As a natural material, natural stone has actually been used for building since the Roman times.
Natural stone comes in a variety of colours, textures and patterns, which enables versatile design styles. Due to the mineral composition, natural stone is highly durable, and can be far more resistant to abrasion and chemicals than tile and agglomerated stone.
The Tile Association advises on a few key points for a successful design and installation using natural stone.
The choice of the right stone
It’s important to ensure the stone has adequate properties for the intended use. CE certificates will provide helpful technical data. Other test data conforming to the British Standards may also need to be referenced.
The safety factor needs extra attention. As a natural material, some stones can weaken over time or form micro-cracks due to weathering; some may contain unseen flaws which may have not been presented in the test samples.
The required thickness also needs careful calculation.
Light coloured and/or absorbent stone is very susceptible to staining and discolouring by bedding and jointing material. Curling and movement can be a problem with an absorbent stone. When only one side of the stone absorbs water , i.e. from the adhesive or grout, and expands, a curve will form. This movement of the stone can weaken or disrupt the bonding of the adhesive underneath.
The choice of a fast-setting, flexible, cement-based white adhesive and a light-coloured grout with such properties can negate the risk of staining and curling. Stone should be fixed in solid bed method. A protective sealer may be required before grouting. For calcium carbonate-based natural stone such as travertine, marble or limestone, choose a neutral curing sealant. Sealing and a regular cleaning regime can help maintain a lasting beautiful surface in use.