How To Install Mosaic Tiles –
An Expert Guide
Mosaic tiles are a popular choice of floor, wall and countertop covering in
bathrooms. They're a brilliant way to add texture or visual interest to a space, and mosaics with intricate patterns can create a luxurious finish to a room. Plus, there's a huge variety of shapes, colour combinations and materials to choose from, including porcelain, glass and stone.
Traditional mosaics were created by applying lots of small, individual tiles to a surface to create intricate patterns. This process was incredibly time-consuming and required a great deal of skill, which made
mosaic tiling in the past an expensive feature.
Thanks to developments in tile manufacturing, modern mosaics can be created from sheets of small tiles that are attached together with a mesh backing. This makes the application significantly faster and easy enough for amateur DIY enthusiasts to do themselves.
In this guide, we'll walk you through the process of installing mosaic tiles from start to finish to help you achieve a fantastic result for your project.
What Tools & Equipment Do I Need To Install Mosaic Tiles?
Much of the equipment used for installing mosaic tiles are common items designed for a variety of DIY projects. You'll need:
Pencil or chalk
Utility knife or scissors
Tile spacers (optional)
Wet saw, tile cutter or tile nibbler
Rubber grout float
What Materials Do I Need To Install Mosaic Tiles?
The following materials are essential for installing mosaic tiles:
Mosaic tile sheets
Notes On Choosing A Tile Adhesive
The type of adhesive and grout you choose for your mosaic project depends on the type of tiles you're using and the surface you're applying them to. Always read the label of adhesives carefully to ensure they're suitable for your project.
Ready-mixed adhesive comes in tubs and is a great way to save time since you don't have to mix it yourself. However, it's not suitable for use on natural stone or porcelain mosaic tiles because it doesn't provide enough grip. It is also not usually recommended to fix tiles to floors.
Rapid set cement is a common type of adhesive that is supplied as a powder and mixed with water. It requires a mechanical mixer to achieve the correct texture and form. It should be thick enough that it doesn't immediately fall off the trowel when you scoop it up. Mixing takes around 20 minutes and the cement cures in two or three hours. This adhesive is best suited to ceramic tiles and solid walls or cement floors.
Rapid set flex adhesive contains latex which makes it slightly flexible. This makes it suitable for wooden surfaces and floors which are subject to expansion and contraction. It's also suitable for porcelain and natural stone tiles because it offers a better grip.
6 Steps To Installing Mosaic Tiles
Taking time to carefully prep your surface and plan your layout is vital for achieving a smart finish. Once you have decided on the tile layout pattern that you want to use, you are ready to get started. Read the steps carefully and take your time in the application process.
Prepare Your Surface
Your surface needs to be as level and smooth as possible to ensure the mosaic tiles create an even finish and don't risk slipping during installation or cracking further down the line. This is particularly important when installing floor mosaics since the weight of people standing on the tiles will easily lead to cracks if the tiles are laid on an uneven surface.
If applying on a wooden floor, it's best to cover floorboards with thin sheets of MDF first. Make sure any nails or screws are properly hammered or screwed down and not protruding from the surface. With walls, remove any old wallpaper, loose plaster, nails, screws or other fixings. Fill in any large cracks or gaps in the wall with filler and make sure this is sanded down once dried to achieve a level surface.
Your surface also needs to be as clean and dry as possible before laying any tile. Dust or debris can prevent the adhesive from gripping properly. Run a vacuum over the surface then wipe it down with a damp cloth. Let it completely dry before moving on to the next step.
Depending on the quality of the surface, and the area you will be tiling, you may want to install cement board or backer board first. If you’re installing mosaics in a shower, bathroom or area that’s likely to get wet often, a waterproof backing board is recommended as a way to create an insulated and waterproof installation.
Plan The Layout Of Tiles
It's tempting to start tiling from one edge of your surface inwards, but this can lead to an asymmetrical layout and messy edges. Instead, aim to get full sheets of tiles in the centre of your surface first and work outwards, leaving the edges until last. To do this you have to measure and mark out the surface using a tape measure and pencil.
Find the very middle of the surface first and mark it with a cross. Then draw two lines, one horizontally and one vertically, from this point, using a spirit level to make sure they're straight. You now have four quadrants in which to place your first four full tile sheets in the centre of the surface. You can then mark up the entire wall with intersecting lines at intervals that match the length and height of the tile sheets.
Although not entirely necessary, if you have a laser level then this is a useful way to ensure that you have straight visible lines to work from and to tile up to. It also recommended to check you levels as you work, ensuring that each sheet is aligned correctly.
