And… Breathe

In the world of traditional building and cob and lime restoration, breathability is everything.

It’s hard to believe that the wrong type of render can be so detrimental to a building’s integrity, but every day here in North Devon, where traditional houses and cottages are made of cob and stone, we see buildings that have been compromised by non-breathable render like concrete. The impact of modern, man made substrates on our old buildings can take a while to become apparent; damp patches, cracks and blown render tend to build up over years, with some builders offering low cost ‘sticking plasters’ like tanking or over-boarding that mask damage rather than fixing the problem. Ultimately however, if you have a house made of traditional cob, lime and stone that has been rendered in cement, problems are inevitable and the only real solution is to knock it all off and replace with breathable lime.

Why lime? Lime is a natural material that has been used for thousands of years. When applied correctly, it creates a solid, strong render that is simultaneously porous and flexible, which allows moisture to travel through the walls and escape, rather than being trapped within the walls with nowhere to go. It’s worth noting here that this goes for internal walls aswell; Lime render on exterior walls alone will allow moisture to travel freely and escape which is a positive in old buildings, but if your internal walls are plasterboard and gypsum, your interior damp issues will still likely remain as the moisture in the walls reaches the modern boarding, causing damp, mould or blown plaster. Natural lime plaster is alkaline, so it prevents mould and fungi from occurring in the first place.

Remember, breathability also extends to the paint you use. So many people spend thousands of pounds doing the right thing and having their house rendered in lime only to then paint it in a weather shield, non-porous paint. Your old house needs to breathe…everywhere! Utilising natural materials throughout is a must to eradicate damp, mould and cracking so be sure use a lime wash, natural paint when finishing your walls.

Natural lime render, plaster and lime paints are all inevitably more expensive than modern non-breathable cement, gypsum and chemical based paints but if you own an old building, utilising modern materials really is a false economy and will always be detrimental to the health of your home.

We are a small, family run business based in North Devon, with over ten years of experience working with cob, lime and stone. We know it can seem a complicated business, but traditional building techniques executed correctly really are a lot simpler, a lot more sustainable and a lot healthier for your home. We are always happy to talk through the process - click here to get in touch.