A joint comprising: a tenon, a mortise for receiving the tenon, an aperture formed in one of the tenon and an interior wall of the mortise and a pin which extends from the other of the tenon and the interior wall of the mortise; wherein the aperture is a hole which is engaged by the pin in use such that the tenon is supported within the aperture, and the tenon is capable of vertical and horizontal motion within the mortise in a plane substantially orthogonal to a longitudinal axis of the pin, the motion being limited by the edges of the aperture.