With the natural action of the weather, walls suffer erosion which loosen the mortar. Your wall will then not be watertight and will need re-pointing.The joints represent 15 to 25% of the total surface of a wall therefore missing mortar can lead to damp inside your home as moisture can penetrate your exterior walls. Re-pointing is a time-consuming job and you might want to call a professional.
Skill level: 3 – Advanced
- Cement mixer
- Pointing Trowel
- Mortar board
- Scaffolding/ ladder
- Soft brush
- Sand and cement
Step by step guide to repointe a brick wall:
1. With a chisel and hammer, first remove any loose mortar.
2. Your wall will need cleaning with clean water and by remaining moist it will allow the mortar not to set too quickly.
3. Take the mortar back to 15mm off the front of the brick and make sure to brush any dust with a paintbrush.
4.To avoid the new mortar falling out, clean the joints with water.
5. The usual mortar for re-pointing is either a 6:1:1 mix of builders sand/hydrated lime/cement or a 3:1 mix of sharp sand/hydrated lime. Measure the amounts carefully so that each batch will set to a consistent colouring.
6. Mix your mortar and with a trowel push it into the joints firmly starting with the upright joints and then the horizontal one. Re-pointing is normally done from the top of the wall downwards.
7. Only mix a small amount of mortar as it takes time and your mortar will start going off.
8. To give the required finish, there are various techniques.
9. The penny pointing technique, rolling an old penny in the middle of the joints, leaving a straight line in the mortar.
10. Bricks being mass-produced today, a flushed finishing can be hard to achieve. You need to draw a strip of wood about 12mm wide, 6mm thick and 100mm long along the joints after the mortar has started to go off.
11. A very difficult technique for a diyer is the weathered finishing created joints of consistent depth; it requires a steady hand and a lot of skills. However this is probably the most durable red bricks mortar joints.
12. Once the mortar has set, use an old broom to remove any excess, stains or dust. If the stains persist, use a brick and rub it against them.
For the small story, there is a technique called the Westminster smudge, same process as flush pointing, but with some hidden secrets.
Care and Maintenance:
Depending where you wall is situated, it's worth weatherproofing it with a good water repellent. It will improve insulation and stop water penetrating. Using a brush apply the weatherproofing liquid on all the bricks and the joints.
The information provided in this guide is to be used strictly for guidance only. We recommend you always read the manufacturer's instructions.