FIXING STONE TO FLOORS

Solid floor substrates

Generally speaking, the best floor surface to fix stone to is a sand and cement screed. Please check with your builder that the screed is definitely sand and cement and not an anhydrous screed. Anhydrous screeds require special preparation – please contact the Technical Helpline for further information.

General preparation

If the screed is old or uneven then a certain level of preparation will be needed – please contact the Technical Helpline for further information.

Underfloor heating

Underfloor heating works very well with stone and is highly recommended to provide that additional level of comfort. Underfloor heating for solid floor substrates comes in two key forms: a heated screed, in which hot water pipes or electrical cables are buried; and under-tile heating, in which an electric mat or loose cables are laid over the top of the screed just under the tiles.

If your screed is heated, then you must use a proprietary decoupling membrane between the screed and the stone – heated screeds expand and contract as the screed heats up and cools down and this lateral movement will eventually cause the stone to crack if a decoupling membrane is not used.

Non solid floor substrates

Stone can be installed to most non solid substrates – but careful preparation is needed. Please contact the Technical Helpline for assistance.

FIXING STONE TO WALLS

When fixing stone to walls, it is a good idea to select a thinner stone. Also a smaller format will be simpler to fit – particularly on uneven walls. Some circumstances may require a mechanical fixing system to be used as well as the normal stone adhesive.

Solid wall substrates

The best solid wall substrate to fix stone to is a sand and cement render. Your builder will be able to confirm what the substrate is. Plastered walls will need scoring and priming before fixing stone.

Non solid wall substrates

The best non solid wall substrate to fix to is a proprietary tile backer board, which is specifically designed to receive tiles. Generally speaking a plasterboard wall is not strong enough to support the weight of stone, and plywood is not stable enough to receive stone.

This guidance is provided as an initial indication of factors you need to consider. You should also seek the advice of a professional tiler/installer who can give you advice based on the specific conditions on site. All substrates should be prepared in accordance with the relevant British Standard.