Waterproofing 101: Why We Install the Drain Below the Tile

 

At Strip Grate Australia, our collection channel is installed beneath the tiles to integrate

seamlessly with the waterproofing system, ensuring a leak-free shower and protecting your home from structural damage.

This approach is a critical aspect of proper waterproofing design. By installing the drain first, the system can manage not only surface water but also sub-tile moisture. Any water that penetrates beneath the tiles is captured by the waterproofing membrane and directed back into the collection channel.

It prevents water from pooling beneath the surface, reducing the risk of leaks, rising damp, and long-term damage, delivering a smarter, more reliable drainage solution built around performance and peace of mind

Mechanics of failure: Water Pooling and Rising Dam

Traditional shower grate installations – particularly those installed after tiling – can create a range of issues that compromise both performance and long-term durability.

When the shower base is screeded to create a fall, a void must be left for the grate to be installed after waterproofing and tiling are complete. This method can degrade the integrity of the waterproofing system because screeds are prone to cracking and crumbling, making it difficult to achieve a reliable waterproofing detail.

Once tiling is complete, installers are often required to use packers and silicone to support and raise the collection channel to the finished tile height. This can result in an uneven or mismatched finish between the grate and tiles, creating areas where water can pool.

Persistent water pooling not only affects functionality but can also lead to mould growth. Additionally, relying on silicone as a seal between the grate and tiles can act as a barrier, trapping water beneath the tiled surface rather than allowing it to drain correctly. Over time, this trapped moisture can lead to rising damp and structural damage.

This method of installation can also leave a void beneath the collection channel, where water can collect without a clear drainage path back to the puddle flange waste outlet. The result is stagnant water, increased risk of mould, and ongoing moisture issues beneath the shower floor.

 

The Technical Advantage: Waterproofing flange in Place

The integration of a 20mm waterproofing flange into our collection channel is a key design advantage, enabling a seamless connection with the waterproofing system and ensuring a reliable, leak-free installation.

By installing the collection channel first, it allows for precise alignment with both the tile layout and plumbing. The channel can be securely fixed to the shower base and levelled accurately, providing a consistent reference point for screeding. This makes it easier to achieve the correct fall back to the drain while ensuring the finished grate sits flush with the tile surface.

The 20mm flange also offers exceptional installation flexibility. It can be installed into a rebate in pre-formed compressed sheet shower bases, ensuring the flange finishes flush with the substrate before waterproofing, similar to the method used for a puddle flange.

With the screed or substrate finished flush to the waterproofing flange, a strong and continuous bond with the waterproofing membrane is achieved. This eliminates the risk of water pooling and ensures that any sub-tile moisture is effectively captured and directed back into the collection channel.

Shower Grate Installation

 

Advanced Features for Complex Builds: The Breakaway Upstand

Our Strip Grate collection channel is engineered with a snap-off upstand, designed to enhance waterproofing performance in against-wall installations, particularly in situations where a puddle flange cannot be positioned close to the bottom plate of the wall frame.

This feature allows the collection channel to be installed first, directly against the wall framing, followed by the wall sheeting. The upstand is positioned behind the wall sheeting, creating an additional barrier that improves waterproofing integrity in critical junctions.

For projects where the combined thickness of wall sheeting, waterproofing membrane, tile adhesive, and tiles exceeds the 20mm flange thickness, the snap-off upstand can be easily removed. This provides the flexibility to accommodate varying build-ups while still maintaining proper waterproofing detailing.

Designed with on-site adaptability in mind, the breakaway upstand offers installers greater control, precision, and confidence, making it an ideal solution for more complex bathroom builds.

Built by Licensed Waterproofers, Trusted by the Trades

As licensed waterproofers, we’ve seen firsthand the damage caused by poorly designed and incorrectly installed drainage systems, water pooling, leaking drains held together with silicone, rising damp, mould, and ongoing blockages.

That’s why we engineered a solution designed to address both plumbing and waterproofing. Our system is made for straightforward installation, while eliminating the common issues associated with traditional grate setups.

For plumbers, tilers, and builders, this means no reliance on packers or silicone to create a water seal, provide support, or hold the system in place. Instead, our integrated design ensures a secure, stable, and watertight installation from the outset.

Our grate systems are tested to Australian standards, hold WaterMark certification, and are backed by a comprehensive 10-year warranty, delivering confidence, reliability, and long-term performance on every project.



FAQ’S

Q: Do I need to use silicone to support a Strip Grate?

A: No, our Strip Grates do not require packers or silicone for support to stay in place, as our collection channel is waterproofed before tiling to ensure a leak-free environment. 

 

Q: What is the correct gap to leave between the grate and the tile?

A: When cutting your tile, you must allow for an equal 5mm gap. This is achieved by tiling to the inner edge of the waterproofing flange. Tiles mustn’t overhang into the collection channel, ensuring proper drainage performance.



Q: How do I connect the collection channel to existing plumbing?

A: The collection channel easily glues together and becomes part of your plumbing system by connecting directly to your standard 50mm PVC S-Trap or an 80/100mm PVC outlet.



Q: How do Strip Grate systems prevent water pooling?


A: Our collection channel is installed before tiling and waterproofed into place, allowing both surface and sub-tile water to drain back into the system, eliminating stagnant water and reducing the risk of mould and damage.



Q: Do your grates require silicone or packers for installation?


A: No. Our system is designed to be securely installed without the need for packers or silicone for support, ensuring a more reliable and watertight solution.

Q: What is the benefit of the 20mm waterproofing flange?


A: The integrated 20mm flange allows the collection channel to be fully waterproofed into the substrate before tiling, creating a strong bond with the membrane and preventing leaks or sub-tile water buildup.



Q: Are your products compliant with Australian standards?


A: Yes. Our grate systems are tested to Australian standards and hold WaterMark certification, ensuring quality, safety, and performance.

 



Summary

Strip Grate Australia designs innovative, easy-to-install linear shower grates and drainage systems that combine sleek aesthetics with superior waterproofing and leak prevention. Trusted by builders, architects, and homeowners alike, our certified products are backed by a 10-year warranty, delivering long-lasting performance and complete peace of mind.