When it comes to painting walls of an old house, the type of finish is as important as choosing colours complementary to the era of the home
Whether you are painting exterior or interior walls, the most fun element is undoubtedly picking the colour, but this is not the only thing to consider when choosing paint for an older home. More important is selecting the type of paint, opting for one that is an appropriate finish for the surface to which it is being applied.
With old buildings, the ‘breathability’ of a paint is a crucial factor and it must allow moisture to escape from the substrate it covers. If an inappropriate, non-breathable paint is used, it is likely not only to peel, crack and blister, but also trap moisture, leading to dampness and decay of the underlying fabric.
The principal purpose of paint is to enhance and protect. Products such as limewash and lead-based paints have done this for centuries, working in harmony with buildings. Although lead paints are generally no longer available, other traditional finishes are. There are also some newer products that are well suited to old buildings, although, as with any paint, it is vital to understand the potential pros and cons before use.
How to repair
‘When dealing with a surface finish that has degraded, first establish why the paint has failed,’ advises Jon Mee of Earthborn. ‘There could be many reasons for this, from building defects that are causing water ingress to trapped moisture and salts, or “incorrect” paint usage – something that isn’t breathable and suitable for older buildings, trapping moisture in the walls. It is difficult to tell if the previous owners have painted, but flaking and bubbling paintwork are tell-tale signs.’
Michiel Brouns, of Brouns & Co, suggests starting with the assumption that some film-forming paints have been applied in the past four to five decades, so any paint that is failing or peeling is a modern ‘plastic’, petrochemical paint. ‘These paints are essentially always designed to keep moisture out but, obviously, no paint is ever going to do that. You will get hairline cracks so water gets in behind the paint and keeps the substrate wet.’
With these considerations in mind, Tom Balch, of Rose of Jericho, suggests buying from a reputable supplier that understands the way lime, breathability and old buildings work. ‘Discuss with them the specifics of your particular case, because every situation has its own unique challenges and differences.’
With old buildings, a good quality limewash is often ideal for exteriors, while clay paints may be used on interior walls. Linseed oil paints provide a traditional finish for joinery. Even so, whatever finish is considered, check the performance and suitability
