How to Tell If Your Brickwork Needs Repointing (And What to Do About It)

Most homeowners do not think about their brickwork until something goes visibly wrong. By that point, what could have been a straightforward repointing job has often become a more significant repair. Knowing what to look for — and acting early — can save you a considerable amount of money and prevent long-term damage to your property. This guide walks you through the key signs that your brickwork may need repointing, what causes mortar to fail, and what to do if you spot a problem. ## What Is Repointing and Why Does It Matter? Repointing is the process of removing deteriorated mortar from the joints between bricks and replacing it with fresh mortar. The mortar joints are not just filler — they are a critical part of the wall's structure and weatherproofing. They prevent water from getting behind the brickwork, accommodate small movements in the building, and contribute to the overall strength of the wall. When mortar fails, water can penetrate the wall. In older properties, this leads to damp, frost damage, and — if left long enough — structural problems. Catching it early means a relatively simple repair. Leaving it means a much bigger job. ## Signs Your Brickwork May Need Repointing ### 1. Crumbling or recessed mortar joints The most obvious sign is mortar that is visibly crumbling, powdery, or has recessed back from the face of the bricks. Run your finger along a joint — if mortar comes away easily, or if the joint is more than a few millimetres recessed, it needs attention. Recessed joints allow water to pool and sit against the brick face rather than running off, which accelerates deterioration. ### 2. Cracks in the mortar joints Hairline cracks in mortar are normal and not always a cause for concern. But cracks that run along the full length of a joint, or that open and close with the seasons, indicate that the mortar has lost its flexibility and is no longer doing its job. In older properties that have been repointed with cement, cracking is particularly common — cement mortar is too rigid for the soft bricks used in Victorian and Edwardian construction, and it cracks as the building moves. ### 3. Damp patches on internal walls If you have persistent damp on internal walls — particularly on walls that face outward — and you cannot identify an obvious cause such as a leaking pipe, roof problem, or condensation, failing mortar joints may be allowing water to penetrate the wall. This is especially common in older properties where cement repointing has been used. Cement is far less breathable than lime mortar, so moisture that enters the wall cannot escape through the joints and migrates into the brickwork and internal plaster instead. ### 4. Spalling or flaking bricks Spalling is when the face of a brick breaks away, leaving a rough, pitted surface. It is caused by moisture freezing inside the brick — water gets in through failed mortar joints, saturates the brick, and then expands as it freezes in winter. Once a brick starts to spall, the damage is irreversible. The brick will need to be cut out and replaced. Catching failing mortar before it leads to spalling is far cheaper than replacing individual bricks. ### 5. White staining (efflorescence) Efflorescence is the white, powdery deposit that sometimes appears on brick surfaces. It is caused by soluble salts being carried to the surface by moisture as it evaporates from the wall. While efflorescence itself is not structurally harmful, it is a reliable indicator that moisture is moving through the wall — often through failed mortar joints. ### 6. Gaps or voids at the mortar-brick junction Look closely at where the mortar meets the brick face. If you can see a gap or shadow along the edge of the joint, the mortar has shrunk away from the brick. This creates a direct route for water to enter the wall and is a clear sign that repointing is needed. ### 7. Previous cement repointing on an older property If your home was built before 1920 and has been repointed with cement at some point — which is very common — this is itself a warning sign, even if the mortar looks intact. Cement mortar traps moisture in older brickwork and causes long-term damage that is not always visible until it is well advanced. If you are not sure whether your property has been repointed with cement, look at the colour and texture of the joints. Lime mortar tends to be off-white or cream with a sandy texture. Cement mortar is usually a harder, darker grey. ## What Causes Mortar to Fail? Mortar deteriorates for several reasons: **Age.** Even well-specified mortar has a finite lifespan. Lime mortar in a well-maintained property can last 50–100 years, but it will eventually need replacing. **Weathering.** Exposed elevations — particularly north-facing walls and chimney stacks — are subject to more rain and frost than sheltered areas, and mortar deteriorates faster as a result. **Incompatible materials.** Using cement mortar on older brickwork is one of the most common causes of premature failure. The mismatch in hardness and breathability causes both the mortar and the bricks to deteriorate faster than they should. **Poor original workmanship.** Mortar that was not properly mixed, applied too thin, or not allowed to cure correctly will fail earlier than it should. **Structural movement.** Subsidence, settlement, or movement in the building's foundations can cause mortar joints to crack. If you are seeing widespread cracking across multiple elevations, it is worth having the building assessed by a structural engineer as well as a brickwork specialist. ## What to Do If You Spot a Problem If you have identified one or more of the signs above, the next step is to have the brickwork assessed by a specialist. A good contractor will: - Identify the extent of the failing mortar - Assess whether the existing mortar is lime or cement - Recommend the correct mortar specification for your property - Give you a clear, honest quote for the work For older properties, it is important to use a contractor who understands lime mortar and can specify the correct mix. Using the wrong mortar — even with good intentions — can make the problem worse. ## How Repointing Is Carried Out Proper repointing involves carefully raking out the old mortar to a depth of 15–20mm using hand tools or an angle grinder with a mortar raking disc. The key word is carefully — the brick faces must not be damaged during this process. The new mortar is then mixed to the correct specification, applied in lifts, and tooled to match the original joint profile. For lime mortar work, the curing process is slower than cement and the work needs to be protected from frost and direct sun while it cures. The result, done correctly, is brickwork that is weathertight, breathable, and protected for the next 30–50 years. ## Acting Early Saves Money The cost of repointing a single elevation is a fraction of the cost of replacing spalled bricks, treating penetrating damp, or repairing internal plaster damage caused by a saturated wall. If you have spotted any of the warning signs in this guide, it is worth getting the brickwork looked at sooner rather than later. At G.P Brickwork Solutions, Glen Cook carries out every assessment and repointing job personally across Essex and London. If you are concerned about your brickwork, [get in touch for a free site visit and quote](/lp/lime-mortar-repointing-essex?utm_source=blog-aab&utm_medium=blog&utm_campaign=cmp_htF_YSGzA41YeiQQ7MG3xgij2uVmfd-WojO3CxPrIHM&utm_content=act_Nwli-JIiHUFRpsxvuk_wqK1WtBIZ_8L0flLgo9h5nKM&utm_term=topic_brickwork-repointing) — no obligation, and Glen will give you a straight answer about what needs doing and what does not.