Brick Reparation Guide - How to Expand Brick Life?

Brick repair covers the maintenance, restoration and replacement of deteriorating brickwork on existing buildings. Common repair tasks include repointing failed mortar joints, treating moss and biological growth, addressing spalling and surface erosion, and matching replacement bricks for extensions or patching. Properly maintained brick buildings can last 150 years or more — the key is early intervention before minor deterioration becomes structural damage.

Bricks are eco-friendly, aesthetically appealing, and one of the most durable building materials ever - numerable buildings are living proof. Unfortunately, although bricks weather well with time, poor brick repairs or lack of upkeep severely reduce brick life.

Cracks, chips, and other brick damage signs put your building project at risk.

Here at UK Brick, we frequently get asked about the best practices to maintain brickwork and make bricks last longer. We also offer an array of top-quality bricks that blend in and match your reparation project.

We love bricks, and we want to help you repair your bricks to augment brick life.

This guide for architects addresses our favourite recommendations to expand brick life and best brick maintenance practices.

What causes brick deterioration?

The most common causes of brick deterioration in UK conditions are failed or eroded mortar joints allowing water ingress; frost damage and spalling caused by water freezing within the brick face; biological growth — moss, lichen, algae — on north-facing or shaded elevations; efflorescence, the white salt deposits drawn to the surface by moisture movement; and impact damage or structural movement causing cracking. Most of these conditions are progressive — caught early, they are straightforward to address; left untreated, they become structurally significant and expensive.

Understanding the cause before starting any repair is critical. Repointing mortar joints will not solve a problem caused by structural movement. Treating moss will not address an underlying water ingress problem from a failed roof detail. Always identify the root cause first, restrict repairs to the minimum necessary, and preserve the building's original material wherever possible.

Annual brick inspection checklist

It's crucial to inspect brickworks at least once a year to check for common maintenance issues to prevent further complications. Key brick aspects to look after are:

• Damaged mortar joints – patch with new mortar as soon as possible to avoid water absorption.
• Moss – If the building receives no sunlight, it'll likely result in moss, mould, or mildew because bricks are porous and retain moisture. It's important to brush it off immediately. Many practitioners recommend mixing water and bleach for this purpose; however, be aware that bleach can damage the façade.
• Plant growth – plants and other veins adhere to the brick face, erode it, or even crack it. Don't pull plants or veins directly from the brick; instead, we recommend cutting them as close to the soil and letting the plant fall off the brick naturally.
• Efflorescence – when water penetrates the brick, salt and other crystals may grow on the brick. This can be easily spotted on the face of the brick as a chalky cumulus. Often, efflorescence can be removed with a brush and, in the worst-case scenario, with other chemical agents.
• Spalling – brick faces that are flaking, delaminating or pitting indicate frost damage. Spalled bricks cannot be repaired by repointing or cleaning — they need replacement. Note the extent and pattern of spalling before specifying remedial work.
• Cracking – hairline cracks in mortar joints are usually thermal movement and low risk. Stepped diagonal cracks through mortar joints, or cracks running through brick faces themselves, indicate structural movement and require specialist investigation before any repair work begins.

How to repair deteriorated brickwork

Firstly, it's critical to figure out what's causing the damage.

We recommend restricting repairs to the bare minimum to preserve the building's authenticity and avoid brick decay associated with poor maintenance or unsuitable alterations.

However, it might be indispensable because of design deficiencies, craft or materials.

If bricks are severely damaged, cut out mortar with a chisel and replace them.

It can be challenging for architects to find replace bricks with the exact same characteristics (colour, texture, size…). That’s why our wide catalogue offers bricks for every project.

For better results, we recommend laying the replacement bricks with the same type of bond (i.e. [hit and miss brick bond]) as the initial construction. Further, leaving the replacement bricks to blend in naturally over time is preferable to attempt and tone them down.

In short, brickwork will only need to be taken down and rebuilt in extraordinary instances - where the building is too damaged or doesn't meet safety requirements.

When replacing individual bricks, always order 10% more than calculated to allow for cutting waste and future repairs from the same batch. Batch variation between orders — even from the same manufacturer — means replacement bricks sourced later may not match the original exactly in colour or texture.

Matching replacement bricks for repairs and extensions

Matching replacement bricks for a repair, extension or patch is one of the most common challenges in UK construction — and one of the most frequently underestimated. The key variables are colour tone, surface texture, format and mortar colour. Each of these can shift the perceived match significantly, even when the brick specification appears identical on paper.

Photograph the existing brickwork in both wet and dry conditions — the colour shifts significantly between the two states — and compare samples on site in natural daylight before committing. Assess the sample panel at different times of day and in both overcast and direct sunlight. Mortar colour is equally important: a lighter mortar will make the brick read lighter; a darker mortar creates a more monolithic effect. Always match the mortar as carefully as the brick.

UK Brick's team can advise on the closest match from the range and provide samples for on-site comparison. Contact us with photographs of your existing brickwork for a match recommendation.

