Description Limestone tiles are a truly natural flooring option and are formed as a sedimentary rock composed mainly of Calcite (CaCo3) that constitutes about 10% of the the sedimentary rock exposed on the Earths surface. Limestone tiles are formed by crystalisation of water or by the accumulation of shell and shell fragments. Limestone tiles are usually light coloured however with impurities such as iron oxides and organic materials they can take on a variety of colours and surface markings. Limestone has been used as a building material for many generations and is gaining popularity as a sophisticated flooring material offering the timeless qualities only possible with natural materials.

Suitability There are numerous stone flooring types. They are the most thermally conductive of all floor coverings so energy from the heating pipe array can transfer quickly to the surface of the stone. Increasing the thickness of the stone will have little effect on power output, but will slightly increase heat-up times. Of all stone floor coverings, limestone requires the most care and attention during installation. In all cases, a quality 2 part flexible adhesive such as BAL Fastflex should be used. When laid on screed floor heating, a de-coupling membrane such as Schluter Ditra should be used. This prevents contraction cracks in the screed being transmitted through the floor covering.

If Limestone is to be fitted on to a floating floor, it is important that the underlying substrate is flat and level to at least SR2 standard (5mm deviation over 3 metres) so that deflection is minimised. Installing the floor heating over a flat level surface using insulation material with high compressive strength is essential. Special substrates such as Knauf Brio are beneficial for tiling on floating floors but manufacturer’s guidance should be followed.