Installing bathroom floor tiles is a wonderful way to make a statement which reflects your individual tastes. Although tiling a bathroom has traditionally been thought of as a complex DIY task, it’s perfectly possible to achieve a professional finish with thorough planning and by carefully working your way through the steps we provide in this guide.
Bathroom tiles are durable and easy to clean, meaning that in the long term they’re very cost effective to install. Other than regular cleaning and occasional replacement of sealant or grout, bathroom tiles are also low maintenance.
In this guide, we’ll take you through the whole process of fitting bathroom tiles, from planning, to cutting and laying tiles, and finishing off with sealant and grouting.
What do I need to consider for my floor tiling project?
Thorough preparation is crucial if you want your tiles to be laid properly and last a long time. Before you start laying tiles your floor needs to be solid, level, clean and dry.
If you’re thinking about tiling over existing floor coverings – the general rule is don’t! Durable tiling relies on perfect adhesion to the floor. Your new tile floor may be secure, but the old floor beneath probably won’t be, and this will only lead to long-term issues.
Some existing surfaces, such as a level concrete floor, don’t require a sub-floor, and you can lay tiles straight on top as long as the surface is level and completely clean and free from old adhesive.
The surface you are laying tiles onto will determine the type of tile adhesive you use. Usually a flexible tile adhesive is suitable, but a strong high-bond adhesive is best for concrete floors. Be sure to check the manufacturer’s instructions first.
To establish how many packs of tiles you will need, calculate your surface area in m2 (length x width), and check against the coverage of the pack. Add at least 10% for inevitable wastage and offcuts.
Tiles are usually given batch numbers, so to ensure proper colour matching try to buy all your required tiles from the same batch.
Where do I start when tiling a bathroom floor?
Finding the right starting position is crucial when laying your bathroom tiles, as it determines whether the finished floor looks right. The object of planning your layout is to create a ‘central’ area to lay down whole tiles then to lay edge tiles around this area. When you’re laying your tiles you want to be able to exit the room without walking across newly laid tiles. It’s best to work from the central areas to each corner, then finally work towards the door.
Preparing your bathroom floor for tiling
Step 1: prepare the tile backer boards
You’ll need to install tile backer boards that are suitable for use in wet and humid areas onto your wall before you start tiling. New changes to British standards don’t allow tiles to be installed directly onto plywood, and these provide a safer, water-resistant alternative that is designed for hard-wearing areas such as flooring.
Start by laying your tile backer boards on the floor, making sure the entire area is covered and cutting your panels to size as needed.
Step 2: secure the tile backer baords
Use a plasterboard-friendly sealant along the edges of your backer boards to hold them together on the floor as well as against any walls and other vertical surfaces.
Screw them into the floor with a drill and specialised corrosion-protected screws, such as stainless steel.
Step 3: seal the floor
Brush the floor to remove any debris that resulted from drilling your backer boards.
Then seal your floor using a primer to reduce porosity levels before you start tiling.
Step-by-step guide
Step 1: planning the tile layout
During this planning stage, it’s very helpful to ‘dry lay’ your tiles down so you know what the final layout will be. To find your starting position, measure the width of your room and mark the centre point on the floor with a pencil.
Then from this centre point, position the tiles going towards one of the side walls, inserting tile spacers between each tile.
Because a thinner edge will look untidy once laid, it’s important to ensure your edge tile is at least half the width of a whole tile. When dry laying your tiles, if the gap between the last whole tile and the wall is in fact less than half the width of a whole tile, then move all your tiles and spacers away from the wall by half a tile’s width. This ensures a larger and better-looking edge tile.
Once the gap is more than half a tile’s width, mark the position of the last whole tile on the floor. This will be a starting mark for the fitting line.
Measure the distance from this first fitting mark back to the centre of the room and note it down. You will need this measurement to determine the fitting line along the whole length of the room.
Move further down the room and find the midpoint of the room again. Use the measurement you noted down to mark on the floor the next position of the fitting line. Repeat this process as many times as necessary until you’re confident you have a straight-fitting line that runs the length of the room.
Step 2: cutting your tiles
For your edge tiles, you may need to cut your tiles to size. Measure the width between the fitting line and the wall, then transfer these measurements onto your tiles, making sure you’re subtracting the gaps between the tiles.
Then trim them down with a single straight cut, using a manual tile cutter.
Step 3: preparing the adhesive
When preparing your adhesive, check the manufacturer’s instructions for the ideal water-to-product ratio.
Then use a drill and whisk to mix the adhesive with water until you get a consistency that’s thick enough to hold its shape on the trowel, but still malleable enough to spread easily.
When you’re done, clean the whisk in a bucket of clean water to prevent the adhesive from building up.
Apply the adhesive to the floor using the notched side of your spreader. Straight, uniform lines help to avoid creating air bubbles, so you get a stronger bond.
Then you’ll need to ‘backbutter’ the tile, which means using the straight side of the spreader to cover the surface in adhesive. Apply a smooth layer and scrape any excess adhesive back into the bucket.
Step 4: laying your tiles
Place the tile onto the floor in line with your measurements, pushing down on all sides.
Put spacers in the gaps to make sure everything is evenly spaced.
Use a spirit level to ensure the tiles are level. Continue this method for the entire floor, working towards the corners before finishing by the door.
If necessary to ensure all tiles are flush against your wall, use a handheld circular saw to cut into the bottom of your door frames, architrave, skirting boards and other decorative mouldings, using the depth of your tiles as a measurement guide.
Check your adhesive’s packaging to find out how long it needs to set. Once set, remove the spacers.
Step 5: grout the tiles
Mix your grout with clean water according to the instructions on the packaging. Then mix with a drill and whisk until you get the perfect consistency. It should be thick enough to hold its shape on the trowel, but still malleable enough to fill the grooves between your tiles.
Starting at the centre of the floor and finishing by the door, place the grout over the joins and gently work it into the gaps with a grout float, making sure it’s flush with the tiles.
Leave it to partially dry and wipe off any excess with a damp sponge. Be careful not to apply too much pressure at this stage so you don’t pull any grout out of the floor. It’s also a good idea to wipe across the joins rather than along them for the same reason.
And there you have it - a newly tiled bathroom floor. You can then continue to tile the rest of your bathroom if you're refreshing your walls and bath panel.
