Common Mistakes When Repointing Brickwork: 7 Errors to Avoid

Repointing can protect brickwork from water ingress, weathering and further deterioration. However, poor preparation, unsuitable mortar or incorrect application can cause more damage than the original problem.

The most common mistakes when repointing brickwork include using mortar that is too hard, failing to match the existing material, removing sound mortar and applying new pointing without first addressing the cause of damp.

Here are seven mistakes to avoid before repairing your brickwork.

1. Using mortar that is too hard

One of the most damaging repointing mistakes is assuming the strongest mortar will provide the best protection.

Many older properties were constructed using softer and more permeable lime mortar. Replacing it with a hard cement-rich mix can prevent moisture from escaping through the joints. The surrounding bricks may then begin to absorb the weathering, frost and salt damage instead.

The Society for the Protection of Ancient Buildings explains that inappropriate hard cement pointing can accelerate the deterioration of older bricks and stone. The replacement mortar should be compatible with the existing wall rather than simply being as hard as possible. Read the SPAB repointing guidance.

2. Failing to match the existing mortar

New mortar should be selected to suit the age, condition and construction of the property.

The colour may be the most noticeable difference, but strength, texture, permeability and finish are equally important. A visually similar mortar may still perform poorly if it behaves differently from the original material.

Older pointing is often best assessed in sheltered areas beneath eaves or other locations that have experienced less weathering.

For professional brickwork repairs and compatible repointing, view our domestic brickwork services.

3. Removing sound mortar unnecessarily

Not every wall needs to be completely repointed.

Historic England advises that comprehensive repointing is rarely necessary. In many cases, work should be limited to exposed sections or areas affected by leaking gutters, rainwater pipes or other specific defects. Sound mortar should normally be left undisturbed. View Historic England’s repointing guidance.

Removing healthy pointing can damage the edges of bricks, increase costs and remove original building material without providing a meaningful benefit.

4. Repointing during unsuitable weather

Mortar needs suitable conditions to set and cure correctly.

Working during very hot, cold, wet or windy weather can affect how quickly moisture leaves the mortar. If it dries too quickly, it may crack or fail to bond properly. If it becomes saturated or freezes before curing, the completed pointing may deteriorate prematurely.

The work should be planned around the conditions, with suitable protection used where required.

5. Failing to prepare and clean the joints

New mortar cannot form a reliable bond if the joints contain loose material, dust or debris.

Failed mortar should be removed carefully without damaging the surrounding bricks. The joints must then be properly cleaned and prepared before the new mortar is installed.

Simply applying fresh mortar over the surface of damaged pointing may improve the appearance temporarily, but thin surface repairs are more likely to loosen and fall away.

6. Filling the joints too shallowly

Repointing should replace the failed material within the joint rather than creating a thin cosmetic covering.

Shallow repairs may not bond securely and can begin cracking or separating after exposure to rain and frost. The depth required will depend on the joint, the masonry and the condition of the existing mortar.

Correct preparation takes longer, but it creates a more durable repair and reduces the likelihood of the same area failing again.

7. Repointing without finding the source of damp

Damaged mortar may be a symptom of another building defect.

Before repointing begins, the surrounding area should be checked for:

• Leaking or overflowing gutters

• Damaged rainwater pipes

• Failed roof or chimney details

• Cracked seals around windows and doors

• Defective render

• Persistent water collecting against the wall

Repointing without resolving the underlying moisture source may only provide a temporary improvement.

Damp patches that become worse after rainfall may indicate penetrating water rather than condensation. Our damp and mould checklist explains how to identify some of the most common causes.

When is repointing urgent?

Arrange an assessment promptly when you notice:

• Deep or visibly open mortar joints

• Loose mortar falling onto paths or roofs

• Bricks beginning to flake or crumble

• Water entering around windows or doors

• Rapid deterioration following frost

• Movement, cracking or loose masonry

Where loose masonry or sudden water ingress could create an immediate risk, use our emergency repair guide to help decide what action to take.

Get your brickwork assessed

Correct repointing should protect the masonry while remaining compatible with the existing building.

Barry Turner & Son provides brickwork repairs and repointing across London, Kent and the South East.

Contact Barry Turner & Son to arrange an assessment or request a quotation.