WEATHER-STRUCK JOINT FINISH
A weather-struck joint is produced by ironing the joint with the back of a pointing trowel and, at the same time, pressing or insetting the bed joint at the top edge behind the arris of the brick above. This forms a downward, flat sloping surface that finishes at the top arris of the bricks below, allowing rainwater to run off (inspiring the name of the joint). Cross-joints are inset on one side, usually the left. Whether left or right, however, all cross-joints must be struck to the same side, otherwise there will be odd shadow-line effects on the face of the wall.
Fig. 161 Weather-struck joint finish.
The depth of inset must be kept uniform and consistent and the thickness of the pointing trowel is generally regarded as being sufficient. Any deeper insetting tends to result in bold shadow lines that spoil the face of the finished brickwork. Again, cross-joints should be jointed first, followed by bed joints, taking care to ensure that all mortar squeezed out at the arrises of the bricks is carefully and neatly trimmed off with the pointing trowel or tip of the brick trowel. As with half-round jointing, once the bed joints have been finished, the cross-joints must be ‘topped and tailed’, to blend them into the bed joints.
When applying weather-struck joints, care must be taken to ensure that the full depth of bed joints and full width of cross-joints are ironed to a flat sloping finish that meets with the arrises of the adjoining bricks. If this is not done, flat spots will be apparent when trimming off the excess mortar and the joint will have to be ironed again.
An alternative to a weather-struck joint is a struck joint, where the bed joint is inset on the bottom edge. Its limitations on external works are similar to those that apply to a recessed joint.