How to Repoint Brickwork: Tools, Method and Costs
Repointing is the replacement of the outer layer of mortar in brickwork joints. Done properly it keeps water out and can add decades to a wall. The hard part is not the pointing - it is raking out the old mortar cleanly, to the right depth, without damaging the bricks and without filling the site with silica dust.
Does your brickwork actually need repointing?
Look for:
- Mortar that crumbles when scraped with a screwdriver or key
- Joints recessed well behind the brick face, or visibly hollow
- Damp patches inside on an external wall
- Loose or moving bricks
- Vegetation or moss taking root in the joints
Sound mortar that is merely weathered does not need replacing. Repointing an entire wall when only a patch has failed is wasted money - and needlessly disturbs sound work.
How deep should you rake out?
The standard guidance is roughly twice the joint width, which on typical UK brickwork means 15-20 mm. Too shallow and the new mortar has nothing to grip - it will pop out within a couple of winters. Too deep and you risk disturbing the bedding mortar behind.
Rake vertical (perpend) joints as well as horizontal beds. Consistent depth across the whole area gives an even finish.
What tools do you need?
1. Raking out
Three realistic options:
| Method | Speed | Notes |
|---|---|---|
| Hand chisel (plugging chisel) | Very slow | Total control. Fine for small patches and fragile heritage work. |
| Angle grinder + raking blade | Fast | The common trade approach. Needs care near brick arrises and proper dust control. |
| Diamond router / rake pin | Fastest - up to 1.5 m per minute | Routs both vertical and horizontal joints. Fits standard 4½″ and 5″ grinders. |
A diamond routing setup runs at roughly 48 pence per linear metre in consumables and cuts brick and mortar however hard - unlike carbide-based systems, which struggle once mortar gets above medium hardness. Routing widths of 6 mm and 8 mm cover standard UK joints.
It is also far kinder to work with than the dedicated oscillating saws it replaces: around 5.0 m/s² vibration versus roughly 7.7 m/s², about 90 dB versus 108 dB, and roughly 1.5 kg of tool weight versus 4.3 kg. Over a full day on a wall, that difference is the difference between finishing comfortably and not.
2. Dust control
Not optional - see the section below. You need a dust extraction cutting guard or dust shroud connected to an M-class vacuum. Used with suitable extraction, diamond routing is effectively dust free.
3. Pointing up
Pointing trowel or finger trowel, hawk, mixing bucket, stiff brush, and a jointer matched to the finish you are replicating.
Dust, silica and the law
Cutting mortar and brick releases respirable crystalline silica (RCS). Long-term exposure causes silicosis and is linked to lung cancer - and HSE enforces a workplace exposure limit for it. Dry-cutting mortar with an unguarded grinder generates RCS far in excess of what is acceptable.
In practice, control means:
- On-tool extraction - a shroud or guard connected to an M-class (or better) vacuum
- RPE appropriate to the task, correctly fitted
- Not dry-sweeping the debris afterwards - vacuum it
This is a legal duty on site, not best-practice advice. It is also why the dust guard is the single most important accessory in a raking kit.
Step by step
- Pick your weather. Above 5°C, no frost forecast, not in blazing sun. New mortar must not freeze or flash-dry.
- Set up extraction. Fit the dust guard, connect the vacuum, put your RPE on.
- Rake out to 15-20 mm. Horizontals first, then perpends. Keep the blade off the brick faces - you are removing mortar, not reshaping bricks.
- Brush and vacuum out. Every joint must be clear of loose material.
- Damp the joints. Lightly - damp, not saturated. Dry brick sucks water out of fresh mortar and kills the cure.
- Mix to match. Match the original mortar, not modern default. On older or solid-wall properties that usually means a lime mix; a hard cement mortar on soft historic brick traps moisture and spalls the brick faces.
-
Press it in. Fill perpends first, then beds. Work the mortar hard into the back of the joint in layers - voids are where water gets in.
A pointing gun gets mortar to the back of the joint with less waste down the wall. -
Finish when thumbprint-hard. Match the existing profile: struck, bucket-handle, weatherstruck or flush.
Work the joint when the mortar is thumbprint-hard to match the existing profile. - Brush off and protect. Brush lightly once set, then keep the work damp and shaded for a few days in warm weather.
What does repointing cost?
Consumables are the small part - roughly 48p per linear metre for diamond routing. The real cost is labour, which is entirely determined by how fast you can rake out. At up to 1.5 m per minute, a diamond router transforms the economics against chiselling by hand.
The kit itself is modest if you already own a grinder: a rake pin or blade is £8-£26, a starter kit around £33-£41, and the dust guard £27-£28.
Recommended kit
| Product | Best for | From |
|---|---|---|
| Mortar Rake Bit for Angle Grinder M14 | Occasional patch repairs | £8.99 |
| Ultimate Repointing Blade | Fast raking, all angle grinders | £7.99 |
| Superior Mortar Raking Blade | Harder mortar, longer life | £12.95 |
| Expert Pro Mortar Raking Blade | Daily professional use | £19.95 |
| Diamond Mortar Rake Pin (M14) | Routing both joint directions | £25.50 |
| Dust Extraction Cutting Guard | Silica control - 115/125 mm | £27.45 |
| Repointing Starter Kit | Everything to start - best value | £32.95 |
| Diamond Mortar Rake & Guard Kit | Rake plus dust control together | £40.95 |
See the full mortar raking and repointing range.
Frequently asked questions
How deep should mortar be raked out before repointing?
Around twice the joint width - typically 15-20 mm on UK brickwork. Shallower than that and the new mortar will not hold.
Can I repoint with an angle grinder?
Yes, and most trades do. Use a purpose-made raking blade or rake pin, fit a dust extraction guard connected to an M-class vacuum, and keep the blade clear of the brick faces.
What mortar should I use for repointing?
Match the original. Older solid-wall and heritage properties generally need a lime mortar; using hard cement mortar on soft historic brick traps moisture and causes the brick faces to spall.
What time of year is best for repointing?
Spring and early autumn. Work above 5°C with no frost forecast, and avoid direct summer sun which dries mortar before it cures.
How long does repointing last?
Correctly raked, mixed and finished, repointing should last for decades. Most early failures trace back to raking out too shallow or using an unsuitably hard mix.
Planning a repointing job? Talk to us about the right blade for your mortar hardness - it makes a bigger difference to raking speed than anything else.