How to install a linear shower grate

🔧 Installing a Linear Shower Grate in an Australian Bathroom Renovation

Plumbing work in Australia must be performed by a licensed plumber. This guide explains the process and helps you select the right tools and materials.

What is involved in installing a linear shower grate in Australia?

A linear shower grate installation requires accurate set-out, compliant waste connection, correct falls, and close coordination with waterproofing and tiling trades. In Australia, the installation must comply with the PCA, AS/NZS 3500.2 for sanitary drainage, and relevant waterproofing requirements under AS 3740.

Linear drains are commonly used in walk-in showers and premium bathroom renovations because they allow a single directional floor fall and a cleaner architectural finish. Correct placement, outlet sizing, and finished floor height are critical to avoid ponding, leakage, and tile alignment issues.

What skill level is required for linear shower grate installation?

Advanced — Estimated time: 1-2 days plumbing installation, plus coordination with waterproofing, screeding, and tiling trades

What tools are required for linear shower grate installation?

What materials are needed for a compliant linear shower grate installation?

Safety Requirements

Step-by-Step Guide

Step 1: Assess layout, compliance, and drain selection

1️⃣ Confirm shower design and drain type

Review the bathroom plans, finished floor build-up, tile format, and shower screen layout before starting. Determine whether the linear grate will sit against the wall, at the shower entry, or centrally within the shower zone.

Select a linear drain system with:

For most residential showers, a 50 mm outlet is typical, but higher-flow or larger shower applications may require confirmation of discharge capacity and possibly a larger outlet depending on product certification and hydraulic demand.

💡 Wall-adjacent linear drains are popular because they simplify screed falls to a single plane and improve large-format tile presentation.

Step 2: Set out heights, falls, and finished floor levels

2️⃣ Establish precise levels

Set a datum using a laser level and confirm:

Linear grates should finish flush with the surrounding tile surface. The shower floor must be graded to drain effectively without ponding. Falls to the channel should generally be set to achieve compliant drainage in accordance with AS 3740 wet area requirements and accepted trade practice, commonly around 1:80 to 1:100 within the shower floor depending on tile and design constraints.

Check that the drain body allows enough depth for:

💡 Allow for tile insert grate depth early. This avoids a common issue where the insert tray sits proud or too low after tiling.

Step 3: Rough-in the waste position

3️⃣ Locate and install the sanitary drain connection

Set out the waste point exactly to the manufacturer’s dimensions. Linear drains are not forgiving if the outlet is misaligned even by a small amount.

Install the branch drain in DWV PVC to AS/NZS 1260 and connect in accordance with AS/NZS 3500.2. Maintain grade on the sanitary line and ensure access and trap arrangement comply with the system design and local authority requirements.

Typical rough-in considerations:

Where the drain is installed over concrete, coordinate any recessing or slab penetration with the builder/engineer before cutting. Never cut a post-tensioned slab without engineering approval.

Step 4: Dry-fit the linear drain body

4️⃣ Trial fit and verify alignment

Dry-fit the channel body to the rough-in waste and check:

The channel must be dead level lengthways unless the manufacturer specifies an internal fall design. The surrounding floor screed, not the grate body, provides the directional fall in most systems.

Check that the finished grate edge will align neatly with tile joints and that the drain location suits the waterproofing upturns and shower screen line.

💡 Set out with actual tile modules, not nominal dimensions on paper. This prevents awkward cuts at the grate edge.

Step 5: Secure and support the drain body

5️⃣ Fix the drain at final height

Once set-out is confirmed, secure the drain body so it cannot move during screeding, waterproofing, or tiling. Use the proprietary legs, brackets, packers, or bedding mortar recommended by the manufacturer.

Support is critical under the full channel length to prevent:

Recheck the top edge height with the laser after fixing. The drain rim should match the final tile finish height once adhesive and tile thickness are installed.

Step 6: Make the final waste connection

6️⃣ Connect and seal the outlet

Prime and solvent weld the outlet connection to the sanitary pipework in accordance with the pipe manufacturer’s instructions. Ensure the pipe is cut square, deburred, and fully seated.

Avoid stressing the outlet socket during connection. If needed, adjust support under the pipework so the drain body remains level and the outlet is not carrying pipe load.

After connection:

Step 7: Coordinate waterproofing interface

7️⃣ Prepare for wet area membrane integration

This is one of the most critical stages of the job. The linear drain must be compatible with the wet area membrane system and installed so the waterproofing can terminate correctly into or over the flange detail in accordance with AS 3740 and the drain manufacturer’s instructions.

Coordinate with the waterproofer to ensure:

Do not rely on silicone alone as the primary waterproofing method. The waterproof membrane must integrate properly with the drain flange/proprietary collar system.

⚠️ Waterproofing non-compliance is a major source of bathroom failure and defects. Confirm compatibility between drain brand and membrane system before installation.

Step 8: Screed the shower floor to correct falls

8️⃣ Form the shower base toward the linear drain

Install the screed so the shower floor falls evenly toward the linear grate. One of the main benefits of a linear drain is the ability to create a single-plane fall, especially where the drain is installed along the rear wall or entry.

Check for:

Use a straight edge from the high point to the grate edge to verify the screed profile before it cures.

💡 With large-format tiles, even a minor hollow near the channel becomes obvious after water testing. Always check with a long straight edge, not just a short level.

Step 9: Protect the drain during tiling

9️⃣ Prevent damage and contamination

Before tiling starts, protect the grate frame and channel interior from:

Install the manufacturer’s temporary insert or tape/cardboard protection. Ensure the tiler understands the finished height requirements and that the tile edge adjacent to the drain is straight and fully supported.

Tile cuts at the channel should be clean, with even joint spacing and no unsupported tile overhang.

Step 10: Install grate, seal visible junctions, and clean

🔟 Complete final fit-off

After tiling and grouting are complete and cured as required, install the grate or tile insert panel. Confirm it sits flush, removes easily for maintenance, and does not rock.

Apply sanitary-grade neutral cure silicone only where specified at visible movement or perimeter junctions. Do not block designed drainage paths within the channel system.

Clean out debris from the channel and trap area. Remove all protective films from stainless components carefully to avoid scratching.

Step 11: Test the installation

1️⃣1️⃣ Water test and commission

Carry out a functional test of the linear drain by running water through the shower area and checking:

Where required, perform flood or leak testing in accordance with site QA procedures and applicable trade sequencing.

Record any manufacturer warranty requirements, especially where proprietary drain and waterproofing systems have been used.

Common Mistakes to Avoid

Pro Tips

Recommended Tools

🔒 Licensing

Plumbing work in Australia must be performed by a licensed plumber. This guide explains the process and helps you select the right tools and materials. Licensing requirements vary by state, including NSW Fair Trading, VIC VBA, QLD QBCC, and WA Building Commission.