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Home Installation Guide – Internal – Porcelain

Installation Guide – Internal - Porcelain

A good installation is the very foundation of a good floor. If a tile is installed correctly – and then maintained in the correct way – it will provide a durable, practical and stylish surface for many, many years to come. In this Guide, you will find general information on installing porcelain tiles indoors. We recommend that you run through this before planning your installation. If you need any more information about the installation process – or advice on which products to use to install or maintain your tiles – our expert team at Indigenous is on hand to help you.

Different substrates & preparation

There are many different types of substrates onto which tiles can be installed. For information, please see Installation Guide – Substrates.

It is essential that the substrate is correctly prepared before tiles are installed. The subfloor should be level, dry and clean. Any minor irregularities, e.g. 2-3mm over a 2m area, will generally disappear once the adhesive has been applied. A levelling compound can be used for larger holes and bumps. Any damp issues should be rectified before installation; it may be necessary to install a damp-proof membrane.

We recommend use of an uncoupling membrane which allows for any movement in the subfloor and promotes bonding of the adhesive. This will reduce the risk of tiles cracking as the result of movement in the screed.

Note! Your finished floor will be raised by the thickness of the tile, plus approx. 5mm for the adhesive and any uncoupling membrane/matting used. Some doors may need trimming and timber threshold strips may be needed to rectify different levels between rooms.

Before installation starts

As tiles are often packed quite tightly within pallets, they should be removed carefully. If any tiles have minor cracks or chips, set them aside; these tiles can be cut when smaller sections are needed. If you have any issues with damaged tiles, please let us know straight away.

Tiles should be shuffled before installation, to allow for any variations within batches and from one pallet to another.

Top Tip! Carefully consider the direction of the installation and the visual aspect of the room, as this will play a huge role in the finished look. Generally, tiles should be laid in the same direction as the main light source and towards the main entrance; this will elongate the space. Flow between rooms is also important; changing direction can create a barrier.

A note about expansion joints

When laying out the tiles, a 5mm expansion joint should always be left around the edge of the room. This will allow the floor to expand and contract naturally and will prevent the tiles from cracking. If there is an expansion joint in the subfloor, this should be carried through to the surface and should not be covered by the tiles. It’s generally recommended that expansion joints are included every 8 linear metres of running tiles and wherever there are two different screeds which meet, i.e. between rooms.

Underfloor heating

If you are installing tiles over an underfloor heating system, always follow the instructions provided by the heating supplier. Generally, the heating should be switched on and operable at normal capacity for at least three weeks before installation. The system will then need to be switched off at least 48 hours before installation and, on the day of installation, the subfloor shouldn’t exceed a temperature of 18°C. It can be switched on again one week after installation, initially at a very low temperature and increasing by 1°C per day. Make sure that the floor temperature does not exceed 27°C. To ensure this, the system should have a sensor and suitable cut off capability.

Installing the wood floor

Before installation, decoupling matting should be laid out and glued to the floor using a thin bed of adhesive. Tiles can then be fixed to the floor, using the correct adhesive.

1. Using a square notched adhesive trowel, spread the adhesive over a small floor area – about one square metre – to a depth of between 3-8mm in thickness. This should be sufficient to account for and even out varying height levels of tiles. Any deep lugs or keys on the back of the tiles should also be filled with adhesive before the tiles are fixed.

2. Using a small twisting motion, firmly bed the tile into the adhesive on the subfloor. Make sure that there are no air pockets under the tile. Fix tiles one-by-one, leaving a gap for the grout joint.

3. Use a spirit level to ensure that tiles are level. Carefully remove any adhesive that comes into contact with the tile face with a grout sponge.

4. Cut tiles to complete the installation using an angle grinder, or a water-cooled diamond cutter.

Grouting the tiles

Grout colour is a very personal choice and it’s worth testing on a small, inconspicuous area first, to ensure a good colour match to the tile. The size of the grout joint is also an individual choice and can influence the overall look of the floor. Before grouting tiles, make sure that the adhesive is completely dry.

1. Make the grout into a slurry and apply it to 1m2 areas at a time, using a squeegee.

2. Remove surplus grout and clean the grouted tiles using a wet grout sponge. Be careful not to spread the grout around too much.

3. When all of the tiles have been grouted, clean the floor thoroughly again using the correct cleaner.

4. Once the grout has dried, sweep the floor to remove any remaining dust and residue.

Sealing grout joints

Our porcelain tiles do not need to be sealed. However, we recommend application of a grout joint sealer, eg., LTP Grout & Tile Protector. For advice on ongoing maintenance, please see our Floor Maintenance Guide.