What is the difference between puzzle joints, plug-in connectors and concealed puzzle joints?
WARCO offers several connection systems for floor tiles, each differing in design, installation method and visual appearance. Below is an overview of the key differences:
Puzzle joint (visible)
In this system, the tile edges feature an interlocking profile reminiscent of classic jigsaw teeth or mushroom-shaped connectors. During installation, the profiles of adjacent tiles interlock to form a continuous connection across the full tile thickness.
The joint profile may be formed directly during pressing or precisely cut after the tile has cured. Whether the joint is visible in the finished surface depends on the edge finish (e.g. with or without chamfer) and the surface colouration.
The symmetrical shape ensures uniform load transfer and makes this type of joint the most mechanically stable option.
Plug-in connectors (plastic dowels)
This system uses separate connecting elements, typically round plastic dowels, which are inserted into pre-drilled holes along the sides of the tiles. The tiles themselves have smooth, straight edges similar to precast concrete slabs.
Installation is carried out in a half-bond (stretcher bond) pattern: each tile is connected via dowels to two tiles in the row above and two in the row below. This prevents lateral shifting, although some movement along the length of the dowels remains possible. For this reason, an edge restraint must be installed around the perimeter to stabilise the entire area.
Concealed puzzle joint
This method is based on the same mechanical principle as the classic puzzle joint, but is designed to be invisible in the finished surface. The interlocking profile is located on the underside of the tile, integrated into a rebated step joint.
Two tile edges feature a positive locking profile, the other two a matching negative profile. When laid, the tiles interlock securely from below, forming a durable mechanical connection. From above, the surface appears seamless and aligned, typically with a clean, square joint pattern similar to a chessboard layout.