How to fit a resin shower tray, step by step

What you need

• 60 cm spirit level
• Tape measure and pencil
• Notched trowel and pointing trowel
• Bucket and mixing paddle for the mortar
• Rubber mallet
• Drill and tile bit if the shower screen has to be fixed
• Sealant gun
• Masking tape
• Gloves and safety glasses
• Resin shower tray with mineral filler (Roca Terran, Gala, Sanindusa or the Sensea range at Leroy Merlin)
• 90 mm waste with trap, compatible with the tray height
• Flexible tile adhesive mortar or levelling mortar (Weber, Mapei)
• Waterproofing tape (Mapei or Sika) if there are joints with an untiled wall
• Anti-mould sanitary sealant: Sika, Pattex Baño Sano or Ceys
• 40 mm PVC pipe and coupling if the waste has to be extended
• Cloths and isopropyl alcohol to clean before sealing

Step by step

1. 1

   Measure the space and the waste pipe

   Measure the width and length of the space at three points, because walls are almost never square. Also measure the distance from the waste pipe to each wall. The tray needs an outlet in a position that matches, or that allows a trap with an elbow. Note the height of the waste pipe above the floor.

2. 2

   Choose the tray and the waste

   An extra-flat tray (2.5-3 cm) needs a lower waste pipe and a low-height trap. A standard tray (4-5 cm) is easier to fit over an old installation. A 90 mm waste and a 40 mm outlet pipe are the norm. Keep the delivery note in case sizes need changing.

3. 3

   Remove the old tray if there is one

   If the old tray is resin or acrylic, it comes out by cutting the perimeter sealant with a blade. If it is a tiled built-in one, that is demolition and is quoted as a refurbishment. Before anything else, turn off the water and protect the waste pipe with a cloth.

4. 4

   Clean and check the waste pipe

   Remove remains of cement and sealant. Check that the pipe is whole, with no cracks, that it drains well and that its height allows for the new trap. Pour in a bucket of water to make sure it does not block; if it does, see how to unblock a shower drain.

5. 5

   Dry-fit the tray

   Place the tray in position without mortar. Check that it fits, that the outlet lines up with the waste pipe and that there is 2-3 mm of gap at each wall for the sealant. Mark the perimeter in pencil.

6. 6

   Fit the waste to the tray

   With the tray resting on a cloth, put the rubber seal underneath and the grating on top. Tighten by hand and give it a quarter turn more. Connect the trap and check that the pipe lines up with the waste in the wall or floor.

7. 7

   Prepare the bed with mortar

   Mix the adhesive or levelling mortar until it is firm. Spread it in ribbons where the tray will sit: edges, centre and around the waste. Do not leave it only at the perimeter; the tray has to be supported over its whole surface or it will creak.

8. 8

   Bed down and level the tray

   Place the tray in position, press down with both hands and tap gently with the rubber mallet. Check with the level in both directions. The fall is already built into the tray; what you must achieve is that it is level with respect to the floor.

9. 9

   Connect the waste and test for leaks

   Connect the trap to the pipe. Pour five litres of water into the tray and check underneath that no joint drips. If there is a leak, take it apart and reseat the seal before going on.

10. 10

    Seal the perimeter

    Clean with isopropyl alcohol, put masking tape on both sides of the joint and run a continuous bead of anti-mould sanitary sealant between tray and tile. Smooth it with a finger wetted in soapy water and remove the tape before it cures.

11. 11

    Do the watertightness test and wait

    Plug the waste, fill the tray with 2 cm of water and mark the level with tape. An hour later, the level should not have dropped. Unplug and check that it drains quickly. Do not fit the shower screen until 24-48 hours have passed, so the mortar and sealant can cure.

Which tray to choose and what to measure before you buy

The resin shower tray with mineral filler (the matt white one you see in almost every refurbishment) is today's standard choice for its price, its non-slip surface and how easy it is to clean. It is sold in standard sizes from 70 to 90 cm wide and 100 to 180 cm long, and many can be trimmed with an angle grinder and a diamond blade if the space does not match.

Before buying, measure the space, the position of the waste pipe and the height of the pipe above the floor. That last figure decides whether you can fit an extra-flat tray or whether it has to be a standard-height one.

How to fit a resin shower tray properly: waste, level and watertightness

A properly fitted shower tray meets three conditions. First, it is bedded over its whole surface, not just resting on the edges, because if there is a void it will creak and end up cracking. Second, it is level, so the water goes to the waste without puddles. And third, it does not leak: the two critical joints are the trap and the perimeter sealant.

If you want to swap one resin tray for another of the same size, it is the simplest job. If you want to replace a bath with a tray, the waste pipe changes height, and the bath has to be removed, the floor levelled and the walls tiled. That building work is done by a renovation firm we collaborate with; our part is the shower screen, the mixer and the sealing, as we explain in how much it costs to swap a bath for a shower.

Once the tray is in, the next step is the shower screen. See the guide how to fit a front sliding shower screen and, for the sealing, how to seal a shower screen.

Common mistakes when fitting a shower tray

• Resting the tray only on the perimeter. With no mortar in the middle, the tray flexes, creaks and cracks within a year.
• Gluing with sealant instead of mortar. Sealant seals, but it does not carry weight or level.
• Not testing the trap before bedding down. A leak after levelling means lifting the tray.
• Buying an extra-flat tray with a high waste pipe. If the pipe has no fall, the water stands and smells.
• Fitting the shower screen without letting it cure. The mortar takes 24-48 hours and the screen weighs 25-40 kg.
• Forgetting waterproofing tape on untiled joints. Damp gets into the wall and shows up as mould marks in the next room.

When to call a professional

Fitting a tray over a waste pipe that is already well placed is done by a handyman with basic tools. It stops being handyman work when the waste pipe has to be moved, the floor opened, a bath removed or tiling done. That is building work, and a renovation firm does it.

At Manitas Costa we do not have a set fixed rate for fitting a tray, because it depends on the condition of the waste pipe and the floor. We quote from a photo and measurements: normally, half a day of handyman time (€120-150), plus the shower screen (€90-140 for a front sliding one and €110-170 for a corner one) and, if the old one has to be removed, €50-65. If you need a bath swapped for a shower, the building work runs between €1,100 and €2,400 with our partner firm.

All the details are in shower screen and shower tray installation and shower screen prices. For your area: shower screens in Alicante and shower screens in Valencia. We do not touch gas or boilers; if there is a water heater in the bathroom, a registered installer checks it.

Damp, limescale and salt air: the tray on the coast

In Torrevieja, Benidorm or Alicante, humid air and limescale in the water punish the tray's sealant joint. Always choose a good-brand anti-mould sanitary sealant and renew it every four or five years. If the perimeter starts to go black, we explain it in how to remove mould from the shower.

In second homes, the tray trap dries out during the months of absence and starts to smell. When you arrive, run the water for a few minutes and pour a glass of water down the waste. And if the tray is new, learn early how to clean a resin shower tray without scratching it.