. Disturbing the Line
In order to maintain accuracy when running-in to a string-line, it is important that the line remains as undisturbed as possible. Bricks should be laid as close to the line as possible, but it is too easy to catch the line with the trowel blade and move it out of position, which will affect the finished brickwork. When spreading bed joints, a conscious effort should be made to lift the trowel over the top and well clear of the line. The action of furrowing the mortar bed is the most common cause of the line being disturbed as the line can get pressed down with each downward part of the furrowing action. To avoid this, turn the trowel horizontally through 90 degrees and furrow side to side under the line. This method of furrowing (see Fig 140) is achieved by tilting the trowel blade in the direction of furrowing to push and pull the mortar in both directions along the top of the wall.