Tile Installation

Installation Guide

PRE-INSTALLATION

Natural stone tiles are cut into slabs using water-cooled machinery and are often packed immediately into crates once they’ve been cut. With this in mind, when you receive your delivery the tiles may still be wet or damp and appear darker in colour. We highly recommend for customers to have their tiles on site one week prior to installation for them to dry and acclimatise before laying. Once the tiles are dry, the true colours and markings are then visible – facilitating even blending of the tiles and achieving the best look possible for your floor.

If you are storing your tiles for a little while, ensure they are stored in a safe and dry location. Frost resistant stones can be stored outside but they must be covered and protected from the elements.

SUBSTRATES

Different substrates mean different fixing procedures may need to be followed. Using the wrong fixing procedure for your substrate could lead to numerous problems. All advice is given as a guideline and it is important you consult with your screed supplier to ensure the correct screed is identified, along with their recommendations prior to installation.

 

SAND & CEMENT

Sand & cement screeds are traditionally the most popular type of screed. This screed works with wet underfloor heating systems, however, as it is susceptible to cracking, we would advise using anti-fracture matting which greatly reduces the risk of cracks in the screed transferring through to the tiles. In larger areas, it is always best practice to leave expansion joints in doorways and/or edges of the room.

This screed does not need to be primed before installation although it may be recommended by your screed supplier. 

The screed must be moisture tested and fully cured prior to tile installation. Please also ensure the screed is clean and dust free.

 

ANHYDRITE (GYPSUM) 

Anhydrite screeds are usually self-levelling flow screeds. They are easier to install but take a bit longer to dry and require more preparation work before fixing tiles.

This screed works well with under floor heating, although we still recommend installing anti-fracture matting when using wet underfloor heating systems.

Anhydrite screeds have a latency layer that rises to the surface which is weak and must be ground off

Anydrite screeds are gypsum based. Most adhesives are cement based and won’t adhere to gypsum. To avoid failure of fixing there are two solutions. Solution 1 is to prime the floor with a suitable primer, such as Kerakoll Eco A Primer; two coats are required at a criss–cross to each other. Solution 2 is to use a gypsum based adhesive. Gypsum based adhesives are more expensive than cement based adhesives so usually priming is the most cost effective option.

The screed must be moisture tested and fully cured prior to tile installation.

 

WOODEN FLOORBOARDS

  • Wooden floor boards often have quite a lot of vertical movement and it is important that this is minimised. Non-stable floors can lead to cracking of the tiles/grout.
  • We’d recommend using marine plywood or tile backer boards to create a stronger, rigid substrate.
  • These are usually screwed down to your joists every 2-4 inches to minimise as much movement as possible.
  • You may or may not need to prime the substrate depending on which material has been used to reinforce the wooden floor.
  • Similarly, depending on how much vertical movement is left, you may or may not decide to add a latex additive to your flexible adhesives and grouts to allow for extra flex.
  • Anti-fracture matting is not designed to protect against vertical movements, only horizontal movements.

ADHESIVE

We recommend to always fix natural stone tiles on a full, solid bed of flexible white adhesive. We strongly advise against spot-fixing, as this can leave marks on the stone tile surface. Please consult with your professional tiler if you are not laying on to a flat surface.

To ensure an even adhesion, large format tiles may need to be back-buttered first. Only use pure white adhesive – not grey or any coloured adhesive. The reason for this is to avoid any mineral or pigmentation bleed which could cause a chemical reaction and undesirable darkening or marking of the tile.

Ensure that you clean off any adhesive that lands on the tile surface with a damp sponge as you go. A latex additive can be added to the adhesive if extra flex is required due to wooden substrates.

Levelling

A degree of variation in dimensions within Porcelain tiles is to be expected, due to their nature and production. This is often more noticeable on larger format tiles. In order to avoid emphasising this, joints should be staggered by a maximum of 20-30% of the length. It is also standard practice to use levelling wedges and spacers when tiling, in order to create a flat and level floor. Should you have any queries, please speak to one of our team or discuss with your tiler.

GROUTING

All tiles need to be grouted. For the best look, choose a grout colour the same or lighter than that of your stone tiles. If you choose a colour that is darker, you may run the risk of ‘picture framing’ – this is where the grout is absorbed by the tile, staining the perimeter of your tiles. For all natural stone tiles, we always recommend sealing the edges of the tiles when using any grout colour.

The thinnest grout joint achievable is around 3mm. Most customers opt for a 3-5mm grout joint, while a tumbled edge will naturally yield a slightly wider grout joint. Grout joints can vary slightly when fixing a pattern format with mixed tile sizes – this is perfectly normal. 

Make sure grout joints are dry and free of dirt and dust prior to grouting. Always follow the product specification sheet when installing.

It is crucial for any grout residue on the surface of the tiles to be cleaned as part of the grouting process. We recommend cleaning the floor thoroughly and allowing time to fully dry before sealing with a 2nd coat. MN Power-Clean can be used to remove any grout residue that has dried on the surface of the tile. 

SEALING

Sealing

  • All natural stone must be sealed
  • We recommend Lithofin Stain Stop MN which is an impregnating sealer sitting just below the surface of the stone. It is a matte sealant with minimum alteration to the appearance, leaving the stone looking as it was intended to after manufacturing.
  • Lithofin Stain Stop MN repels water, oil and grease.
  • Some sealants can leave an artificial sheen to the surface of the tile.
  • It is possible to use a colour intensifier in conjunction with a sealer to draw out bolder colours.
  • We recommend sealing the tiles after initial fixing.
  • Tiles must be clean and bone dry prior to sealing
  • We recommend a further seal after the grouting process which will add protection to your grout too. Again, tiles must be clean and bone dry.
  • It is important to seal the edges of the tiles prior to grouting as this helps prevent against pigmentation bleeding resulting in picture framing (a darker outline around the edge of the tile)
  • Sealant will usually last approx 4-6 years before a top-up coat is require. In high water traffic or outdoor areas this may need to be adjusted to once every 6-12 months.
  • Sealant can’t protect against acidic reactions. If any strongly acidic liquids are dropped onto the surface of the stone it is recommended to neutralise them with water and clean as soon as possible.
  • Sealant acts as a first line of defence. Eventually, if left uncleaned, the sealant can be penetrated and in worst case scenarios the stone stained. The sealant does a great job but, if you spill something like coffee onto your floor it is advised you clean it up before heading off on a weekend break!