In some situations, you may choose to lay tiles differently, particularly if the tiles aren't set to cover an entire surface, such as when creating a kitchen backsplash. In this instance, it is often better to start from the highest point of the backsplash and work down so you have a nice smooth finish at the top with the cut edges hidden against the worktop.
Adhere The Full Tile Sheets First
It's easiest to start by applying full tile sheets and leaving cutting around edges until last. Apply a modest amount of adhesive to the surface using a notched trowel. You should still be able to see the surface at the bottom of the grooves created by the trowel notches. Aim for an even and level application of adhesive and work in small areas of 60cm to 80cm at a time to prevent the adhesive from drying out before you have a chance to adhere the tiles.
Apply tile sheets in line with your marked layout lines. Press the sheets down gently and hold them for a few seconds. When you release your hand, look out for the tile sliding. This is a sign that you've applied too much adhesive. You could also be using too much adhesive if lots of it oozes up between the individual tiles. Be sure to remove any excess adhesive between tiles with a narrow, sharp tool to prevent it from affecting grout application later.
When placing sheets beside one another it can be helpful to use tile spacers to make sure the gaps between sheets match the gaps between individual tiles. Choose spacers that are the same size as the gap between the individual tiles on each sheet.
As you apply your sheets you should continually check that they are level. Gently lay your spirit level over the tiles to identify any areas where some tiles or sheets are positioned higher than their neighbours. Mosaic sheets can ripple or wave since the mesh backing is flexible. To prevent this it's important to set the tiles by gently pressing them down with a flat object – a rubber grout float works well.
Cut Tile Sheets And Individual Tiles To Size
When reaching the edge of the surface and coming across any obstructions, it's necessary to cut the tile sheets. The mesh backing can easily be cut with a pair of scissors or a utility knife. If using scissors, cut from the front of the sheet. If using a utility knife, cut from the back on a firm, level and scratch-proof surface.
Avoid cutting the actual tiles as much as possible. You can often cover gaps at the edges of tiling with skirting boards, cove tiles or other accents. When it's absolutely necessary to cut tiles, you can use either a wet saw, a tile cutter or a tile nibbler. Wet saws and tile cutters are best suited for cutting full sheets of tiles. Tile nibblers, which look like pliers, are good for cutting down individual tiles.
When you cut individual tiles, first pull them off the mesh backing. Be sure to mark them up carefully with a pencil or piece of chalk. You may wish to smooth off the raw edge with a sanding pad or diamond buffer if it's very sharp or rough.
If you are tiling around a corner, or planning to finish the tiling at a mid way point on a wall, then you might need to use tile trim. This will enable you to achieve a neat, clean finish to the edges of the tiled section. Tile trim also helps to eliminate sharp edges, and is a useful way to transition from your tiled mosaic surface to another surface finish.
Grout The Tiles
Although adhesive tends to dry within a few hours, it's best to wait 24 hours before grouting to make sure the tiles are securely fixed. Grout can be purchased premixed or in powder form to be mixed with water.
Apply the grout to your rubber grout float and spread it out over the top of the mosaic tiles. Pass the float over the tiles again and again, holding it at a 45-degree angle, to force the grout into the gaps between tiles.
Grouting can be time-consuming with mosaic tiles since there are so many joints to fill. It can be helpful to mix the grout in lots of small batches to stop it from drying out along the way. Use the edge of the float to scrape up any large amounts of excess grout.
Clean The Mosaic Surface
The label on the grout will instruct you on how long to wait before cleaning the surface of the tiles. It's important for the grout to harden slightly so that it remains in the joints, but not so much that it can't be removed from the surface. Use a damp sponge to remove grout from the mosaic surface. The sponge shouldn't be so wet that it completely saturates the surface of the tile. Rinse your sponge regularly and make several passes until the surface of the tiles are completely clean.
Although it isn't essential to seal tile grout, sealing can be very helpful if you're installing mosaics in areas that are likely to get wet or dirty. Grout is a porous material and can easily stain and absorb water. If your mosaic tile is installed around a bath, shower or sink area, a sealant is highly recommended.
Grout sealants are available in spray bottles to make application easy. Simply spritz onto the tiles, rub into the grouting and use a clean cloth to remove excess from the tile surface. Once the sealant has fully absorbed, apply a second coat and wait 48 hours before exposing the tiles to any moisture. Reapply every one or two years to maintain protection.
Similarly, if you’re using glass mosaic tiles then the surface will be water resistant and easy to maintain. However, for more porous materials such as natural stone, it is recommended to seal the tiles with a suitable tile sealant once they are installed to prevent staining – particularly if they are to be used near water in bathrooms or kitchens.