What causes wall damage in a house?

Wall problems in a house often stem from moisture, structural movement, impact, or material degradation. Rising damp, leaking gutters, or poor external rendering can allow water into masonry, weakening mortar and finishes. Thermal movement and settling can create cracks in plaster and brickwork. External impacts, pest activity, or corrosion of wall ties in cavity constructions also produce visible deterioration. Identifying the root cause—moisture source, load change, or material failure—is essential before repair so that fixes target the underlying issue rather than only cosmetic symptoms.

How to repair a cavity wall?

Cavity wall repair depends on the problem: bridging, insulation failure, or damaged wall ties. If cavities are bridged by debris or internal plaster, water can transfer across and cause damp patches; clearing the cavity and reinstating proper ventilation can help. Corroded wall ties need replacement using appropriate stainless-steel ties installed with resin or mechanical fixings. For cracked outer leaves, repointing, replacing damaged bricks, or applying breathable external render may be necessary. Repairs should preserve the cavity’s ability to drain and ventilate to prevent recurring moisture issues in the wall system.

How can insulation be improved during repair?

Repair work is an opportunity to address insulation deficiencies without major disruption. For cavity walls, installing suitable cavity insulation (subject to cavity width and condition) can improve thermal performance, reduce heat loss, and lower condensation risk if correctly specified. For solid walls, internal or external insulation options exist—each with trade-offs for space, finish, and vapor control. Ensure insulation materials are compatible with the wall substrate and moisture conditions; breathable systems are often preferable on older masonry to avoid trapping moisture within wall fabric.

Repairing walls in older buildings

Older buildings need careful assessment because original materials and detailing differ from modern standards. Lime-based mortars and breathable plasters are often best for historic masonry; cementitious repairs can trap moisture and accelerate decay. Structural timber frames or stone walls might require specialist consolidation, like selective masonry replacement or timber treatment, to retain historic fabric while addressing defects. When working on older houses or buildings, document the pattern of defects, consult conservation guidance where applicable, and choose repair methods that respect original materials and allow the wall to breathe and move naturally.

When to hire local services for wall repair

Simple cosmetic cracks and minor plaster repairs can be handled by a competent DIYer, but persistent damp, large structural cracks, leaning walls, or corroded wall ties warrant professional attention. Local services—structural surveyors, qualified builders, damp specialists, or conservation masons—can provide diagnostic tests (moisture mapping, tie checks) and design appropriate remedies. Obtain several assessments if the cause is unclear, and seek contractors with relevant experience for cavity wall work, insulation installation, and heritage repairs. Accurate diagnosis reduces the risk of recurring problems and ensures that repair methods suit the wall type and building context.

Conclusion

Effective wall repair combines careful diagnosis, appropriate materials, and workmanship that respects the wall’s construction and use. Address moisture sources first, select repair techniques compatible with the existing fabric—especially in older buildings—and consider upgrading insulation when practical to improve comfort and energy performance. For structural concerns or complex cavity and insulation interventions, professional assessment and skilled local services help ensure lasting results. Thoughtful repairs restore performance and prolong the life of the house or building without compromising its character.