A generic term for a head jamb. Unlike the lintel *magusa まぐさ, kamoi normally have tracks for sliding doors or partitions. Also called uchikamoi 内鴨居. Older head jambs are thicker than later ones. The length equals the inside measurement of the width of an opening for installing either a single sliding door *hikido 引戸 or double sliding doors *hikichigai 引違. There are several types:
1 Sashikamoi or sashigamoi 指鴨居, also written 差鴨居 are frequently used in vernacular houses in regions with heavy snow. The heavy lintels are 21 cm - 60 cm high, significantly greater than the usual 6 cm of a kamoi. It serves not only as a track for sliding doors but as a structural member as well. Because of its size, it is impossible to insert the ends into the posts or pillars. Therefore, tenons are added to the ends of the sashikamoi and inserted into mortises made in the posts. The blind, wedged, angle joint *jigokuhozo 地獄ほぞ is commonly used. This method is called hozosashi ほぞ差; sashihozo 差ほぞ; sashimono 差物.
2 *Usugamoi 薄鴨居 are used for a transom *ranma 欄間 and in tea ceremony house *chashitsu 茶室 and are therefore smaller other usual.
3 Hitosujigamoi 一筋鴨居 is used in tea ceremony houses *chashitsu 茶室 and has only a single channel.
4 Mumegamoi or *mume 無目 is similar to a lintel in that it has neither a track added nor a groove cut.
5 Tsukegamoi 付鴨居, also pronounced tsukekamoi, meaning attached kamoi; sometimes called yosetsukekamoi 寄付鴨居, is an ornamental timber attached to the surface of the wall between two visible posts and adjacent to an opening for a window, for example, at the same height as the kamoi. The older style head jamb was made by making channels on a strip of timber and nailing it to the lintel. Later the channels were cut directly into the head jamb with a chisel and plane.
6 Nakakamoi 中鴨居 is a lintel placed between the sill *shikii 敷居 and the top lintel, kamoi. See *nakashikii 中敷居.
