Pointing needs replacing when the mortar has receded, is crumbling to powder, or can be raked out with a key. The critical decision is the mix: mortar should be weaker than the brick, so a hard cement mix on soft older brick transfers the damage to the brick face, which cannot be replaced. On pre-1900 property that usually means lime.
- Mortar should always be the sacrificial layer. If the brick is spalling, the mix was too strong.
- Joints are raked to roughly twice their width, not skimmed over.
- Angle grinders widen joints and damage brick arrises. Hand raking is slower and right.
- Weathered pointing with sound depth behind it does not need doing.
The principle behind all of it
Traditional masonry works on a hierarchy: each layer should be weaker and more permeable than the one it protects. Mortar weaker than brick, render weaker than mortar.
The reason is that something always has to give. Walls move, salts crystallise, water freezes. The design intent is that the damage lands in the mortar joint — which is cheap, accessible and replaceable — rather than in the brick, which is none of those things.
A hard cement mortar inverts that. It is stronger and less permeable than an older brick, so when something has to give, it is the brick face that spalls off while the pointing survives intact.
This single principle explains most of what follows, including why the mix matters more than the neatness of the finish.
When pointing actually needs replacing
| What you see | Needs repointing? | Note |
|---|---|---|
| Mortar receded more than a few millimetres | Yes | Water is now sitting on the brick edges |
| Mortar crumbles to powder when rubbed | Yes | No strength left |
| You can rake it out with a key or screwdriver | Yes | Failed |
| Cracks running through joints | Investigate first | Could be movement, not pointing |
| Vegetation growing from joints | Yes, locally | Roots open the joint further |
| Damp inside on that elevation | Likely | Check other causes too |
| Surface weathered but sound behind | No | Cosmetic; leave it |
| Hard cement pointing, brick spalling | Yes — and change the mix | The pointing is causing the damage |
The last row is the one that surprises people. Sound-looking, intact cement pointing surrounded by crumbling brick faces is a sign the pointing is the problem, not the solution.
Choosing the mix
There is no universal answer, and the right one depends on the brick rather than on preference.
Lime mortar
Soft, permeable, and the correct choice for most pre-1900 solid-wall property and for any soft handmade brick. It accommodates movement, lets the wall breathe, and sacrifices itself rather than the brick. It is slower to apply, needs protecting from frost and rapid drying while it cures, and wants someone who has worked with it. On a listed building or in a conservation area it may be required rather than preferred.
Cement mortar
Appropriate on modern brick designed for it — generally post-war construction with harder, less permeable bricks. Faster, more forgiving to apply, more weather-tolerant during curing. The failure mode is using it on an older wall, where it is too hard and too impermeable for the brick behind it.
The test if you are unsure
Look at what is already there and at the brick itself. Soft, slightly irregular handmade bricks with a lime-mortar joint should be repointed in lime. Hard, regular, wire-cut bricks with existing cement pointing are fine in cement. Where there is doubt on a period property, the cautious answer is lime, because it can never damage the brick.
How it should be done
- Rake out to depth. Roughly twice the joint width, so the new mortar has body. Skimming a thin layer over failed mortar produces pointing that falls out within a few years.
- By hand where the brick is soft. Hand tools are slower and they do not widen the joint or damage the brick edges.
- Clean and damp down. Dust prevents bonding, and a dry wall pulls the water out of the new mortar before it can cure.
- Mix to match — the right binder, and sand that matches the original in colour and grading, which is what makes a repointed wall look right.
- Fill in layers on deep joints rather than in one pass.
- Finish to match the existing profile. Flush, bucket-handle, weather-struck or recessed — matching what is there matters more than which is technically best.
- Protect while curing. Particularly lime, which needs shielding from frost, direct sun and drying wind for some time.
The angle grinder problem
This is the most common way repointing goes wrong, and the damage is permanent.
Raking joints by hand is slow. An angle grinder is much faster, and on hard modern brickwork with wide joints it can be acceptable in careful hands.
