What is a wall pier?
A wall pier is the section of wall between two openings — two windows, two doors, or a window and a door — whose height is greater than its width. It is also called a masonry pier or, in Dutch, a penant or muurdam.
In older building literature the term is also applied to a projecting masonry section of a wall face that stiffens the wall or carries the weight of a beam — closer in role to a buttress or a pier.
Why wall piers matter structurally
In a facade with openings, load does not travel evenly downwards. Above each opening sits a lintel or an arch that carries the load out to the sides. All of that load gathers in the wall piers, producing a concentrated compressive load on the foundation and the sole plate beneath.
The narrower the pier and the wider the windows, the heavier that pier is loaded. In older buildings with wide shopfronts, cracks, squeezed-out joints and deflection of the beam below show up exactly at the piers.
Points to watch when altering a building
- Never simply narrow it. Widening a window opening eats into the pier. Have a structural engineer establish the minimum remaining width, including the eccentricity if the load does not act centrally.
- Slenderness. A tall, narrow pier can also buckle. In a cavity wall, whether the inner leaf is properly tied to the floor matters here.
- Damp detailing. The reveals of the openings sit at the sides of the pier. Poorly executed cavity trays and DPCs cause penetrating damp precisely here.
- Historic masonry. Old piers are usually laid in lime mortar. Do not repoint them in hard cement mortar: the bricks then become the weakest element and spall in frost.
Related terms
- Pier
- Lintel
- Reveal
- Facade
- Parapet
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