How can I tell cement pointing from lime?

Cement is grey, hard and often stands proud with sharp edges, and a key will not mark it. Lime is softer, usually paler, sits back within the brick arrises, and can be scratched. If the pointing is clearly harder than the brick beside it, that is the wrong way round.

Does all cement pointing have to come off?

Not always. On a hard machine-made brick in a sheltered position it may cause no harm and is best left alone. It is the combination of hard pointing with soft brick, or with damp appearing inside, that makes removal worth the risk and cost.

Why did damp appear inside after the house was repointed?

Because the wall lost its main drying route. A solid wall absorbs rain and then evaporates it out, mostly through the joints. Seal those with cement and the moisture stays in the wall for longer, which shows up as damp on the internal plaster.

Is lime mortar not just weaker?

It is deliberately weaker, and on an old wall that is the point. The joint is meant to be the sacrificial, breathable part so the brick survives. Strength in the wrong place is what transfers the damage into the brick face.

Caution

Updated 30 August 2026

Cement Pointing On An Old Brick House

Hard grey pointing stands proud of the brickwork and the brick faces around it have started to crumble.

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What's happening?

An old solid brick wall handles water by absorbing it and then letting it evaporate back out. Nothing stops water getting in, so everything depends on it getting out again, and the soft lime mortar joints are the main route — they are more porous than the brick, so they do most of the breathing and take most of the salt and frost damage. Repointing that wall in a hard cement mortar closes the route off. The wall still absorbs water, but now the only way out is through the brick face, so the frost and the salt crystallise in the brick instead of the joint. The result is distinctive: sharp, intact grey ribbons of pointing standing proud, with eroded and spalling bricks between them. The pointing outlasts the wall it was meant to protect.

What usually causes it?

Repointing a soft handmade or early machine-made brick wall in a strong cement mortar
Pointing applied over the brick arrises rather than back within the joint, so it sheds water onto the brick face
Ribbon or strap pointing standing proud of the wall, which traps water behind the raised edge
A cement render or a masonry sealer added on top, closing off what breathing was left
Original lime joints raked out with a grinder, widening them and damaging the brick edges before pointing
Cement pointing used on a wall that also has a failed or absent damp proof course, so trapped ground moisture has nowhere to go
Internal walls dry-lined or sealed at the same time, removing the inward drying route as well

Is it dangerous?

Slowly damaging rather than dangerous. It is a durability fault whose bill grows every winter it is left, because each frost takes more brick face rather than more mortar, and replacing bricks costs far more than replacing joints. The secondary effect is damp: a wall that cannot dry outwards holds moisture longer, which is a common reason a solid wall that was dry for a century starts showing damp on internal plaster after being repointed. On a listed building or in a conservation area, hard cement pointing on historic fabric can also be a consent issue as well as a technical mistake.

Can I fix it myself?

Realistically, no. Cutting cement out of a joint without breaking the brick arrises either side is the hardest routine task in brickwork — the mortar is now stronger than the brick, so a chisel or a grinder takes brick rather than mortar. Amateur removal typically leaves a wall in worse condition than the bad pointing did. What you can do is stop it spreading: do not have the rest of the house pointed the same way, do not add a sealer or a waterproof coating, and clear anything holding water against the wall. Photograph the worst elevations so the extent is recorded before any work starts.

When should you call a bricklayer?

Call a bricklayer experienced in lime work if the pointing stands proud of the brick faces, if bricks between sound joints are eroding, or if damp appeared inside after the house was repointed. Get advice before any work if the building is listed or in a conservation area. Where the brick is soft or handmade, ask specifically about a lime-based mix, because that is the decision the whole repair turns on.

What will the bricklayer actually do?

Assess the brick and the original mortar to establish what mix the wall was built to work with
Cut out the cement pointing by hand, joint by joint, protecting the brick arrises rather than grinding
Repoint in a lime-based mortar matched to the wall's strength, colour, sand and original joint profile
Cut out and replace bricks whose faces have already been lost, matching them to the surrounding wall
Reinstate a joint finish set back within the arrises so the wall sheds water off the brick, not onto it
Protect the new pointing while it carbonates, and advise on removing any sealer or render also blocking drying

Frequently asked questions

We’re happy to answer all your questions.

Sources & References

Crumbling Mortar Between BricksCaution Spalling Or Crumbling Brick FacesCaution Rain Coming Through A Solid Brick WallCaution Crumbling Lime Plaster In An Old HouseCaution

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