WetBase® Shower Tray FAQs

A centre drain sits midway between both the long and short edges of the tray. An offset drain sits centrally across the width of the tray but positioned 450mm from one end, rather than in the middle of the length. The choice is usually driven by the need to avoid a joist below the floor, or to position the drain directly beneath the shower head. WetBase® Standard is available in additional drain positions beyond these two — see the plan diagram on each product page for the exact drain location for your chosen size.

WetBase® Standard uses a small square drain in a fixed position. WetBase® Linear instead uses a narrow, rectangular channel drain that runs along most of one edge of the tray. During installation, the drain outlet is positioned along the channel by the installer — giving flexibility to route around joists or other underfloor obstacles without moving the whole tray. The drain cover can also be reversed so it tiles flush with the rest of the floor. Beyond the practical benefit, many customers choose Linear for the cleaner, more discreet look of a channel drain over a central point drain.

WetBase® ships with the Dallmer fast-flow drain, chosen for handling high water volumes efficiently. The drain sits 82mm below the base of the tray, with a 140 × 140mm grate, so it fits comfortably beneath the floor with enough clearance to connect to the waste pipe.

No. The WetBase® only needs to cover the showering area itself — there’s no need to extend it beyond where the shower will be positioned.

Yes — up to 50mm can be trimmed from each edge using a good-quality hand saw. Equal amounts must be removed from opposite edges: for example, if the tray needs to be reduced by 50mm in length overall, take 25mm off each end rather than 50mm from one end alone. This keeps the tray centred correctly on the drain and preserves the pre-formed fall.

Yes. You’ll need to either mount the WetBase® on a raised platform (a step-in installation), or chase a channel into the concrete floor so the drain and waste pipe can be accommodated at the correct depth.

Yes. The WetBase® must be fully supported underneath (under-boarded) before installation, to ensure it doesn’t flex under load — flexing can induce cracking in the tile grout above. We recommend under-boarding with 18mm marine ply panels fitted between the joists or across a supporting platform. See the WetBase® installation instructions for full detail.

A standard 43mm (1½ inch) solvent weld waste pipe, available from any plumbers’ merchant or DIY store, is pushed firmly into the drain outlet supplied with the kit and secured with an appropriate solvent weld adhesive, then connected to the nearest soil pipe using standard jointing products. Once the weld has had time to fully set, test the connection by pouring a cup or two of water down the drain and checking for leaks — before continuing with the rest of the WetBase® fitting.

The tray should be bedded securely using a good-quality flexible tile adhesive, mixed from powder. Buildings move very slightly with the seasons as the ground beneath them shifts, and without a flexible fixing, tiles above the tray can crack or the grout lines can open up over time. Example suitable powder adhesive brands include Weber (Floor Flex or Weberset SPF), Mapei (ProFlex or Keraflex), Granfix, and Larson Proflex — always check current product availability before specifying.

• Never use solvent-based adhesives — they can damage the composition of the tray.
• Never use screws — they will damage the tray and compromise its waterproof properties.
• Never use ready-mixed adhesive — only powder-mixed adhesive should be used. Ready-mixed products contain excess water and shelf-life additives that can delay or prevent proper drying and adhesion.

The full showering area, plus a further 300mm “splash zone” around it, needs to be fully tanked before tiling, along with the walls of the showering area. You don’t need to waterproof the whole room beyond this — unless water is likely to travel further into the room, in which case tanking a larger area is the safer approach.

Floor tiles need a solid, inflexible base to prevent movement over time, which otherwise causes cracked tiles or grout lines. 10mm thermal tile backer board is ideal for this, as it also adds useful insulation — particularly valuable where underfloor heating is being fitted too. The WetBase® tray is approximately 20mm thick, roughly the same as a conventional floorboard, so to achieve a level floor throughout, the surrounding area needs raising by 10mm using tile backer board across the joists and supporting platform. Boarding the wider floor with insulated, taped backer board completes a level, stable, waterproof surface ready for tiling. See the WetBase® installation instructions for full detail.

We recommend mosaic tiles with the WetBase® range, as their flexible backing sheet follows the tray’s contours and ensures water drains away quickly. Larger format tiles can be used but will need an “envelope” cut to maintain the fall to the drain — if in doubt, consult a professional tiler. If large-format tiling without envelope cuts is a priority, our single-fall WetBase® ONE Infinity range is designed specifically to avoid this issue.

Yes. We supply Warmup underfloor heating kits, which are embedded within the tile adhesive bed and are fully compatible with installation over a WetBase® tray.

No — the WetBase® is not designed for point loading, so it isn’t suitable for use with a wheelchair or shower stool. For wheelchair-accessible wet rooms, we recommend the Impey AquaDec EasyFit, AKW Tuff Form or Contour ShowerDec ranges, all engineered to withstand point loading. Call 0800 280 8008 and our team can advise on the right choice for your project.

No — the WetBase® is designed for a tiled finish only. For a vinyl floor finish, we recommend the Impey Level Dec range instead — designed specifically for vinyl and Altro floor coverings, with no under-boarding required.

A waterproofing tanking kit is available as an optional extra alongside every WetBase® range. We supply the Mapei tanking kit — primer, jointing tape and tanking solution — giving a complete, tested waterproofing system for the shower area rather than needing to source components separately. Call 0800 280 8008 for advice on the right quantity for your project.

The Mapei tanking kit includes a liquid tanking solution, jointing tape for every seam, and a primer for porous surfaces. Tape is applied first to each seam where the tray meets the walls or floor, then two to three coats of tanking solution are applied across the shower area and up the walls to splash height, before tiling. See our tanking kit collection for current pricing and coverage.

WetBase® trays are specified for the UK market and backed by a 20-year guarantee, full technical support from our in-house team, and genuine aftercare if you ever need it. That combination of guarantee, support and proven performance is what sits behind the price — not just the tray itself.