Tongue and groove has been used in bathrooms for a very long time, and it still looks right in them. It gives a cottage bathroom its character and makes a plain modern one feel warmer. The catch is that bathrooms are hard on timber, and boards that are fine in a hallway can swell, stain or open up once they meet steam every morning.
This guide is only about the bathroom. We have a separate guide on tongue and groove generally and one on panelling in bathrooms of every kind; here we focus on what changes when the boards are vertical, jointed and close to water.
Where it belongs and where it does not
The safe zones are the walls that get steam but not spray: behind a basin at a sensible height, around a toilet, on the wall beside a bath outside the splash area, and as a half height boarding around the room. Inside a shower enclosure, or anywhere water runs down the face of the wall, tiles or a proper wet wall system are the better choice.
A common and handsome layout is boarding to around dado height around the room with tiles where the water actually lands. The boards give the room its look, the tiles do the hard work.
Why the joints matter more than the boards
Tongue and groove is made of many narrow boards, and each joint is a place where moisture can get in. Timber moves as it takes on and loses moisture, so in a humid room the boards swell in the morning and shrink back later. Over months that movement can crack paint along the joints or leave dark lines where water has been drawn in.
The answer is to seal every face, including the tongues, edges and backs, before the boards go up. Painting only the front face after fitting leaves the hidden parts unprotected, and that is where most trouble starts.
Choosing the material
Moisture resistant MDF boarding is stable and takes paint beautifully, which is why we use it often for painted finishes. Solid timber boards have real grain and character but move more, so they need allowing for. Whichever is chosen, the bottom edge near the floor and any cut ends around pipes should be sealed with particular care, because that is where water sits.
Paint and finish
A good primer followed by a hard wearing paint suited to bathrooms makes a big difference. Satin and eggshell finishes wipe clean more easily than flat matt. Dark colours look striking in a bathroom but show water marks and limescale splashes more readily, so they suit a cloakroom better than a family bathroom with a busy shower.
- Seal every face of each board before fitting.
- Leave a small gap at the bottom and seal the cut edge.
- Use a cap or dado rail to finish the top edge cleanly.
- Keep a flexible seal where boarding meets a bath or basin.
Ventilation and pipes
No finish survives a bathroom that never dries out. A working extractor fan, run long enough after a shower, does more for panelling than any paint. Where boarding runs over pipework, a removable section or access panel saves pulling the whole wall off if a valve needs attention later, and we plan those in from the start.
Fixing it to the wall
Boards are usually fixed to battens so there is a little air behind them, which helps the wall and the boards dry. The battens also let us get the boarding plumb when the wall behind is not. Starting straight in the first corner matters, because a small lean in the first board becomes an obvious one by the far wall.
Done this way, tongue and groove in a bathroom can look good for many years. When we come to see the room we look at where water goes, how the room is ventilated and what finish you want, then recommend where boarding and tiling should meet.
Common questions
- Can you put tongue and groove in a bathroom?
- Yes, on walls that get steam rather than direct water. Around a basin, a toilet and outside the splash area of a bath all suit boarding well.
- Can tongue and groove go in a shower?
- We would not recommend it inside a shower enclosure. Tiles or a proper wet wall system handle running water far better.
- How do you stop tongue and groove swelling in a bathroom?
- Seal every face of every board, including the tongues and backs, before fitting, keep the bottom edge off the floor and make sure the room is well ventilated.
- Is MDF tongue and groove suitable for a bathroom?
- Moisture resistant MDF boarding is a good choice for a painted finish, as long as all faces and cut edges are sealed and it is kept out of direct water.
- What paint finish should I use on bathroom panelling?
- A satin or eggshell paint suited to bathrooms, over a proper primer, wipes clean more easily than a flat matt finish.
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