Surface preparation before decoration accounts for 75% of the total time. This recommendation for surface preparation is suitable for both interior and exterior decorating works. The surface to be painted must be dry and free from dust, oil stains, salts and other contaminants.

If the surface is contaminated with salts

Prior to applying decorating materials, the surfaces of concrete, bricks and render must be thoroughly washed with water in order to remove all salts. There are several types of salts that have a destructive effect on the construction. They include sulphates, nitrates, chlorides and carbonates. There are several ways how these salts end up on the building's structure:

- in the form of salt with building materials (bags of concrete, bricks)
- from other places (ground water, water spatter or melt water)
- during chemical reactions with harmful gases (sulphur dioxide from the air)
- incorrectly chosen building materials for the restoration (alkaline liquid soap, for material conservation)

A new brick or concrete wall is usually processed with 5% hydrochloric acid and then rinsed with water. Water soluble salts migrate to the surface and while the water evaporates, the salts remain. These salts push decorating materials away from the surface; thus, decorating materials begin to peal.

If the surface is contaminated with oil stains

A surface contaminated with oil stains must be cleaned mechanically. It is necessary to shave or clean it with a metal brush or a sand blasting cabinet until a sturdy surface is reached. Later it must be washed with clean water. If oil stains have not penetrated the surface deeply, it can be sanded with sandpaper No.60 or No.80.

If the surface is contaminated with microorganisms or mould

A surface affected by mould or fungus cannot be washed, cleaned mechanically or otherwise treated. By washing or scrubbing the surface, mould or microorganism pores are spread and can contaminate other surfaces.

Before starting to work inside, it is necessary to make sure that the premises are well ventilated and the windows are open in order to avoid gas concentration, which appears when a cleaner reacts with microorganisms. Generously apply cleaner STERILIS to the surface with a brush, roller or sprayer.

The cleaner must be evenly applied to the whole surface in order to prevent areas of low cleaner concentration, where a repeated development of mould fungus becomes possible. If the surface is sprayed, hold the sprayer 20 cm from the surface. Leave the surface for (12-24) hours. Repeat the procedure where necessary.

After the surface is treated with STERILIS, it can be cleaned mechanically. If mechanical cleaning of the surface reveals areas with mould or other microorganisms, it is advisable to repeat the procedure with the cleaner.

If the surface was previously painted

If the surface was previously painted, make sure that the old layer of paint is not chipped or pealed. If the old layer of paint is not chipped or pealed, the surface must be washed with water and soap, washing powder or 3% soda solution and rinsed with clean water. After washing, the surface must be roughened using sandpaper No.60 or No.80. If the old layer of paint is chipped or pealed, the surface must be shaved or cleaned with a metal brush or a sand blasting cabinet until a sturdy surface is reached. The surfaces previously painted with chalk or lime must be washed until no paint remains. Following such cleaning, the surface must be washed with 5% hydrochloric acid or an acetic acid solution and rinsed with water.

Filling cavities, tears and cracks

Cavities, pores and cracks might appear after cleaning and preparing a surface. We recommend filling or correcting them with the filler IGIS.T according to the product’s instructions.