterproofing:

1. Structural Damage: Moisture weakens concrete, wood, and metal frames.
2. Health Hazards: Leaks encourage mould and mildew growth.
3. Expensive Repairs: Fixing water damage often involves removing tiles and damaged substrates.

Proper waterproofing eliminates these risks by creating a watertight system. AquaCheck, a moisture-resistant plasterboard, is an excellent substrate that forms the foundation of a durable shower.

Changes in NCC 2022 Waterproofing Requirements

The National Construction Code (NCC) 2022 introduces stricter standards for waterproofing wet areas. Some key updates include:

1. Waterproofing Height: Shower walls in enclosed and unenclosed areas must be waterproofed to at least 1800mm above the finished floor or 50mm above the showerhead—whichever is higher.
2. Comprehensive Coverage: Waterproof membranes are now required across all water-exposed wall linings in the shower area, not just at junctions or corners.
3. Compliance with Standards: All components must meet AS 3740:2021 and membranes must comply with AS/NZS 4858:2004 Wet Area Membranes.

These updates reinforce the importance of using reliable, water-resistant materials like AquaCheck and following best practices during installation.

Best Practices for Waterproofing Showers

1. Choose the Right Substrate

Selecting a water-resistant substrate is critical. AquaCheck, with its superior moisture resistance and dimensional stability, offers significant advantages over alternatives like fibre cement. Unlike fibre cement, which can shrink or crack over time, AquaCheck remains stable, ensuring a smooth, flat surface for tiling.

2. Prepare the Area

Proper preparation sets the stage for effective waterproofing:

• Clean the area thoroughly, ensuring it is free of dust, oil, and debris.
• Install AquaCheck securely, sealing joints with water-resistant compounds.
• Use a primer to enhance adhesion for the waterproof membrane.

3. Apply a High-Quality Waterproof Membrane

The membrane is your primary defence against water ingress. Best practices include:

• Applying two coats of a liquid waterproof membrane for full coverage.
• Paying extra attention to corners, junctions, and areas around fixtures with sealant or reinforcement tape.
• Allowing adequate curing time between coats, as improper curing is a leading cause of membrane failure.

4. Tile and Grout Carefully

Even with a waterproof substrate and membrane, proper tiling is essential:

• Use water-resistant adhesives compatible with AquaCheck.
• Seal grout lines to prevent moisture penetration.
• Regularly inspect and maintain tiles and grout to avoid leaks.

Addressing Enclosed vs. Unenclosed Showers

Different types of showers have specific waterproofing needs:

1. Enclosed Showers: Bounded by walls or screens, these require waterproofing up to 1800mm and within the enclosure.
2. Unenclosed Showers: Open on one or more sides, these require horizontal waterproofing up to 1500mm from the water source and vertical coverage up to 1800mm.

The Role of AquaCheck in Shower Waterproofing

AquaCheck is a high-performance plasterboard that is water-resistant, durable, and easy to install. Its dimensional stability and smooth surface make it ideal for tiled wet areas. Unlike fibre cement, AquaCheck does not expand or contract with humidity, reducing the risk of cracks and ensuring long-term durability.

Key Benefits of AquaCheck:

• Minimal water absorption.
• Compliance with Australian standards for wet areas.
• Easy handling and cutting for efficient installation.

By using AquaCheck in your shower, you build a robust foundation that complements waterproof membranes and finishes.

Waterproofing Membranes and NCC Compliance

The NCC emphasises the importance of seamless membranes to prevent leaks. Membrane failures are often caused by:

• Inadequate priming.
• Poor installation or curing.
• Structural movement.

By adhering to the NCC 2022 guidelines and ensuring full waterproof membrane coverage, you can avoid these common issues.

Choosing Sealants and Joint Compounds

Waterproofing is an all-or-nothing process. Even minor gaps can compromise the entire system. Use high-quality sealants to ensure a watertight finish. For AquaCheck installations, we recommend durable, water-resistant jointing compounds to protect corners, fasteners, and joints.

Avoiding Common Waterproofing Mistakes

1. Skipping Primers: Always apply a primer before the membrane for strong adhesion.
2. Inadequate Coverage: Use multiple coats of membrane to ensure durability.
3. Ignoring Maintenance: Periodically check tiles, grout, and sealants for wear or damage.

In summary

Shower waterproofing is non-negotiable, and cutting corners can lead to significant consequences. By following NCC 2022 guidelines, using high-quality products like AquaCheck, and adopting best practices, you can ensure a durable and watertight bathroom.

At Aussie Plasterboard, we provide the materials and expertise you need for professional waterproofing results. Whether you’re a contractor or a DIY enthusiast, visit our Perth store for AquaCheck and other premium products.