What Is Breathable Masonry Paint?

Brick wall showing damage

 

What is breathability?

 

Breathability refers to the free passage of water vapour through the pores of a surface. With many waterproof surfaces, it is crucial not to seal the surface completely due to a build-up of moisture.

 

Whether it is a waterproof jacket, or a breathable masonry paint such as Emperor Paint, allowing water vapour to travel from inside the surface to the external environment is paramount to its long-term performance.

 

This is often not effectively maintained with waterproofing treatments, especially for waterproof masonry paints for exterior walls.

 

Why is breathability important?

 

All acrylic masonry paints will allow a degree of moisture to enter a structure. Some waterproofing masonry paints & coatings successfully waterproof the surface of masonry by sealing the surface. However, while this does successfully repel water from the surface, this causes a number of things that can significantly damage your home.

 

If the paint or coating is not breathable, any moisture that is present within the house either before or since the masonry paint is applied is trapped. This can accentuate any previous damp problems or cause damp that previously was not present.

 

Deterioration of the brickwork and breakdown of the surface can also occur due to frost damage, as the water vapour undergoes a freeze-thaw cycle that can result in a failure in the integrity of the substrate. This freeze-thaw cycle expands moisture by roughly 9% each time, gradually enlarging any damage each time, which in turn allows more moisture to enter and ultimately worsen the condition of the brickwork.

 

Furthermore, the moisture that cannot escape through the pores of the building can become trapped under the paint, resulting in peeling and bubbling due to loss of adhesion.

 

This makes non-breathable masonry paints not suitable for any buildings, but especially many older buildings that were built with a solid wall construction.

 

These highly porous properties were often treated with non-breathable masonry paint in the hope that moisture would be prevented from soaking into the solid wall, which without a cavity wall would easily spread into the internal wall causing damp. These non-breathable masonry paints applied to these buildings acted like a sealant, blocking the pores and trapping moisture.

 

This can be catastrophic for older buildings, leading to significant deterioration in building integrity and causing irreparable damage. Due to some sealant products, it has been believed by some that waterproof masonry paints should not be applied to these buildings at all.

 

However, a clear distinction must be made between waterproof masonry sealants that call themselves a waterproof masonry paint and technologically advanced products that utilise nano technology to repel water, while maintaining the breathability in porous materials. 

 

To effectively protect older properties, the exterior masonry paint must have a low SD Value. An SD value is a way to measure a surfaces ability to resist water vapour in comparison to a metre of air. To be considered breathable, a masonry paint should have an SD value of 1 or lower. 


If a material does not have an SD value of 1 or lower, this will not sufficiently allow water vapour, which carries the moisture that can build up within building materials, to easily pass through the material. 

 

How can waterproof masonry paint be breathable?

 

In the case of a breathable masonry paint for exterior walls, the surface must be water repellent from the outside, but permeable to water vapour from the inside. This requires advanced and innovative technology such as the formulation developed by Emperor Paint.

 

It achieves this through the nano technology in the formulation bonding to the brick, rather than sealing the outside of the surface which is the case with many waterproofing masonry paints.

 

By forming a part of the material, it does not negatively affect the breathability. It lines the pours of the brick without sealing them completely, meaning paint repels water from outside while still allowing moisture from inside to escape.


This is in stark contrast to many traditional sealants. As previously discussed, all acrylic paints will allow a degree of water to enter them. This includes advanced formulations such as Emperor Paint. However while sealants are highly waterproof, they create a film on the surface that is not breathable. Once this moisture inevitably enters the material, it will continue to build until the surface fails. 

 

Emperor Paint's nano technology ultimately allows exterior walls to dry, reducingpenetrating damp and energy waste, as a large proportion of heating in homes with high levels of moisture is diverted in order to reduce the moisture. When moisture levels are reduced, the energy can directly heat your home quicker and for longer. 

 

This also reduces your energy bills and your household's carbon footprint.

 

A highly breathable masonry paint.png

 

What is the best breathable masonry paint? 

 

As we have discussed, applying a waterproof but breathable masonry paint to your exterior walls is crucial for long term performance.

 

After years of innovation, our technologically advanced waterproof masonry paints are the most effective products available. Our breathable masonry paint comes in two forms; a coloured masonry paint and a clear masonry cream

 

Both products have been verified by the Energy Saving Trust and certified by an independent, UKAS accredited laboratory to last at least 25 years of harsh weather conditions.

 

The results of the tests also demonstrated that both products:

 

  • Reduced water absorption of 96.3% (Masonry Creme) and 93.4% (Masonry Paint)
  • On average to keep walls 6°C warmer on averafe compared to not treated walls
  • Maintained excellent breathability with SD values of 0.56 (Masonry Creme) and 0.60 (Masonry Paint)

 

The untreated wall in the test was measured to have an SD value of 0.57. The Emperor Masonry Creme and Emperor Masonry Paint giving SD values of 0.56 and 0.60 respectively, demonstrating that they had little effect on the breathability of the brick.

 

This makes it a suitable and highly effective waterproof masonry paint for cavity wall and solid wall construction buildings alike. 

 

Waterproof Masonry Paint

 

Our coloured waterproof masonry paint is an advanced formulation for use on any exterior wall. Available in a range of popular colours such as cream, white & gardenia, Emperor Masonry Paint will ensure your home looks pristine for 25 years or more.

 

  • Waterproof
  • Easy to apply, two-coat paint
  • Highly breathable
  • Self-cleaning
  • Energy saving
  • Proven 25-year performance
  • Available in a range of popular exterior paint colours
  • Will never peel or flake
  • Reduces penetrating damp
  • Resistant to UV degradation
  • Minimises the effects of frost damage
  • Discourages green growth & discolouration
  • Verified by the Energy Saving Trust
 

Waterproof Masonry Creme

 

Our Masonry Creme creates a waterproof coating on exterior brick, concrete, stone and more that does not alter the appearance of your home. It offers invisible protection so that you can enjoy the natural beauty of your brickwork for years to come.

 

  • Waterproof
  • Easy to apply - takes just one-coat 
  • Highly breathable
  • Self-cleaning
  • Energy saving
  • Creates a thermal insulation barrier on exterior walls
  • Proven 25-year performance
  • Does not alter the appearance of brick
  • Reduces penetrating damp
  • Resistant to UV degradation
  • Minimises the effects of frost damage
  • Discourages green growth & discolouration
  • Verified by the Energy Saving Trust

Emperor Paint & Masonry Creme tubs

We hope that this has answered any questions you may have had regarding breathable masonry paint. Are you looking to waterproof your home and want advice on the best breathable masonry paint for you and how to apply it? Our team of experts are on hand to help you at every step of the process. Contact the team today by calling 0333 006 8880 or send them an email.

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