21 x 145mm Larch square profiles can be used for a variety of cladding and fencing applications this profile can be used as an open or closed board, board on board, Board on Board lapped, Yorkshire Boarding configuration, it can be used as trims for corners reveals. The surface is precision planed smooth. To help maintain its colour you can apply the larch wood finish with UV protection. If left untreated larch will turn to a golden brown colour before turning to a silvery grey colour.