Many properties suffer from damp, particularly older properties. To resolve this, the approach by some is to seal the building to make it waterproof, using non-breathable building materials and vinyl paints. Whilst this may offer some short-term relief, water will naturally find its way in (through tiny cracks in the walls for example, as the building moves). This water then has nowhere to go, and becomes trapped beneath the waterproof material and paint work, causing damp in the walls.
‘Breathability’ therefore refers to how easily water vapour can pass through a wall. A breathable wall is one that will take in moisture in the air then release it (as if the wall is breathing) without impacting on the fabric of the building. The type of paint you use is one factor that can affect the breathability of the walls.
One way to avoid damp in a building is to use breathable building materials, such as lime render or plaster, followed by a breathable – or ‘microporous’ – paint. Any paints that contain vinyl, acrylic, oils or plastics are not breathable and can trap moisture beneath the surface, causing mould build up or even blowing the paint off entirely.
Even if your property has not been built with breathable materials like lime, using a breathable paint can still contribute to a heathier environment. Claypaint is our most breathable paint, allowing moisture to easily flow through the surface, reducing condensation, mould and mildew.