How to make a wet room

A wet room can make a great addition to any home, but it’s important that you either hire a professional or follow a guide, as a lot can go wrong if any mistakes are made. This is a guide to building your own wet room safely and following British Standards, so you can get the best out of your wet room.

Equipment and preparation

Before you build your wet room, it is critical to make sure that the room you want to convert is suitable, this means checking that the following:

• Make sure the floor won’t move, otherwise this will lead to leaks down the line.
• Check the walls aren’t prone to excessive movement
• That the walls do not have a flaky surface.
• Check that the floor has a natural fall or gradient, as water will need to be directed to the drain.

The surfaces will be clean from debris, grease, and dust before any work is carried out.

It’s also good to understand that wet rooms are only as waterproof as the surface used to line them, such as porcelain tiles, backer boards, ceramic tiles, and latex coverings; these surfaces will not remain waterproof unless the above room features are in place.

You’ll also need the proper equipment to carry out this job, such as:

• A spirit level
• Tape measure
• Pencil
• Concrete breaker
• Silicone sealant
• Silicone sealant gun
• Tiles
• Tile grout and adhesive
• Wetroom shower tray
• Waste outlet
• Concrete self-levelling screed

Make sure you’ve measured the area of the floor so you know how much material you need to get, and that you have planned the layout of the wet room on a piece of paper, to keep as a reference whilst working.

How to install a wet room on concrete flooring

The challenging thing about creating a wet room floor whilst you are working on a concrete base such as a ground floor slab is installing the drain pipe which takes the wastewater away.

Typically, this is carried out by using a concrete breaker to dig a drainage channel through the floor, with a large hole where your waste outlet will sit.

• The drainage channel needs to lead directly towards an outside wall in order to avoid digging up any other floors in other rooms. Once the drainage channel is outside of the building, the drain can be laid to an existing manhole.
• The top of the new drainage channel should be laid flush with the finished level of the concrete floor of the wet room. This is so that any tanking can overlap the channel, which will ensure that the water runs straight into the drain and cannot seep between the edge of the floor and the upstanding drain pipe.
• The pipe should also be trapped in the normal way to avoid foul gas running back into the wet room, which would be unpleasant. It is typical to see a horizontal waste trap in a concrete-floored wet room.
• Outlet plates and floor grids lead directly down into the trap below, plates and grids sit on top of the tanking and direct any water into the waste trap whilst holding hairs and other debris for cleaning. If any water seeps under the grid or plate, it will of course go directly into the trap.
• Any drains, not just this one, should be laid in accordance with British Building Regulations and if you make any alterations to existing drain runs or access chambers and manholes, you will need to report these changes to the Building Control Department of your local council, otherwise, you will be violating the regulations in place.
• The channel that houses the drain will need to be concreted over, and a fall for the water is formed into the floor by using the self-levelling floor compound which is thickened slightly with sharp sand.
• You will not need to create a steep slope as water will find its way to the lowest level. A 10mm fall over 2m is sufficient for a wet room.
• The floor plate is positioned in such a way that the pipe goes down into the trap. The waterproof tanking is applied over the plate as are the tiles, and a grid is then fitted into the top of the floor plate.