On older brickwork it is not. Original joints were often very fine, and a grinder disc is wider than the joint. The result is widened joints that will never look right again, and chipped brick arrises along every course. From a distance the wall looks oddly striped; close up, the edges are gone.
It is also irreversible. You cannot un-widen a joint, and replacing the brick faces is an enormous job.
If you are getting an older property repointed, ask directly how the joints will be raked. A contractor who says hand tools on soft brick is telling you they have thought about it.
Spalling brick, and what can be done
Spalling is when the face of a brick blows off, leaving a rough, recessed surface that then weathers faster still.
The causes are water and freezing: a brick that stays saturated, usually because something is keeping it wet, has the water in its pores expand in frost and push the face off. Hard pointing contributes by preventing the joint from doing its job. Impermeable paints and coatings do the same.
Isolated spalled bricks can be cut out and replaced with a match, which is the best outcome where the brick is obtainable.
Scattered spalling can sometimes be addressed with brick slips or by turning sound bricks where access allows, though both are laborious.
An extensively spalled elevation realistically leaves three options: accept the appearance, apply a breathable render, or re-face. All of them are substantial decisions, which is why dealing with the cause early matters.
In every case, find out why that wall is staying wet — a gutter, a bridged damp-proof course, raised ground — before doing anything else.
What it costs
These are the building figures published across this site:
| Job | Typical Coventry guide price | Notes |
|---|---|---|
| Repointing | £20–£50 per m² | Brick condition dependent |
| Builder, hourly | £20–£40/hr (avg ~£24) | Skilled trade |
| Builder, day rate | £200–£350/day | Varies with firm size |
| General building project | £4,600–£14,700 (avg ~£8,593) | Scope dependent |
Repointing is priced per square metre and the range is wide for good reason: hand-raking soft brick in lime is several times the labour of grinding out wide cement joints. A quote at the bottom of the range for a period property is worth asking about.
We identify the brick and the existing mortar before specifying a mix, and we hand-rake where the brick needs it.
Frequently asked questions
How do I know if my pointing needs replacing?
Try raking a joint with a key or a screwdriver. If the mortar comes away easily, crumbles to powder, or has receded more than a few millimetres so water sits on the brick edges, it needs doing. Pointing that is simply weathered on the surface but sound behind it does not.
Should I use lime or cement mortar?
Match it to the brick. Soft, handmade older bricks — generally pre-1900 — need lime, because mortar must be weaker than the brick so the joint takes the damage rather than the brick face. Hard modern bricks are fine in cement. Where there is doubt on a period property, lime is the cautious choice because it cannot damage the brick.
Why is my brick crumbling but the pointing is fine?
Because the pointing is too hard for the brick. When mortar is stronger and less permeable than the masonry, moisture and salts leave through the brick face instead of the joint, and frost blows the face off. Intact cement pointing surrounded by spalled bricks is a classic sign of the wrong mix.
Can repointing be done with an angle grinder?
On hard modern brickwork with wide joints, carefully, sometimes. On older brickwork with fine joints, no — the disc is wider than the joint, so it permanently widens the joints and chips the brick edges along every course. Ask how the joints will be raked before work starts; the damage cannot be undone.
How deep should joints be raked out?
Roughly twice the width of the joint, so the new mortar has enough body to hold. Skimming a thin layer of fresh mortar over failed material is the commonest shortcut and it produces pointing that falls out within a few years, after which the job has to be done again properly.
Can spalled bricks be repaired?
Isolated ones can be cut out and replaced with a match, which is the best outcome. Scattered spalling can sometimes be addressed with brick slips. An extensively spalled elevation leaves you choosing between accepting the appearance, a breathable render, or re-facing. In every case, find out why the wall is staying wet first.
The mix matters more than the finish
We identify the brick and the existing mortar before specifying anything, and hand-rake where the brick needs it rather than grinding. Free survey, fixed written quote.