Natural Stone Fixing Guide

Natural Stone Fixing Guide


This guide is not intended to be a definitive guide to fixing natural stone tiles. If you are uncertain about anything having read this guide, you should consult a professional tile installer who is experienced with the installation of stone tiles.

It is the responsibility of the purchaser/installer to adhere to the following guidelines and install them in accordance with the current British Standards Institute Standards of Installing Wall and Floor Tiles and Mosaics: BS 5385



Natural Stone tiles are available in a wide range of types, sizes and finishes, with a design to suit every taste and every home. 

Using this guide will help you to: 

• Choose a suitable product for your project 

• Calculate how many tiles you require 

• Prepare and plan for the installation 

• Mark out the work area 

• Fix, grout and impregnate 

• Clean and maintain your finished installation 


Selecting your natural stone tiles and stone mosaics

This is the most important and enjoyable task. With such a large range of tiles to choose from, you may like to order some samples to see how they fit in with the rest of your furnishings and decorations.

Tiles differ in size and thickness and choosing the right size is just as important as choosing which type. Small tiles are often better suited to covering small areas, whereas larger areas look better with larger tiles.

Suitability of your chosen tiles is also an important factor.



Suitability of your chosen tiles is an important factor. Please refer to the specification box on each product page for the suitability of each individual product

As stone is a natural product it can subject to colour variation, pitting, blemishes, chipped edges, size variation and on occasion staining. We strongly recommend that you buy all the tiles you need for your project at one time.

It can also fade in UV light. No guarantee can be made against this.

Natural stone tiles for installing externally need to be a minimum of 20mm /3/4” thick, to reduce the risk of frost damage.

Most natural stone tiles and mosaics can be used for wet walls although they are NOT suitable for installation in steam rooms or spas due to its porous nature and the harsh environment of such installations.

Polished natural stone is NOT suitable for use on the floor in wet areas due to its slippery nature. It can, however, be used for dry floors providing adequate matting is provided to remove excess water from footwear prior to walking on the tile.

Do not fix to wooden substrates. All wooden substrates should be over boarded with cementitious tile backer boards in accordance with the manufacturer’s instructions. If in doubt consult a professional before proceeding.


How many tiles will you need?

Once you have decided on your tiles, calculate how many you will need by measuring the area to be tiled. Recommended grout gaps vary depending on personal taste and the look you wish to achieve, and also the uneven nature of the tile edge. Generally, the more rustic the tile base, the wider the grout gap. 

How to calculate the square metre/square foot measurement of the area to be tiled: 

Wall: measure the height of your room or the height you will require the tiling to end and multiply by the width. 

Floor: measure the length of the area to be tiled and multiply by the width. The result will be the square metre/square foot measurement of the area to be tiled. 

If the shape of the area to be tiled is a simple square or rectangle you can simply calculate the area of each tile and divide it into the area of the floor or wall. This assumes that the area being tiled is square at the edges, if not you will need to allow some extra for part tiles. 

An alternative method is to make a scale drawing of the floor and/walls on a piece of graph paper, draw the outline of each tile (including dados, trims and borders where appropriate) and add them up. 

We recommend that you allow for part tiles, wastage and any imperfections by adding at least five per cent to the total for mosaics and ten per cent for larger tiles. It can be a false economy to only order the exact quantity. You may break some tiles when cutting or you may end up with awkward shapes that take more tiles than anticipated. It can be frustrating to get near the end of the job only to find that you are short of one or two tiles.

If you have any problems calculating the number of tiles required please do not hesitate to **contact us**


Before fixing

Please refer to product page for special notes regarding suitability, sealing, grouting, cutting and other appropriate information and warnings.

It is important that your tile installer understands any blends or patterns you want, the requirements for surface preparation and protecting newly installed tiles from on-going work. Floors and walls may require expansion joints.

Always check the tile weight is suitable for your substrate adding 3.5kg per m² /6.4lb per yd2 for adhesive and grout per m².


Conditioning/Deep Clean

All natural stone must have a conditioning or deep clean before sealing. Ensure they are thoroughly clean and dry before sealing.



Before installation, please make sure you store any fixing materials and your tiles in their packaging in a clean and dry area. All tiles must be dry before installation.

Natural stone tiles and mosaics may be wet on arrival so will need to be fully cleaned and dry. To dry, lay them out in an aerated room. Make sure they are fully clean and dry then impregnate (seal) before and after grouting. Lithofin MN Stainstop and LTP Mattstone are suitable.

Failure to dry the tiles before sealing can result in moisture being trapped behind the tiles which can react with the tiles causing them to deteriorate over a period of time.



Always lay the thickest tile first and adjust the adhesive thickness for the other natural stone tiles to achieve a perfectly level floor.


