Shower trays and wastes: acrylic, stone resin and tiled floors

A shower tray looks simple: a shaped base with a hole in it. Underneath is a waste and trap, a connection to the waste pipe and, on a good installation, some way to reach them. This guide explains the main tray types and how they are drained. If your problem is water that drains slowly, start with our blocked shower drain guide instead. A blocked waste and a badly fitted tray are different faults with different fixes.

Types of shower tray

Acrylic or capped trays. Lightweight trays, often acrylic over a reinforced base. They are easy to handle and usually cheaper. Some need a full bed or support underneath so they do not flex, because a tray that moves when you stand on it will eventually break the seal around its edge.

Stone resin trays. Heavier, more rigid trays made from a resin and mineral mix with a hard finish. Many are low profile and sit close to the floor, which looks neat but leaves little room for the trap underneath. They need a flat, solid, level base. Some are sold with a riser kit or plinth that lifts the tray to give room for the waste.

Tiled trays and wet room floors. The floor itself is the tray. A former or board with the falls built in sits on the floor, it is tanked with a waterproofing system, and tiles go on top. These suit level access showers. They are a specialist job, because the waterproofing has to be right before it is covered. Our guide to wet rooms and tanking explains more.

Walk-in and linear-drain trays. Large trays or wet floors with a long channel drain along one edge. They look clean, but the channel and its trap collect hair along their length and need regular cleaning.

Wastes and traps

The waste is the outlet in the tray, with a grid or cover on top. Below it is a trap that holds a small amount of water, the water seal, to stop drain smells coming back. From the trap, the waste pipe runs to the drain.

Points worth knowing:

• The waste must match the tray. Many trays have a 90mm waste hole, but not all. The tray maker will say which wastes suit it. Some trays come with their own.
• Low profile trays need low profile traps. A shallow trap holds a smaller water seal, which can be pulled out by other appliances draining, or evaporate if the shower is not used. The product listing will state the seal depth.
• Fast flow wastes suit high-flow showers, but they only help if the waste pipe and its route can carry the water away too.
• Top access matters. Most modern wastes let you lift the grid and pull out a dip tube or hair catcher from above. That is how you clean them. Fixed traps with no top access are harder to look after.

Falls

Water has to run to the waste. A manufactured tray has the fall built in, and it has to be installed level as its maker says, or water will sit in one corner. A tiled or wet room floor has falls formed in the floor itself, and getting those right is part of the specialist installation.

The waste pipe under the tray needs a steady fall to the drain too. A long, flat or dipped run drains slowly and blocks more often. That is a plumber's design question, and it is easier to settle before the floor is finished. Our bathroom refit order guide explains where the tray fits in the sequence.

Access under the tray

Ask, before the tray goes in, how anyone will reach the trap and waste joint in future. On a raised tray, that may be a removable plinth panel. On a low tray, it may be from the room below or by lifting the tray. Some installations leave no access at all, which turns a small leak into a big job.

A leak under the tray

Signs include a stain on the ceiling below, loose or hollow-sounding tiles near the tray, a damp, musty smell, or mould that keeps coming back along the tray edge.

Common sources:

• The waste joint between the tray and the trap.
• The joint with the waste pipe below the trap.
• The seal between the tray and the wall, where silicone has failed or the tray has moved.
• Grout and tiles inside the enclosure letting water through to the board behind.
• Shower valve pipework in the wall.

A simple check: with the shower off, pour a jug of water directly into the waste and look for drips below. Then, separately, wet the walls and the tray edge and look again. That helps separate a waste leak from a seal or tile leak.

Call a plumber if water is reaching a ceiling or floor below, the tray rocks or flexes, the tray is cracked, the leak continues after resealing, or there is no access to the waste. Fresh silicone over a leaking waste or a moving tray only hides the problem; see sealant and silicone. If the ceiling below is wet near light fittings, turn off that lighting circuit and get it checked. For insurance, see leak insurance claims.

A shower trap at Wickes

We haven't tested this. Figures are as the maker states them (checked 13 November 2026).

Is a stone resin tray better than an acrylic one?

Stone resin trays are heavier and more rigid, and many people prefer the finish. Acrylic trays are lighter and easier to handle. Either works if it is properly supported and level. A poorly bedded tray of any type will flex and leak.

Why does my shower tray smell of drains?

Usually the trap's water seal has been lost, either because the shower has not been used for a while or because the seal is shallow. Run the shower for a minute. If the smell comes back quickly, clean the trap and ask a plumber to check the waste pipe and venting.

Can I replace a shower tray without retiling?

Sometimes, if the new tray is the same size and the tiles come away cleanly at the edge. Often the bottom row of tiles, and some of the board behind, have to be replaced. Ask a plumber or fitter to look before buying a tray.