Partition wall

A partition wall that is a fire-resistant partition wall, comprising:

• a plurality of wall studs installed at predetermined intervals;
• and
• a first wall and a second wall that are a pair of walls provided across the plurality of wall studs from each other, the first wall and the second wall being formed of a plurality of vertically and laterally arranged gypsum boards,
• wherein each of the first wall and the second wall is a single-layer wall of the plurality of gypsum boards,
• vertical joints and lateral joints are formed in each of the first wall and the second wall,
• the wall studs are on a back side of the vertical joints,
• a joint base member having a fire blocking capability is provided at the lateral joints, the joint base member including a back piece contacting a back side of the gypsum boards and a projecting piece projecting from the back piece in a thickness direction of the gypsum boards, wherein a cross section of the joint base member perpendicular to a longitudinal direction thereof has a T-letter shape,
• the gypsum boards, the joint base member, and the wall studs are not screwed with a common screw, and
• (a) the gypsum boards are screwed to only the wall studs and are not screwed to the joint base member, and the joint base member is fixed to a position of the lateral joints by being inserted between the gypsum boards and the wall studs, or
• (b) the gypsum boards are screwed to the wall studs and to the joint base member with different screws, and the joint base member is fixed to a position of the lateral joints by being inserted between the gypsum boards and the wall studs.