KEIM Mineral Paints can be applied over a variety of existing coatings including conventional acrylic and oil bound paints, limewash, earth and clay paints and of course existing mineral paint finishes.  The key to application over existing coatings is to ensure that the underlying material is sound, i.e. that the bond to the substrate underneath is strong and intact, as if the existing coatings come away from the surface (delaminate) then any applied material, no matter what it is, will also be removed. 

Whilst the breathability of the substrate will be determined by the existing coating, many of the other advantages of KEIM paints can still be achieved. This includes the colourfast and uv resistance of the finish, light reflectivity, durability, cleanliness and resistance to mould and fungal growth and most importantly any residual breathability of the original coating will be maintained. Acrylic coatings reduce the breathability by a certain value, continuing to apply the same coat will reduce the available moisture vapour permeability by the same factor for each new coating applied - quickly completely sealing the surface. KEIM Mineral Paints will only ever reduce the breathability on their initial application, further coats do not provide further restriction, and the initial percentage of breathability impeded is less then 4%. 

Whilst it is always an optimum specification to remove existing coatings, it is not always necessary in order to use and get a satisfactory performance out of an applied KEIM coating. 


As with all situations, if you would benefit from a site inspection of the surfaces in question to establish suitability for over painting, or for any other reason, please contact our sales team on 01952 231250 or who will be happy to provide dedicated proposals, support and advice. 


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