Constructing an Oversailing Course

An oversailing course needs to project by no more than 30mm. If perforated bricks are being used, the size and position of the holes in the brick will influence how far the oversailing course is projected – it is not desirable to be able to see the holes when looking under the oversailing course. This is more

of an issue on higher walls, where the top of the wall is above head height.

When laying an oversailing course, the basic principles of setting up at each end and running-in in between remains the same; however there a few more issues to bear in mind. When setting up at each end, the projection must be the same at each end and consistent along the length of each brick. This can be checked with a tape measure, but a quicker and more accurate method is to make a simple gauge by notching a small piece of timber to a depth equal to the size of the overhang.

Constructing an Oversailing Course

Fig. 219 Gauging a consistent overhang with a notched piece of timber.

Next, bricks that overhang have a tendency to tip forward simply because they are being bedded on thin air at their outer edge. To overcome this tendency, the mortar for the bed joint should be spread so that it is higher at the outer edge. The oversailing bricks should be bedded on it so that when they are initially laid, they tip the other way in an almost exaggerated fashion (see Figs 220 and 221). The brick can then be adjusted so that it is level across its width.

Having started from an exaggerated position in the opposite direction it is much more likely to stay in its final desired position when adjusted, rather than tipping forward. In other words, the natural tendency of the oversailing brick to tip over is being used to the bricklayer’s advantage.

Constructing an Oversailing Course

Fig. 220 Exaggerated spreading at outer edge of bed joint for laying oversailing bricks.

Constructing an Oversailing Course

Fig. 221 Oversailing brick initially laid out of level, prior to adjustment.

Oversailing bricks must always be checked for level across their width, even when being laid to a line. The fact that they project from the face of the

wall means that there is no lower reference point to which to flush up the bottom edge of the oversailing brick (see Fig 222).

Constructing an Oversailing Course

Fig. 222 All oversailing bricks must be checked for level across their width.

The height of the wall also dictates the way in which an oversailing course is run-in; specifically, whether it is run-in to the top edge or the bottom edge. Where projecting brickwork is concerned, the eye tends to be drawn to the nearest, prominent edge. On a high wall, the observer’s eye will be drawn to the bottom edge, which is the nearest. If the top edge of the oversailing course on a high wall is run-in to a line, any slight deviation in brick thickness will show as an undulating deviation in that bottom edge. On this basis, oversailing courses on high walls tend to be run-in to the bottom edge of the bricks.