Wall defects are one of the most common complaints in older housing stock, and also one of the most commonly mishandled. A crack gets filled, a stain gets painted over, and eighteen months later the same mark reappears in the same place. The cosmetic work wasn’t wrong — it was just applied to a symptom rather than a cause. Understanding which category a defect falls into determines whether a fix lasts a decade or a season.
Diagnose before you decide
Cracks fall broadly into two groups. Shrinkage and settlement cracks are usually hairline to 2mm, follow plaster joints or run around door and window openings, and stabilise once a building has finished moving. These are cosmetic. Structural cracks behave differently: they tend to be wider than 5mm, taper along their length, run diagonally through brickwork rather than just the plaster finish, and continue to open over time. Monitoring with a tell-tale gauge over three to six months is the standard way to tell the difference.
Damp needs the same discipline. Penetrating damp comes through the external envelope — failed pointing, blocked gutters, bridged cavities, defective flashing — and usually appears as a defined patch that worsens after rainfall. Condensation, by contrast, is a ventilation and heating problem, shows up on cold surfaces and in corners, and is often accompanied by black mould growth. Rising damp is genuinely rare and tends to be over-diagnosed; it presents as a tide mark below roughly one metre with salt deposits in the plaster. Treating one as the other wastes money reliably.
What actually holds up
Once the cause is dealt with, the covering method matters. Filler and paint work on stable hairline cracks and nothing else. Skim coating restores a flat surface but needs a sound substrate underneath and will telegraph any movement below it. Dot-and-dab plasterboard handles significant unevenness but creates a void that can trap moisture if the wall behind isn’t fully dry.
Panelling is the option most often overlooked for maintenance work, partly because it’s usually discussed in decorative terms. Modern interior wall panels are dimensionally stable, can be fitted to battens over an uneven substrate, and don’t require the wall behind to be perfectly flat or freshly plastered. Where they earn their place in a repair specification is on walls that are sound but visually poor — old patch repairs, mixed substrates, historic filler work, or surfaces that would need extensive skimming to bring back. Battened installation also leaves a service void that can accommodate cabling and, where appropriate, insulation.
The important caveat: panelling over a wall with an active moisture source is a delay, not a repair. Moisture will continue to migrate, and enclosing it usually makes the eventual damage worse. The sequence has to be source first, drying period second, covering third.
A workable rule of thumb
Cosmetic defects on stable walls can be covered. Active defects must be resolved before anything goes over them. Structural movement needs a structural engineer, not a decorator. Where walls are dry and stable but irretrievably uneven, mechanical covering methods — panelling or boarding on battens — generally outlast wet trades because they don’t depend on adhesion to a compromised surface.