How do visible jigsaw interlocks, plastic connectors and concealed jigsaw interlocks differ?

Rubber tiles made from polyurethane bound rubber granulate can be joined by one of three systems, a visible jigsaw interlock, plastic connectors or a concealed jigsaw interlock. The systems differ in the profile formed at the tile edge, the joint pattern, the laying patterns that can be used and whether the completed area needs perimeter edging.

With a visible jigsaw interlock, the tile edge has interlocking teeth. Depending on the product range, the teeth have a dovetail form or a rounded shape, and they engage with the adjoining tile through the full depth of the tile. The interlocking profile is either formed as the tile is pressed or, after the pressed tiles have rested at the factory for several days, cut from the tile. How prominent the tooth pattern looks depends on the edge profile and on the colour of the tiles. If the same tooth pattern is present on all four sides, the tiles can be laid in any direction. If the sides differ, the edge profiles impose a fixed laying direction. The visible jigsaw interlock provides the most stable connection and holds the tiled area together without perimeter edging or adhesive.

Tiles joined with plastic connectors have straight edges. Cylindrical plastic connectors are inserted into factory drilled holes in the sides of the tiles. Installation proceeds row by row in half bond. In this pattern, every tile is connected to four other tiles, two in the preceding row and two in the following row. Tiles next to one another within the same row remain unconnected. Each connector restricts movement across its own axis, while the tiles remain able to move along that axis. The tiled area therefore needs adhesive or fixed perimeter edging that provides restraint in the direction of the connector axes. Often a suitable boundary already exists, such as a parapet or wall. An adjoining lawn that finishes level with the tiled area can also hold the outer tiles at the side.

With a concealed jigsaw interlock, the tiles engage below the visible part of the edge, within a stepped recess on the underside of each tile. Two sides of the tile carry the projecting profile, while the two opposite sides carry the matching counterpart. This arrangement fixes the laying direction. Viewed from above, the interlock remains concealed and the joints run in straight lines. Rubber tiles with this connection can be laid in stack bond, which forms a chequerboard pattern, or in a 1/3 offset. Because the interlocking profiles sit within the stepped recess, the joint does not extend down to the sub-base, which therefore remains fully covered across the whole tiled area.