Most people are aware of how a wall works, a series of bricks are installed one on top of another on a bed of mortar. The process is straightforward however it is important that the work is undertaken accurately and competently and that the wall is adequately pointed on completion. Pointing is the process of installing a final finish to the wall between the bricks which can often account for between 10 and 15% of the wall surface and so has a very important role both in making the wall aesthetically pleasing and keeping it weathertight.
If the wall is inadequately pointed this can irreparably damage buildings particularly older buildings which have softer brickwork. In this blog we will look at some of the more common styles of pointing and talk briefly about the correct way to install pointing and some of the mixes which are best for certain scenarios.
The first style of pointing which is perhaps the most common is flush pointing, an example of which can be seen in the diagram below. In this instance cement pointing is simply installed flush with the surface of the wall.
Another common style of pointing is sometimes referred to as bucket handle or concave pointing in which the cement is installed much as it is in the case of flush pointing but a rounded tool is then used to give a concave finish.
The next style is called weather struck pointing where the cement is installed and then given an angle down and away from the face of the wall.
A less common style of pointing but one which is seen from time to time is recessed pointing where pointing is simply installed in the wall but set back from the surface and given a vertical finish.
Finally we look at tuck pointing. This is a less common style of pointing where the cement is given a colouring so that it looks the same as the brickwork and then whilst still wet a bead of lime putty is installed in the wall and cut to very straight lines. In this way older uneven brickwork can be made to look as if it is very uniform and so this style of pointing is more common on older walls where brickwork of the time was of lower quality and therefore uneven. This style of pointing is not particularly common and is something of a dying art.
It is important to note that when installing pointing, the old pointing must be removed fully and the mortar between brickwork ground back to at least 15 to 20 mm. In this way the new pointing which is installed will have a longer lifespan and will be less likely to fall out during the colder winter months.
When pointing older walls is not possible normally to install a sand and cement pointing mix as this will be too hard. Hard cements with old soft brickwork will cause spalling to occur and this is something that was looked at in an older blog which can be found here:https://www.thehoppspartnership.co.uk/blog/brick-d...
Therefore older brick walls will normally need a softer mortar which will allow water to dry out through the pointing rather than through the brick and in this instance it is common to use what is known as a gauged mortar. In modern terms this normally comprises of sand, cement, lime and water however in some listed buildings it will be necessary to use older styles appointing which can comprise simply of lime and sands or other aggregates.
There are also different types of sand which can be used some of which are more impervious to water penetration such as sharp sand, this is often used in roofing applications.
When using a tool to shape the pointing this has the added benefit of compacting the mortar and bringing some of the cement paste onto the surface making it better at shedding water away from its surface.
If you have any queries or concerns, feel free to give us a call.