This simple guide will detail some instructions and advice on how to prepare common surfaces before and for the installation of tiles. The surfaces that this quick guide will cover include:

• Painted Walls
• Plastered Walls
• Existing Tiles
• Concrete Floors

Painted Walls

As a general rule there is no problem with tiling over painted walls as long as the painted work is in good condition. If the paint on the wall is flaking or peeling off then you will need to look at removing the paint. 

To check the quality of the painted work, grab a length of duct tape/gaffer tape and place this strip on the painted wall. Leave to set for around 2 minutes. After this time, peel the strip of duct tape off the painted wall to see whether any paint has come along for the ride.

​If some of the paint has been removed by the duct tape then you will need to begin the process of scoring the wall to remove all of the damaged paint. To remove flaking or damaged paintwork use a knife to score the paint and a scraper to flake off as much as you can. This is done to avoid any primer or adhesive work falling off the wall because of the loose or damaged paint. 

Plastered Walls

All tiling work installed on a plastered wall should be done at least 14 days after the plaster has been installed. This is to ensure that the wall is completely dry and ready for tile installation. 

If you are planning on tiling on an existing plastered wall that is relatively old then you will need to inspect its quality and durability. This can be done by tapping on the plastered wall with a rubber mallet to check for any hollow noises in any of the areas of the wall. If any hollow noises exist then you will need to consider re-plastering or using a hardiebacker board. 

Existing Tiles - Tile on Top of Tile

When tiling on top of existing floor or wall tiles there are a few things to consider. The most important factor is the condition of the existing tiles. Check for any cracks in the tiles or joints to ensure that there is no issues with the underlying substrate or the tiles themselves. If there are cracks this means that there is movement in the existing floor tiles and they should most likely be removed. 

You will also need to check if any of the existing tiles are loose. If you have loose tiles then you will need to remove them before installing anything on top. To check if you have loose tiles, simply tap on any of the tiles using a rubber mallet and listen for hollow noises. 

​It is also important to check the height of all existing doors, skirting and other fixtures in the area you are planning on tiling. Make sure that there is an allowance for the installation of your new tiles. Most tiles will add an extra 15mm (tile and adhesive) of height to your floor. 

If the existing floor or wall tiles are in good condition then you can prepare the tiles for the installation of new tiles. First you will need to make sure that the existing tiles are clean and free of grease, grime, dirt or any scum. Tiles can be cleaned using a mixture of hot water and vinegar or specific tile cleaning products available from your local tile store.

For better adhesion to the existing tiles the existing grout should also be removed. You can remove the grout using a stanley knife or grout remover tool. Simply chip away at the existing grout until it flakes out. This will create grabbing points for the adhesive you will use for the new tiles. 

It is also important to select an appropriate primer. Primers enhance the bond between substrates and can also act as a sealing agent. Once these checks and steps are complete you can install your new tiles. 

Concrete Floors

Preparing concrete floors for the installation of tiles is one of the most common and easiest substrates to prepare. 

The first thing you need to do is prime the concrete floor using an appropriate primer. Primer will increase the bond between the concrete floor and the adhesive. Primers also reduce the amount of dust on the floor and can act as a waterproofing sealer. Primers generally take around 30-40 minutes to dry so leave it for at least this long before conducting any further work. 

The next step is to check whether the concrete floor has an even surface. This can be done by simply holding a baton or leveler around the floor. You are looking for any elevation/gaps that are greater than 3mm. If there are gaps between the baton and the floor greater than 3mm you will need to self level the floor.

To self level a floor you will need to use a leveling compound. Make sure you follow the instructions on the leveling compound packaging carefully to check for instructions and any precautions that should be take.  

When doing any tiling work start at the farthermost point in the room and make your way towards the door. This will make sure you do not walk over the work you have completely and can still get out after finishing your work.