Highly Breathable

Breathability is a term used within the building industry to describe how a substrate allows water molecules and air molecules to pass through it. If a surface has high breathability, this water vapour is able to freely pass through the surface ensuring it stays dry.

We took our products to a UKAS accredited laboratory to test all aspects of Emperor Paint products, including water resistance, durability, heat retention and breathability. To test the breathability of Emperor Paint products samples coated with each of our products were compared against untreated samples.

The results found that Emperor Paint products did not adversely affect the water vapour resistance of the substrates they were applied to. The SD value (breathability level) for Emperor Paint products was found to be below 0.03, well below the 0.5 which is often considered breathable by British Standards. This meant that the products passed the BS EN ISO 7783:2011 (water vapour diffusion) Quality Standard.

Unfortunately there is a large amount of misinformation when it comes to the breathability of masonry paints. The reality is standard masonry paints have poor breathability. This is because they are acrylic-based formulations, which do not allow surfaces to naturally breathe like they would do if they weren’t painted.

Even some paints that refer to themselves and breathable or microporous do not have enough breathability to prevent problems. Emperor Masonry Paint is highly breathable with an SD value of 0.03, meaning it is as breathable as limewash and does not adversely impact masonry’s ability to naturally breathe.

A masonry product that you may encounter are masonry sealers or brick sealers. These do as the name would suggest and seal the surface from the outside, preventing water entering the masonry but also preventing moisture escaping at the same time. This is because they often create a film on the surface of the masonry.

Emperor Masonry Creme absorbs into masonry and chemically bonds to the material instead of creating a film. This means it does not seal the pores of the masonry in any way and allows the masonry to breathe naturally. Emperor Masonry Creme has an SD value of 0.01, meaning like Emperor Masonry Paint it does not adversely impact the breathability of masonry surfaces.

Breathability is crucial for properties of any age, whether a listed building or a new-build house. The reason why breathability is mentioned as particularly important for older properties is that these structures generally have more moisture-related problems and the damage that can be caused from the build-up of moisture could be more significant. This said, for the long-term health of any masonry it is important to use a highly breathable product that will not trap moisture and allow your home to naturally breathe.

You do not need to remove any previous paint from a surface before applying Emperor Masonry Paint. While this previous paint is likely to have lower breathability, by applying Emperor Masorny Paint on to the previous paint, you help prevent moisture entering the wall and thus reduce the level of moisture that needs to escape.

Any moisture within the property will eventually breathe out of the wall, the process will just be slower than if you applied Emperor Masonry Paint to an unpainted wall.