Laying floor tiles
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.
How do I prepare a bathroom floor for tiling?
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.
In addition, natural stone bathroom tiles such as limestone, marble & slate will need sealing first. This is usually done after laying the tiles but before grouting. Most ceramic tiles and glazed porcelain tiles don’t need sealing.
How many tiles will I need?
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.
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.
Use a detector to check for hidden pipes and cables around the fitting line. If the area is clear then screw a timber batten into position along the length of the fitting line. If you are laying onto a concrete floor then mark the fitting line with a straight edge and marker pen – there is no need to fix a batten.
Now you need to repeat the above process working across the width of the room. The aim is to fix another timber batten running width-ways. The corner where the two battens meet will be where you start tiling.
How do I lay floor tiles?
If you’re mixing your own powder adhesive, then following the manufacturer’s instructions add the correct amounts of water and powder to a bucket. Use a paddle mixer to mix it thoroughly until you have a thick, lump-free paste.
From your starting point, apply tile adhesive to about 1m2 of the floor using a notched gauging trowel. Spread the adhesive on the floor using the smooth edge, then draw the trowel back across using the serrated edge. This forms ridges in the adhesive and helps to create a secure, even surface to lay the tiles on. Then press the first tile firmly in position, with a slight twisting action to help secure the adhesive.
Lay down your subsequent tiles, using tile spacers to separate them. Use a spirit level to regularly check that the tiles are flat and level. If a tile is too high or low you can gently lift it out and add or remove adhesive as required. Alternatively, lightly tap the tile with a rubber mallet to level it off.
As you go along, remove any adhesive from the tile surface with a damp sponge and clear out any excessive amounts of adhesive from the grout lines. Continue until all the tiles have been laid, then allow to dry completely before removing the battens. If you have used vertical tile spacers you will need to remove them too. Flat tile spacers can’t be removed.
How do I cut bathroom tiles?
Now you have fitted your whole tiles, you’ll need to cut and fit the edge tiles. Start by measuring the gap between each whole tile and the wall, allowing 5mm for the tile spacer. You should measure each individual tile because walls are often not straight, so don’t assume the gap is the same along the whole wall length.
There are several different methods for cutting tiles, and how you use them depends on the type of tile you have and the cut you need to make. See our guide on how to cut tiles for more details. The four main methods are:
First of all, wear safety glasses and work gloves when cutting tiles. Scribing the tile is the simplest method – using an aluminium rule and a pencil, mark your measurement onto a tile and draw a cutting line.
Firmly hold the rule against the pencil mark and use a tile scribe to score the pencil line several times. Make sure the tile is scored along its full length to guarantee a clean edge.
Place your pencil directly underneath the scored line and press down firmly on the tile to split it.
Place each cut tile into position along the wall to check that it fits properly, remembering to allow for the tile spacers. If you’re happy with the fit, then apply tile adhesive to the floor as before, and fix the cut tiles. Once the tiles are laid, leave the adhesive to dry completely before continuing.
How do I tile round an obstacle?
Bathroom furniture such as bathtubs, sink pedestals and cabinets need to be accounted for, so you’ll have to cut any tiles specifically to shape. It’s best to start this when the rest of your tile adhesive is fully dry, otherwise you risk moving already laid tiles.
The best way to do this is to create a paper template of the necessary tile shape. Cut a piece of paper to the same size as a whole tile, then cut a series of 5-10mm wide slits along the edge where the paper tile touches the base of your obstacle.
Place the paper tile into position, allowing a 5mm gap for tile spacers. Form your edge against the obstacle by pressing the paper down and folding back the slits. Then use a pencil to mark the edge of the obstacle along your template. Remove the template and cut along the edge line.
Check that your paper tile is an accurate fit, then tape it to a real tile and carefully mark the intended cut line. Remove the paper and tape and use a tile scribe to score along the pencil line.
Use a tile nipper to cut away the unwanted part of the tile. Only remove small chunks at a time as you work your way towards the scribed edge. Take much smaller chunks when you get close to the line.
When you reach the scribed line, smooth off the edges using a tile file or fine grade sandpaper. Then wipe the tile with a damp cloth to remove any dust, and fit the cut tile.
How to grout floor tiles
Once the tile adhesive is dry, make sure the tiles are free from dust and dirt, and that no tile spacers are sticking up. Mix up the grout and place a small amount onto the tiles. Use a grouting float to work the grout into the tile joints, moving swiftly with diagonal strokes.
Once you’ve grouted several rows, run a grout finishing tool along the joints to give a neat smooth finish. If any grout gets on the tiles, then wipe away with a damp sponge before it starts to harden.
Once the grout has dried, wipe down the tile surface with a clean soft cloth to remove any powdery residue. Then spray on a grout sealer. This will prolong the lifetime of the grouting by protecting it from water, dirt, grease, etc.
Finally you need to seal the edges of your new tiled floor. Place strips of masking tape around the edge of the floor and the base of the wall, then seal the joint between them using a suitable bathroom sealant. You can use a shaping tool to give the sealant a smooth finish and remove any excess.
If possible, avoid using the floor for 24 hours after grouting and sealing.
