Breathable Emulsion Paint for interior walls
Breathable Emulsion Paint for interior walls
Breathable paint is such a commonplace term these days with plenty of greenwashing confusing prospective customers all over the industry. There is such a massive sliding scale of what is ‘actually’ breathable, but you can rest assured that the paints listed below are some of the best around. Whether you need breathable paints for old houses, or modern, there is plenty of choice.
If we don’t have breathable paint, the moisture can build up behind the paint (due to most paint being made from plastic) which eventually destroys the plaster, which can cause no end of issues. Damp walls cause mould and mildew, which must be avoided.
Breathable paint for lime plaster: If painting over lime plaster, Auro 344 is ideal as it is a lime based paint, although Auro 555 is compatible if you want colours. Bare plaster? Use this plaster primer.
How is breathability measured?
Fundamentally, breathability is measured using an SD value, which is known also as “equivalent air layer thickness”. The lower the SD value, the more permeable the paint is for water vapour to have the ability to pass through. This is a good thing, we want moisture to be able to exit the walls (through the paint), as this stops mould and mildew growth.
Are clay paints breathable?
Clay paints are also very breathable and a common choice.
What is a good SD value?
Anything below 0.5 is great, and more than enough for most homes. This 0.5 Sd value means that the paint “has the same vapour resistance of 0.5 metres of still air”. SD values are put into classes, and SD Class 1 shows the highest level of breathability (SD value of less than 0.14m)
SD Classes of Breathability
SD Class 1 - Highly Breathable - 0 to 0.14m
SD Class 2 - Moderately Breathable - 0.14 to 0.5m
SD Class 3 - Limited Breathablity - 0.5 to 1.5m
SD Class 4 - Low Breathability - 1.5m+