While your favourite type of flooring is a matter of personal choice, slate tiles would have to be near the top of the list, right?

Slate is a beautiful and hard wearing natural stone product, which makes it ideal for flooring anywhere from a small entrance to a hotel foyer. Slate is a metamorphic rock consisting primarily of quartz, chlorite, mica and calcite.

Because it is quarried direct from the source and then merely cut to size, slate retains its unique characteristics, colour variations and texture. All of these special qualities and more are what make slate such an appealing choice for designers and architects.

In addition to its aesthetic qualities, slate tiles are naturally slip resistant, non-combustible, and impermeable to water, the colours won’t fade over time, slate isn’t affected by extremes of temperature and it is impervious to chemicals. 

With so many qualities going for it, it’s hardly surprising that slate is increasing in popularity as more homeowners discover these distinct properties and the latest extensive array of colour variations.

But it is the very qualities that make slate tiles so unique that also lead to problems if left in the hands of amateurs. 

So let’s look at the points you have to take into consideration when laying slate tiles so you can have a floor you’ll be proud to display.

  • Slate floor tiles need to be laid on a solid surface that is clean and rigid. Slate is a very inflexible material, so damage can occur if there is any movement. For more information about how to lay the correct substrate, consult a professional.Once your substrate is constructed, clean the surface thoroughly. Remove all dirt particles, old adhesive, sealers, grease or paint.
  • If the floor you want to tile has more than a 3mm fall, thickset adhesives need to be used. 
  • Slate tiles naturally vary in thickness by up to 5mm, so you will need to make allowances in the amount of adhesive and grout applied to obtain a flat surface. Your installer can give you advice on how thick the adhesive needs to be and the correct type of adhesive to use.
  • Because of the variations in thickness and also the variety of colours in each tile, it makes good sense to remove all slate tiles from the pallets and complete a ‘dry run’. 
  • Depending on the look you want to achieve, move the tiles around during the ‘dry run’ until the tonal variations suit you. Aim to lay the thickest tiles towards the centre of the area you are tiling with the thinner tiles towards the edges. The thickest tiles will dictate the overall height, while the thinner tiles will need to be built up with extra adhesive. 
  • If the slate needs to be cut, select the thinnest tiles and use an angle grinder or electric saw with a masonry disc.
  • Slate tiles often have flaky or loose layers which need to be removed with a paint scraper prior to laying. Ensure you remove excess layers before you begin your ‘dry run’ as the thickness may alter.
  • Because slate floor tiles vary in size, a space of between 6mm and 10mm is required between tiles. Although a spacer is generally recommended to create a uniform look, this can be difficult with slate.
  • Once the grouting has been allowed to set and harden for at least 24 hours, the tiles need to be thoroughly cleaned with a high pressure water jet. Allow the tiles to dry and inspect the total look before proceeding to the final stage.
  • To preserve the natural look and appeal of slate floor tiles, a penetrating sealant is recommended. This type of sealant forms an invisible barrier beneath the surface of the tile, which repels contaminants and enables internal moisture to escape. A penetrating sealant preserves the natural colour and sheen of slate tiles and makes them a breeze to keep clean. 

Alternatively, to enhance the natural colour of the slate, a water based surface sealer is an option in either a low sheen or gloss finish.

As long as you take care with the preparation and installation of slate tiles, you will have a beautiful floor that will continue to surprise and delight you 20 years from now.