How do visible jigsaw interlocks, plastic connectors and concealed jigsaw interlocks differ?
Visible jigsaw interlocks, plastic connectors and concealed jigsaw interlocks differ in their edge profile, joint appearance, available laying patterns and whether the tile area requires bonding or a perimeter restraint. Three variants are used for tiles made from rubber granules: visible jigsaw interlocks, plastic connectors and concealed jigsaw interlocks. With visible jigsaw interlocks, the toothed edge engages with the adjacent tile over the full tile thickness. Depending on the range, the teeth are dovetail-shaped or rounded, and are formed during pressing or cut from the tile at the factory after several days of curing. How clearly the tooth pattern remains visible across the surface depends on the edge design and colour. Where all four sides have the same tooth pattern, tiles can be laid in any direction; where the side profiles differ, the laying direction is fixed. This is the most stable of the three systems and holds the tile area together without bonding or a perimeter restraint.
Where bonding or a perimeter restraint is required, tiles with plastic connectors have straight edges and are joined by cylindrical plastic connecting pins inserted into factory-made holes in the tile sides. They are laid row by row in a half-bond installation. Each tile connects to four neighbouring tiles, with two in the preceding row and two in the following row; tiles within the same row are not connected. The plastic connector fittings limit movement across the pin axis, while tiles can still move along that axis. The tile area therefore needs bonding or a fixed perimeter restraint acting along the pin axis. An existing parapet or wall can often provide this restraint, as can an adjacent lawn at the same level, holding the tiles laterally.
Unlike the straight edges used with plastic connectors, concealed jigsaw interlocks place the toothed profile in a step on the underside, outside the visible edge area. Two tile sides carry the projecting profile, with the matching profile on the two opposing sides, which determines the laying direction. The interlock is not visible from above and the joints run in straight lines. Tiles can be laid in a stack bond or a one-third offset. Because the interlock sits within the step, the joint does not extend down to the sub-base, which remains fully covered.