For all walling that exceeds the length of a spirit level, a string-line must be used for running-in to ensure good and straight alignment of brickwork in between the two ends. The string-line is attached at each end/corner of the wall using one of two basic methods.
The first method uses a pair of steel pins (see Fig 81), approximately 125mm long with sharp, flattened ends, pushed into the joints of the brickwork. The use of pins has a number of disadvantages. The pins physically damage the mortar joints, which must be made good later; clumsy use of pins can disturb the brickwork itself; and it can often prove difficult accurately to align the line with the top arris of the bricks, which is made worse by the habit that pins have of working loose. Most bricklayers avoid using pins unless they have to; the main use of line pins is as something to wrap the string-line around when it is not in use.
Fig. 81 Bricklayers’ lines and pins.