How to Install and Grout Slate Tiles

Slate Floor Tiles
When tiling slate floor tiles or slate wall cladding, you should use tile adhesive. Using a notched trowel, glue should be put on the floor at least 5mm thick. Before putting the tile down, a thin layer of tile adhesive should be put on the back. Before tapping with a rubber mallet, you should twist the tile into the wet tile adhesive to get rid of any trapped air. The only thing you should use is a white rubber mallet. Black rubber could leave a mark on porous tiles that won’t come off.
If you don’t use traditional tile grout, it is best to use a 50/50 mix of clean yellow plaster sand and cement to fill the spaces between slate tiles. Bonding liquids should only be added to the grout if they can be cleaned up right away and in the right way. Grout must be cleaned up right away after grouting to avoid staining and marking.
You should only grout small areas at a time, and you should clean up any extra grout on the tile surface before the grout has dried. To help clean slate tiles after grouting, Stoneshield Grout-Lift™ should be added to the water. If the grout on the tile surface is dry, it can be hard to clean and may stain or damage the surface. Grout and cement residues can be removed from slate floor tiles with acid-based cleaners like Stoneshield Grout-Lift™, followed by Stoneshield Deep-clean™ to neutralise the surface after cleaning to help keep sealers from not working.
Why It’s Important to Seal Slate Tiles
Natural slate floor tiles need to be sealed. Sealers are meant to protect surfaces from stains as well as general wear and tear.
Reasons why it’s important to seal slate tiles:
- Sealing makes the tile or stone less porous, which makes it less likely that stains will stay.
- Sealing keeps acids penetrating and damaging slate tiles.
- Sealing strengthens the surface, making it more resistant to wear and tear and better able to protect itself.
- Sealing natural stone, terracotta, etc., often makes the finish look better.
Recommended Sealer Selection for Slate Floor Tiles
To correctly seal slate, using the correct products and following usage instructions to a t are equally important to successfully seal slate wall cladding or flooring. In our experience, the following products are most likely to deliver long lasting and professional looking results when sealing slate tiling:
- Stoneshield Quarri-Seal®: Stoneshield Quarri-Seal is a high-quality, solvent-based resin sealer that doesn’t turn yellow and gives surfaces a satin finish, better stain resistance, and better protection. A sealer that deeply penetrates into the wood and gives it a ‘wet look’. It can be put on concrete, cement screeds, natural slate, and other natural stones both indoors and outdoors.

Stoneshield Quarri-Seal
- Stoneshield Quarri-Seal Matt®: This is a non-gloss, non-yellowing, solvent-based resin sealer that has great stain resistance, and protects surfaces well both indoors and outdoors. The sealer provides a matt, semi ‘wet-look” finish’. Suitable for concrete, cement screeds, natural slate, and other natural stones.

Stoneshield Quarri-Seal Matt
- Stoneshield Premium Plus™: A high-quality, solvent-based, two-part polyurethane resin sealer that doesn’t turn yellow and has a high-gloss finish, great stain resistance, and protects the surface. A sealer that goes deep into the wood and gives it a ‘wet look’. Can be used inside and outside. It can be put on concrete, cement screeds, natural slate, and other similar natural stones.

Stoneshield Premium-Plus
- Stoneshield Colour-Enhancer™: Stoneshield Colour-Enhancer is a water-based penetrating water repellent that is designed to protect against rain, moisture, general airborne dirt, pollution, mould, and mildew. It has no sheen, no surface film, and allows water vapour to pass through. It can be used both inside and outside for natural slate, concrete, cement screeds, and other types of natural stone.

Stoneshield Colour-Enhancer
- Stoneshield Wall Cladding Sealer™: A water-based penetrating sealer with a natural look, no sheen, and no surface film. It is made to protect against rain, moisture, general airborne dirt, pollution, mould, and mildew. It can be used both inside and outside on concrete, bricks, slate, and other types of natural stone.

Wall-Cladding-Sealer
Be sure to carefully read instructions on how to use sealing products and ensure that the selected product is fit for purpose. All the products you need for slate sealing success (and more) can be purchased from the flooring wizards at FloorsHQ.