A masonry unit laid flat across a wall so that its shortest end faces outward. In traditional solid brickwork, headers tie two separate wythes together to create a structurally sound, multi-layer wall. In wood framing, the same word describes a horizontal structural beam spanning an opening like a door or window.
Run three stretching courses first, then follow up with a row of headers to tie the outer skin to the backup block.
Because newer cavity walls use metal ties instead of overlapping bricks, true structural headers are rare in new construction, though half-bricks are sometimes used to fake the traditional pattern.
Related terms
Wythe
A continuous vertical section of a masonry wall that is one unit thick.
Course
A single continuous horizontal layer of bricks, blocks, or stone in a wall.
English bond
A bricklaying pattern alternating full courses of headers and stretchers.
Stretcher bond
A masonry pattern where bricks are laid lengthwise with vertical joints offset by half a brick in each successive course.