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Advantages of Keim Mineral Paints over conventional acrylic film forming coatings

Mineral Structure

Keim paints create a microcrystalline bond with the surface making the coating an integral part of the substrate. Conventional Masonry coatings are surface film forming coatings.


This microcrystalline bond allows moisture vapour to pass through the minute gaps between the particles within the substrate. Keim can achieve in excess of 96% of the original breathability of a surface once applied. Film forming coatings smother the entire surface and restrict the passage of moisture vapour, which can build up behind the coatings leading to paint flaking.


The microcrystalline bond formed by Keim paints creates a longer lasting coating. The paint becomes an integral part of the substrate – in Europe there are buildings painted with Keim after 100 years still in excellent condition. Film forming coatings typically do not have this kind of life span as the bonding is adhesive.

Colour Fast

As Keim paints are made from earth oxides pigments the colours do not fade, they are completely UV stable. There will be no discernible difference between buildings painted in the same colour at different times. Film forming coatings are not UV stable and therefore can show significant fading of colour over time.

Dirt Retention

Due to the presence of petrochemical additives, conventional film forming paint coatings have a negative electrostatic charge on their surface and therefore attract dust from the atmosphere. Keim paints do not have any such residual negative charge on their surface and therefore the rate at which dust accumulates is lower.

Algae & Fungal Growth

Keim Paints are inherently resistant to mould and fungal growth due to their high alkalinity, (pH is approximately 12.3), and will therefore provide long term resistance to mould and fungal growth. Keim paints are inorganic so there is nothing for algae to feed upon, preventing its growth and build up on the surfaces. Conventional film forming coatings are slightly more acidic than Keim paints, are closer to the middle of the PH scale and, being organic, provide a food source for fungus and algae spores.

Acid & Alkalis

The crystalline structure formed by Keim points is an insoluble silicate structure, similar to silica sand on a microscopic scale, and is highly resistant to both strong acids and strong alkalis.


Keim paints comprise a liquid potassium silicate paint binder with natural earth oxide pigments and natural mineral fillers, such as feldspar. They contain no solvents, are VOC free, odour free, harmless and have no toxic emissions. Keim products are carbon neutral. The majority of film forming paint coatings contain all or a combination of oil based additives, petrochemicals, hydrocarbons, acrylics etc.

Structural Defects

Due to the crystalline bond between Keim and the underlying substrate it takes on the same co-efficient of expansion as the mineral substrate, allowing existing or any possible future structural defects to be effectively monitored.

Light Reflectance

The crystal structure of Keim paints provides excellent light reflectance characteristics, which can satisfy lighting performance requirements in a wide variety of shades. Film forming coatings will often absorb a proportion of light rather than reflecting it, meaning they are not as light reflective. The crystalline structure of Keim paints reflects light as it hits the surface, the paint is a flat matt in appearance; resulting in Keim paints appearing crisper and brighter in all lighting and weather conditions.

Fire Retardant

Keim paints are inherently non-combustible and do not give off any toxic gases. Both the manufacturing process and the composition of the material create an incombustible product Conventional film forming coatings contain petrochemicals and acrylic which are more likely to burn in a fire.

Using Keim over surfaces previously painted with film forming coatings:

  • The use of Keim mineral paints will help to encapsulate the existing coatings, increasing the life span of the existing coatings.
  • Using Keim over conventional paints will give the benefits of light reflectance, UV stability, resistance to mould and fungal growth, acids and alkalis and lack of dirt retention.

Any previously applied film forming coatings will have restricted the breathability of the substrate, with subsequent applications of a further film forming coating further reducing the breathability With Keim paints less than 4% of the existing breathability of a surface is lost upon application.