[Browse red bricks] · [Browse buff bricks] · [Browse brown bricks] · [Browse grey bricks] · [Browse the full range] · [Contact us for a match recommendation]

Should you seal or treat brickwork?

Different methods claim to protect your project bricks from dampness, moss, efflorescence, etc. Such as sealing brickwork with non-breathable sealants, treating brickwork with water repellent or tanking the interior of brickwork, among others.

However, brick walls are designed to breathe, allowing the construction material to dry out when dampness has penetrated.

Therefore, UK Brick and the Brick Development Association believe that using sealing, water repellent, and other treatments on your brickwork can shorten brick life. These brick treatment methods are unnecessary because UK Brick's bricks are already well prepared for weather conditions.

When to repair vs when to replace brickwork

Repair is always preferable to replacement — it preserves the original material, avoids the matching challenge, and maintains the building's historic character. The following situations require replacement rather than repair:

• Spalling beyond the fired outer layer — once frost damage has penetrated through the fired face into the brick body, the structural integrity of the unit is compromised. Repointing will not resolve it.
• Frost damage to the brick core — visible as crumbling, splitting or progressive disintegration of the brick body rather than the face alone.
• Structural cracking through brick faces — cracks running through bricks rather than mortar joints indicate the unit itself has failed under load or movement. Replace and investigate the cause.
• Biological growth causing surface erosion — moss and lichen left untreated for extended periods can erode the brick surface to the point where the fired outer layer is lost. At this stage cleaning will not restore the brick face.
• Incorrect original specification — bricks specified for an internal or sheltered application but exposed to UK weather conditions will deteriorate progressively regardless of maintenance. Replacement with a correctly specified brick is the only lasting solution.

When replacing, always match the original bond pattern, use a mortar specification compatible with the original construction, and leave replacement bricks to weather and blend naturally rather than attempting to artificially age or treat them.

Conclusion

Appropriate brick reparation is vital to expand brick life and maintain buildings.

Avoid brick treatments because these don’t let the brick breathe naturally and excavate brick health. On the other hand, the quality of our brick responds well against weather conditions - setting the market standard and being chosen by industry leaders.

Further, many experts now choose UK Brick’s bricks because of their design-led statement and premium Scandinavian clay. UK Brick have also one numerous awards like the ArchDaily Building of the Year Award.

The top-class Scandinavian clay used in UK Brick’s bricks embodies high quality, strength, cost-effectiveness, and sustainability to meet all artistic visions - making the perfect brick visually appealing and functional.

UK Brick is proudly renowned for being London’s leading brick supplier and sustainable pioneer for green building projects.

Don’t compromise. Build with UK Brick.

Explore our bricks and request a free sample or get a quote for your project.

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Frequently asked questions about brick repair

What is the best way to repair mortar joints in brickwork?

Failed mortar joints should be raked out to a depth of at least 15–20mm before repointing with a matching mortar mix. The mortar specification should match the original as closely as possible — a mortar that is stronger than the original brick will cause the brick face to spall rather than the mortar to flex and fail. For historic or older brickwork, always use a lime-based mortar rather than modern cement mixes.

How do I remove moss from brickwork?

Brush off dry moss with a stiff bristle brush rather than pressure washing — pressure washing drives water further into the brick face and can dislodge mortar from weakened joints. Many practitioners suggest mixing water and bleach, but be aware that bleach can damage the façade. A diluted biocide treatment applied after mechanical removal helps prevent regrowth on persistently shaded elevations.

Should I seal or waterproof my brickwork?

UK Brick and the Brick Development Association advise against sealing or waterproofing well-specified brickwork. Sealants prevent the wall from breathing — trapping moisture within the structure rather than allowing it to evaporate naturally. Well-fired facing bricks have a natural resistance to water penetration without surface treatment. Sealants are only appropriate where a brick has been incorrectly specified for its exposure class.

How do I match replacement bricks to existing brickwork?

The key variables are colour tone, surface texture, format and mortar colour. Photograph the existing brickwork in both wet and dry conditions — the colour shifts significantly — and compare samples on site in natural daylight before committing. Contact UK Brick with photographs of your existing brickwork and we can recommend the nearest match from the range.

When should I replace bricks rather than repair them?

Replacement is necessary when brick faces have spalled beyond the fired outer layer, frost damage has penetrated to the brick core, structural cracking has compromised individual units, or biological growth has eroded the brick surface beyond recovery. Surface staining, efflorescence and minor mortar erosion can all be addressed without replacement.

How often should brickwork be inspected?

It is crucial to inspect brickwork at least once a year to check for common maintenance issues and prevent further complications. Early detection of failed mortar joints, biological growth or surface erosion means repairs remain minor and cost-effective rather than structural.

What is efflorescence on brickwork and how do I remove it?

Efflorescence is a white chalky deposit that appears on brick surfaces when water moves through the wall and carries soluble salts to the face. It can be spotted as a pale, powdery residue across the brick surface. Often it can be removed with a stiff brush. In persistent cases, specialist chemical agents may be required. Efflorescence is usually self-resolving as the wall dries out, but recurring efflorescence indicates an ongoing water ingress problem that needs addressing at source.

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