Grout Gap

For internal installations, sizes under 300x600mm the grout gap should be no less than 2mm, for 300x600mm and over, the grout gap should be 3mm or over.  For external installations, the grout gap should be at least 3mm.

Spacers that have been used during the fixing process must be removed from the joints before the adhesive setting time is reached.



We recommend a white, fast setting, highly deformable S1 or S2 TYPE adhesive which has a ‘T’ modification (this stops the tiles slipping down the wall).



Natural stone MUST be impregnated before and after installation when the tiles are fully clean and dry. Seal before grouting and then again after the grout residue has been removed. Lithofin MN Stainstop and LTP Mattstone are suitable impregnators.


Expansion & Movement Joints

Where tiles meet another surface or change plane, the joint is filled with silicone sealant, not grout, to allow for minor expansion and contraction. Movement joints should be placed over existing joints, changes of substrate, as well as around areas no greater than 40m2 and no length should be greater than 8m without a movement joint.


Special notes 

Limestone/travertine For light coloured porous stone products such as limestone and travertine use a white, fast setting highly deformable cement based C2-S2 type of adhesive. This will reduce the possibility of water staining on the surface of the tile from the adhesive during the curing process. It will also reduce colour show through on the light coloured stone tiles.


Travertine tiles have voids or pinholes that can appear after installation. No guarantee can be given against this occurring. Any voids that do appear can be filled with either grout or an epoxy resin.


Limestone needs particular care when installing on a timber substrate. The installation surface needs to be rigid and strong or the tile could be damaged or crack.


Alexandrian Sun can contain areas of iron oxide and if this comes into prolonged contact with water the iron content may expand causing delamination of the tiles surface. This stone must be completely dry before sealing and the correct amount of sealer applied following manufacturer’s guidelines.


Marble tiles inherently have a natural veining effect. As the marble is cut into the various different formats of trims, flats, bevelled edges and mosaics there will be differences in shades, tones and veining. This may be more noticeable if the flat tiles and the smaller pieces such as the smaller bevelled formats are placed next to one another. They may differ but the overall effect will be stunning.


Natural slate can suffer from delamination due to the laminar structure of the natural stone. If this happens during installation remove all the loose pieces, clean and then re-seal the affect portion.


Terracotta tiles are extremely porous and will require a lot of sealing. Newly installed tiles will be very light and can take some time to achieve a richer colour although this can be sped up with the use of modern sealers. See Sealing section, below.


Pebble mosaics may require the removal and adjustment of individual pebbles so that the sheets interlock avoiding visible grout lines. They can also suffer from iron staining, if this occurs remove the pebble affected from the sheet and replace it with one of a similar size from a spare sheet.


Mixed format borders containing metal

Some mixed format borders contain metal. Extreme caution must be taken when using metal mosaics or borders in an electric shower. Always consult a qualified electrician prior to installation. Metal pieces are prone to scratching, so use a fine or un-sanded grout on an unfixed tile to test, before grouting the whole installation.



Not all cleaners are equally suitable for all types of tiles. Wash down tiled surfaces with either clean water or a pH neutral (i.e. not acidic or alkaline) detergent. Dry off and polish with a dry duster. Certain acid based cleaning products may cause some of the tiles to react and change in character.

Do not use abrasive cleaners or cloths.


Steam Cleaning

We do not recommend steam cleaners or steam mops to clean our tiles.

Steam cleaning may remove or render ineffective any sealer that has been applied, leaving the tiles unprotected.


Underfloor Heating

Underfloor heating systems must be turned off and the floor must be cool before tile installation commences. Following tiling the heating system must not be turned on for 28 days to allow the adhesive to fully cure and then turned up at 5 degrees C per day until the maximum operating temperature is attained.



Owing to variations in studio lighting the tile colours shown on the County Tile website may differ slightly from those of the actual tiles. Before making your choice it is always advisable to order samples.


Limits of liability

County Tile accepts no liability for the faulty installation of its tiles. In the case of any claim relating to the tiles themselves, County Tile's liability, to the extent permitted by law, is limited to either the replacement of the product or a refund of the cost of the product, and does not extend to cover any consequential loss.

Claims must be reported within seven working days from receipt of the tiles.

Tiles must be inspected prior to installation and claims cannot be considered after the tiles have been installed.

Please be advised that installation constitutes acceptance of the quality, colour, texture, shade and size of tiles.

County Tile warrants that its tiles conform to their description and are fit for their purpose. County Tile makes no other express or implied warranty as to fitness or suitability of the products for particular installations.

We extend no guarantees, express or implied, as to wear resistance or maintenance procedures.

Please note, the use of certain acid based cleaning products may cause some tiles to react and change in character.

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