- A short piece of wood, usually a 2" x 4" or 2" x 6", placed horizontally between the studs of a wall. Firestops are equal in width to the studs. They are usually placed halfway up the height of the wall to slow the spread of fire by limiting drafts in space between the sheathing on the two sides of thewall. building codes usually do not require firestops in walls that are less than 8' high.
- masonry units placed in wood framed walls.