In English | Issue 2/2022
Patina finish and translucent colouring of concrete
Patina finish, glazing and Umbra colouring as well as translucent protective finishes are concrete dyeing methods which do not cover the concrete surface but keep the material feel visible.
The different types of treatment methods and the associated terminology are often confused with one another. The methods and presented in Finnish Concrete Association’s publication By40 – Betonirakenteiden pinnat ja luokitusohjeet (Concrete structure finishes and guidelines for classification).
The advantages of a translucent treatment method include, in addition to a toned finish, low maintenance needs and easy touch-ups. The nuanced finish has high wear resistance and ages beautifully.
Any non-uniform colouring or differences in the colour tones due to concrete repairs or casting defects can be rectified or patched up by means of a patina finish or translucent colouring methods.
Umbra patina colouring is a chemical method in which the ingredients react with cement and create a brownish colour on the hardened concrete surface based on different iron compounds. This method produces a brown, nuanced patina surface and the darkness of the colour can be adjusted.
Copper concrete is also a chemical dyeing method where copper powder is added in the concrete mix. After curing, an ammonium chloride solution is applied on the concrete surface. This turns the colour of the surface into tones of blue and turquoise.
Glaze dyeing (glaze coating) is implemented using a translucent silicate paint uniformly in one tone of colour. These will patch up any differences in colour tones due to concrete repairs or casting defects. The glaze coating is applied on the surface with a roller, brush, spray or sponge.
A glazed patina finish is produced with a translucent silicate paint using several tones of colour. The end result is a nuanced patina finish. This is a handicraft process and the paint is often applied using sponges.
A translucent protective finish refers to the use of a coloured protective coating on the surface. These products combine a concrete glaze with a protective surface coating. The products can be used to patch up differences in the colour finish of the concrete and to create a uniform glazed colour finish. There is a wide selection of available colours, including special colours and metallic colours.