Header: The Brick That Wears Its Narrow Face

To most people, a header is a piece of protective headgear, or the top section of a page or document. But on a construction site, a header is a brick positioned with deliberate care and purpose. When a mason lays a header, the brick goes down on its largest face, but the end grain, the smallest dimension of the brick, shows on the surface of the wall. This orientation matters intensely because it determines both how the wall holds together and how it looks.

Headers serve a critical structural function in masonry. When bricks are laid lengthwise along a wall, they are called stretchers. Headers tie the outer and inner leaves of a double-thickness wall together, running perpendicular to the stretchers and interlocking the layers. Without headers, the two sides of a cavity wall or a composite brick wall could separate under load or movement. Headers appear at regular intervals, sometimes every sixth course, as part of a bonding pattern that holds the entire structure together. The pattern itself has names: Flemish bond alternates headers and stretchers in each course; English bond runs full courses of headers between courses of stretchers.

The term originated from the position and function rather than appearance. A header comes at the head, or boundary, between two areas, it spans from the outside face of the wall to the inside, thus its smallest dimension runs perpendicular to the wall plane. The word crossed from architecture into other building trades, now also referring to beams that sit perpendicular to joists, or ducts that distribute air, all carrying the sense of 'something that leads across or connects.'

In industrial electronics, the term has borrowed this directional sense. A pin header is an array of male electrical pins arranged perpendicular to the circuit board, their rows and columns creating connection points that lead outward from the board. The parallel is structural: just as a brick header ties two materials across a boundary, a pin header ties two electrical systems across an interface. The logic of the name transferred cleanly even though electricity and masonry share nothing else.