The Bond a Wall Is Laid In

Two words

A brick laid with its long side facing out is a stretcher. A brick laid with its end facing out is a header. That is the whole vocabulary needed here, and every pattern in brickwork is an arrangement of those two.

The reason it matters is that a header is not a decorative choice. A header is a brick turned sideways to reach into the wall, tying the outer layer to what is behind it. In a solid wall several layers thick, the tying bricks are the only thing making the layers act as one.

What a solid wall needed

An older masonry wall carries load, and a wall that carries load must not be able to split into separate leaves under it. So the courses of stretchers are interrupted at intervals by a course of headers that bond front to back.

Different traditions space them differently, and the spacing shows on the outside as a rhythm:

• A course of headers every sixth or seventh course, with stretchers between, is the ordinary American practice of the nineteenth century
• Alternating headers and stretchers in every course produces a denser pattern used where strength or display mattered
• Headers dropped in singly at regular points, rather than in whole courses, is another solution to the same problem

None of these is better in the abstract. They are answers to how thick the wall is, how much load it takes, what the brick costs, and how fast the mason has to go.

And then the wall changed

In the twentieth century the load moved off the masonry. A frame of steel or reinforced concrete or, in a house, of dimension timber carries the building, and the brick becomes a single skin hung on the outside for weather and appearance.

A single skin has nothing to bond to. It is tied back with metal anchors buried in the mortar, invisible from outside, and it has no structural need for a header at all.

But the pattern persisted, because it was what a brick wall looked like. So bricks were cut in half and laid with the cut end out, producing a course that reads as headers from the street and is nothing of the kind. The same rhythm, the same appearance, no structure whatever behind it.

The consequence for a reader of this catalogue

A bond pattern is evidence of a period, not proof of a construction. A wall showing header courses every sixth course was probably built solid, and might have been built as a veneer by somebody imitating a solid wall. Nothing visible from the sidewalk settles it.

This publication states that limit rather than working around it, because the alternative is a confident claim about a building nobody here has been inside. Where a wall's construction is known, it is known from a drawing, a permit record or an opening, and not from a photograph.

Where the two brick entries meet

The bond is also the joint between the two fired entries in this catalogue. A pressed brick facing needs a common brick backing, and the header courses are where the expensive material and the cheap material are locked to each other. Which is to say the pattern on the front of an old commercial building is a picture of its own economics.