Softwood Shiplap Boards V Redwood Treated are used for internal and external cladding and can be installed both horizontally and vertically. It is ideal for use on sheds, garages as well as walls and panelling. The shiplap boards feature a rabbet joint which allows them to be stacked and overlapped for added strength. The cladding can be painted, varnished or stained to match any existing décor. The boards are treated to allow for external use and to prevent rotting and any weather damage.