Construction Technology

Note that on this drawing the hatched portion is a void, not the sectional bond. This bond was an attempt to produce a more weather resis- tant form of wall than the one brick solid wall commonly used in housing at the time, with- out using any more bricks or splitting the wall into two layers joined with wall ties. The idea never took off as the brick which protrudes from one vertical layer and touches the other merely serves to draw moisture from the out- side to the inside face of the wall.

EThe reason risbond appears in the upper sketch of Figure 1.27 is the obsession the brick- layer has had with getting back to a bond which is simply laying each brick half over the one below, and he achieves this in five courses – but it is a visual disaster. A little thought would start this off in course 7 and get back to that in course 1 as shown in the lower sketch. And just to prove that bricklayers like this do exist and it’s not all in the author’s imagination, Figure 1.28 is a photograph of a facing brick wall with one course ventilators built into it. They mostly all looked like the one in the photograph. The photograph was orig- inally taken in colour and the contrast across the different colours of bricks accentuated the risbond as well as showing up more clearly the poor general workmanship in this small area

This is a method of building a half brick thick wall similar to stretcher or common bond but leaving a space between every brick in each course, as shown in Figure 1.29. Therefore the bond can be by quarters or thirds, which describes the overlap of bricks in adjacent courses. With a quarter lap the void is half a brick wide, and with a lap of a third, the void is a third of a brick wide.