Pointing is the dressing of the front edge of the mortar between courses of bricks or stone in a wall. Pointing is often in bad condition on houses and walls that have been neglected, although once done properly pointing should last for decades.
The Importance of Pointing
The reason it is so important is that it helps to make the whole wall smooth so that rain water runs off easily. When mortar starts to crumble and break down water will rest in the damaged sections and penetrate the mortar and brickwork.
Then in the winter the stored water will expand when it freezes then contract when it thaws, weakening the bricks and mortar. Eventually the wall breaks down, so if you are faced with poor quality pointing on a renovation property it is essential to dig out the old crumbling mortar and replace it.
The process of getting the old mortar out is called raking out. An old shavehook (the three-pointed scraper for stripping paintwork off wood mouldings) or a small cold chisel (also known as a bolster) are the best tools for this or you can buy specialist mortar raking chisels. There are also joint raking tools that have a point in between two small wheels.
These are dragged along the joint with the wheels holding the point at the right distance from the surface of the joint. Whichever tool you use, keep scraping until you hit solid mortar then finish off with a stiff brush. A wire brush can be used but it’s probably not the best option on soft stone with lime mortar, as it will be too aggressive.
Getting to the Point
Once that’s all done it’s time to mix up the mortar and start re-pointing. The mix will differ according to the finish you are after and the type of brick or stone you are working with. But as far as consistency goes, once it is in a joint you should be able to press a finger into it and leave an impression, without the mortar sticking to your finger.
Take a large dollop of the mortar and place it on the hawk (the small board with a handle underneath that bricklayers use) then take a small amount on a pointing trowel and press it into the joint. Work your way along the wall using relatively small batches of mortar to prevent it getting too dry before you can use it.
If you are aiming for a simple weatherstruck joint then press the mortar in at the top of the joint and scrape it off on the bottom edge. This gives a slight slope to the pointing which encourages water run-off.
Getting Help and Watching the Weather
Pointing is much easier with two people, one to mix, fetch and carry the mortar while the other does the pointing. The second person can then also be finishing off the pointing later on.
This is following the pointer once the mortar is semi-set, rubbing off bobbles and blobs of mortar before they set properly. With rough stone finishes it is also necessary to press the mortar in in places to make sure there are no airholes.
Timing and the weather are very important with pointing. If it is too hot the mortar will dry too quickly and shrink away from the surfaces or the brick and stone, not forming a proper seal. This can be controlled to a certain extent by modifying the mortar mix and soaking the wall periodically but this does need skill and experience. If it is too cold or wet then the mortar won’t set properly either.
There are many different pointing styles and there isn’t the space to cover them here. they will differ depending on the look you want, what’s been used on other property nearby, the styles that are common in your part of the country and the ferocity of the weather you experience. We cover some of the most popular pointing styles and how to create them in another article in this section.