gō-ita 格板

Also called *ura-ita 裏板. The panel used to fill the space made by the intersecting ribs of a coffered ceiling. If the panels are nailed directly to the ribs, normal expansion and contraction of the wood over a period of time causes the ribs to split and crack. To prevent this, one of two methods may be used. The first is to bore holes into the panel along the edges to be attached to the reverse side of the ribs. Battens are placed over the holes and nailed through the points where the holes are bored. The second method is to place battens wide enough to cover the edges of the panels and to nail the battens firmly to the reverse side of the ribs, thus securing the panels and avoiding nail holes. Usually paulownia, cypress, camphor or zelkova wood are used. Alternating the direction of the grains is common.