How do I lay rubber tiles over natural stone paving?

Rubber tiles can be laid directly over natural stone paving where the slabs are firm, level and load-bearing. Outdoors, the substrate must have sufficient fall towards a free edge or drainage outlet.

Sawn or ground slabs of granite, marble, sandstone, travertine or slate are generally suitable as a substrate. The rubber tiles are not bonded to the natural stone; depending on the product range, they are joined by a puzzle interlock or plastic connectors. Water passing through the surface or its joints must be able to drain freely across the natural stone paving.

Natural stone setts and split-faced or irregularly laid natural stone slabs are often too uneven for this type of drainage and support. Convex stones or stones at different levels, wide joints, and settled, tilted or loose elements prevent the rubber tiles from being supported across their entire surface.

Loose or settled stones must be relaid to the same level, while wide or washed-out joints require permanent filling. Any remaining unevenness must be levelled. Where there is extensive settlement or deformation, correcting the bedding layer alone is insufficient.

Once the natural stone paving has been removed, the exposed bedding layer, the underlying sub-base and the formation level must be checked for load-bearing capacity and drainage, then repaired where necessary. A level levelling layer is formed over the load-bearing, compacted sub-base prepared to the required profile. Fillable plastic honeycomb grids, sold as gravel or grass grids, are laid on this layer.

The honeycombs are completely filled with washed, angular, frost-resistant grit and levelled flush with their upper surface. The honeycomb grid prevents lateral movement of the grit and provides a dimensionally stable, level support for the rubber tiles. Drainage must function throughout the sub-base.

Where the natural stone was previously laid on concrete in a mortar bed, loose and protruding mortar residues must be removed. The exposed concrete must be load-bearing, level and adequately drained.