Basic Joint Finishes
A finish is applied to brickwork mortar joints for a number of reasons. In general terms, a combination of aesthetic and weather-resistance considerations, dependent upon the location of the brickwork and/or its exposure to weather, determines the nature of the joint finish.
The main objective of applying a finish to mortar joints on external brickwork is to seal and compact its surface in order to prevent water penetration into the wall. The secondary objective is to provide a decorative finish to the brickwork. On internal brickwork, the choice of joint finish is wholly an aesthetic one. There are a variety of different joint finishes available, a number of which are more commonly used than others.
It is important to understand the difference between the terms ‘pointing’ and ‘jointing’, which are often confused and used incorrectly. ‘Pointing’ refers to the filling of existing joints with mortar followed by the application of a joint finish (in other words, jointing). It is generally associated with the raking out of decayed mortar joints (to a depth of 15mm) in old or existing brickwork, followed by re-pointing with new mortar and the application of a joint finish.
‘Jointing’ is the term generally used when the mortar joints have a joint finish applied to them as the work proceeds. It is often referred to as ‘jointing-up’ and is a process associated with the construction of new brickwork.
Jointing should never be considered as merely a minor detail or something to be rushed. The choice of joint finish, the skill with which the joint finish is applied by the bricklayer, and allowing enough time to joint-up all have a fundamental bearing on the durability and appearance of finished brickwork. Poor-quality jointing can make excellent
brickwork look distinctly average, whereas good-quality jointing can give average brickwork a visual lift, to the point where it can look quite good!