Creating a Wet Room – Some Additional Advice
Hopefully you have read the previous post about preparing for creating a wet room by waterproofing the walls and floor. Clearly getting the waterproofing of the walls and floors right is critical to the success of your new wet room (and that doesn’t just mean laying porcelain tiles and using waterproof grouting) but there are also some other important aspects to consider.
One important aspect is the choice of grout – not all grout is waterproof so you will have to choose a polymer modified grout (there are a number of different makes on the market such as BAL and Ardex). But water resistance is not the only feature of a grout that is important – with many power showers now generating very forceful jets of water, the grout has to also be able to withstand a daily battering from strong blasts of water. If you are in any doubt about the type of grout to use then talk to a specialist tiling company.
Wet Room Shower Tray
Another important part of the wet room is the shower tray – a wet room shower tray is usually installed so that it is level with the tiled floor surface. This can be achieved in 2 different ways:
- Lay the shower tray on top of the existing concrete or wooden floor and then raise the surrounding floor levels using waterproof tile backer boards. The only potential problem with this is that the wet room floor level may not be the same level as the floor of the room or hallway immediately outside. This will require the wet room door to open outwards and there will then be a step up at the entrance.
- Cut into the existing floor so the shower tray can be set in to be level with the existing floor. Depending on the floor type, the tray may need to be supported from underneath.
Another alternative is to create a stepped area around the shower tray only. When done well this can become an attractive design feature of your wet room.
Wet room shower trays are preformed with the correct slope towards the drain to ensure water always drains quickly even from the most powerful of showers. They can even be cut to suit awkward spaces and the floor tiles can be laid directly onto the shower tray without any additional preparation. The advantage of using a wet room shower tray is to avoid having to calculate and prepare the correct slope for good drainage.
Wet Room Drainage
The drain itself needs to be carefully chosen as the most suitable type will depend on the depth available beneath the floor. Some drain traps have a shallow profile where floor depths are limited but if the installation area is not limited by floor depth (in a newly built room, for example) then a fully vertical drain outlet will offer better, quicker drainage of water.
Some shallow drainage traps such as those from Valsir can be installed in a space with a depth of only 70 mm yet still produce a flow rate of 0.8 litres/second which is double the flow rate required by the European Standard EN 274.
Underfloor heating is a necessary luxury in a wet room – not only does it make the floor a pleasant temperature to walk on in all weathers but it also helps to quickly dry the tiles and avoiding a slippery floor.
There are two different types of underfloor heating: electric heating, which uses cables or a mat, laid directly on top of the waterproof membrane or a system of pipes that works off the main central heating system.
Electric underfloor heating is usually easiest to install in an old house because it is easy to install over an existing floor and requires a thermostat and timer to control the heat. The disadvantage is that it can be expensive to run.
A central underfloor heating system uses pipes containing hot water in the same way as radiators work so it is easier to control and less expensive to run (off gas or oil) but is more difficult to install in an existing room as the pipes need to be installed under the floor. It is better suited to a newly built wet room.