How To Half-Tile A Bathroom
If your bathroom is fully-tiled from floor to ceiling, as long as they are securely fixed to the walls, it is possible to tile over them rather than go to the trouble of removing them and starting from scratch. Here, we describe how to tile over the bottom half of the walls and plaster the top half.
Begin by deciding how far up the wall your want to have tiles, and using a spirit level to mark a guideline on the wall. You can then fix a wooden dado rail or molding to act as your dividing line. You’ll need to use a tile drill bit to make pilot holes, then use concrete anchor screws for a solid wall or standard screws and wall plugs for a hollow wall. Alternatively, you could use adhesive to fix a plastic trim to the wall and butt the new tiles up to it, or use border tiles.
Before plastering over the tiles above the dado rail, you will have to clean them, leave them to dry, then sand them. Make up a mixture of 50:50 PVA and water and apply this shortly before you want to plaster, so that the surface becomes tacky. Mix up some multi-finish plaster to a smooth consistency, and use a plastering trowel to apply it to the tiles, using wide and sweeping strokes. Try to make it as smooth as you can. Once you’ve covered the entire area of wall, and the plaster has begun to dry slightly but is still wet to the touch, use a damp sponge or plant mister in conjunction with your trowel to polish the plaster and get a perfect finish. Bear in mind that the plaster will take longer to dry than if it had been applied to plasterboard and you should wait for it to dry completely before decorating it.
Work out how you’re going to position your new bathroom tiles, so that their joints don’t match up to the joints of the old tiles. As a rule, having a row of whole tiles at the top will look better, using cut tiles to fill in the gap at the bottom. So, you’ll need to measure to work out where to begin your first row, leaving the right sized gap above the skirting board so you can finish with a row of full tiles. Screw on a wooden batten to act as a support for your first row of tiles.
Treat the old tiles as you would a plastered wall, and apply tile adhesive over them in the usual way. Position your new tiles and separate them with spacers, as you normally would. Once you’ve completed your top row, which meets the dado rail, leave the tiles to dry. This will take longer than usual, so allow a couple of days to be sure. You can then remove the wooden batten and tile the bottom row with cut tiles. Again, wait for the adhesive to dry before grouting in the usual way.