Damp is one of the issues that concerns our clients the most. This is often due to conflicting advice given by non-conservation builders, whose repair methods frequently rely on covering, disguising, or blocking damp with barriers or chemicals. We do not advocate these approaches. Instead, we recommend methods that respect how old walls were originally built — designed to absorb and release moisture naturally — maintaining a healthy balance that shifts with the weather and seasons.
Older buildings were constructed with solid walls and no damp proof courses. These walls were intended to take moisture from rising damp, surface rainwater, or condensation, and then shed it externally by evaporation, and internally through small-scale air circulation.
Our approach to repairs follow these principles. Where walls have been repointed with hard cement mortars, we replace them with porous lime-and-aggregate rich mortars. If cement renders have been applied, we carefully remove and replace them with lime render.
Similarly, modern barrier paints prevent moisture evaporation; we use breathable, lime-based paints instead. Internal walls require the same approach: removing bitumen coatings, boarding, gypsum plasters, or modern paints, and replacing them with lime renders and breathable finishes that allow moisture to move freely.
For walls that have been sealed and unable to breathe for years, the drying process takes time. In very damp cases, this can mean 6–12 months before the wall returns to a healthy equilibrium. Patience is vital — given the right repairs and conditions, the building fabric will recover.
The choice of paints is also key. Today, most major paint suppliers produce breathable paints in a wide range of colours, so there is no need to compromise on design. Internally, colours are usually consistent, although they may appear darker at ground level in damper walls, before evening out as the wall dries with seasonal changes. Externally, colour tones can fluctuate after rain but return once the wall has dried. Removing modern, impermeable paints from brick or stone is a subject in itself, but suffice to say they act as barriers and may need careful attention.
Of course, there are many possible causes of damp beyond unsuitable mortars, plasters, renders and paints — leaking rainwater goods, ground levels, or structural defects, to name a few. These can only be identified through a detailed inspection and addressed as part of a tailored repair plan.
If you are dealing with damp in your property, or are considering purchasing an older building with suspected damp issues, we offer bespoke advice through our Consultation and Advice service.
