Wet room planning – what you need to know
The essential elements of a functional wet room are drainage and watertightness. The rest is pure aesthetic.
A wet room is space saving, sleek and practical. It also has the added benefit of being universally accessible as there is no step to overcome for children and those with mobility issues.
It can turn an awkward area into something functional and beautiful and help a small space feel open and airy. So how do you know if it will work in your home?
Consider the following…
This is the first element to consider. If you cannot achieve sufficient drain-away, do not attempt a wet room!
To ensure the flush to floor finish that is the trademark of a wet room floor, the drain gulley for the shower needs to be installed within the floor. In some cases there may not be enough space within the floor – for example in a suspended floor where the wooden joists aren’t deep enough. There are space saving drains on the market, so this may open up possibilities. There also must be sufficient drop for the water to drain from this point or you will end up with standing water.
From an installation perspective, to ensure the water drains properly there must be a gradient in the floor tiling which slopes down towards the gulley.
You should check the volume of water your shower can produce, and the amount of litres your drain can cope with. It should at the least match, but ideally be capable of draining more than this volume. A pipe diameter of 50mm should ensure a good flow of water away from the gulley, but the length of this run and the gradient of the pipework here should be considered by a professional to ensure this flow rate can be maintained.
The gradient to the gully can be achieved either by purchasing a pre-formed wet room tray that is set into the floor and then tiled (my preferred option) or by manufacturing onsite. The latter offers a more bespoke option, but this carries a higher risk of leakage if your trade gets it wrong.
It is essential to ensure the floor is stable. Any movement in the floor may crack tile, grouting, and may pinch the tanking which will affect the integrity of the system. This is particularly relevant in upper floors. you should also ensure in upper floors that the joists can take the increased weight of the tiles.
For a wet room to be sufficiently waterproof it must be tanked. This means laying a waterproof membrane on the subfloor (before underfloor heating, screed, tiling etc) and usually part of the way up the walls too. This waterproof barrier is a belt and braces approach to any egress of water, in effect replacing what we would view as the traditional shower cubicle ‘unit’ in terms of waterproofing.
Tiles. PLEASE note that if you are choosing floor tiles for your wet room floor, ensure that you check the slip resistance with your supplier. You want a tile that does not become slippery when it is wet. Large tiles will need to be cut to follow the gradient of the slope to the gulley but this can be done in an attractive way, if thought through beforehand. Smaller tiles (mosaics) can deal with this gradient more easily but you will end up with a LOT of grout to clean (this is my pet hate with mosaics)…
If you are going to all the trouble of installing a wet room, follow the uncluttered touch through into other areas of the room. Use glass as the shower screen to keep the airy feel, underfloor heating to avoid the need for a radiator, wall hung cabinetry and sanitary ware and of course, the right tiles for your overall style.
As with the majority of building projects, the success comes down to the attention to technical detail, and level of workmanship. Ensure you see previous work from your builder (and some time on, not just a few weeks when the cracks aren’t showing yet!) and ask for their recommendations on the behind-the-scenes products. They will have done this many times before (I hope) and will know the pitfalls or benefits of using certain models or styles.
Do not chose the drainage or watertightness of your wet room as a place to save money. You get what you pay for in this and it is worth buying once and buying right.
The alternative? Digging all those lovely tiles up to fix a leak, and starting again. No thank you!
Photo credit for first image: Eklund Stockholm New York. Architect: Oscar Properties.