The ACP biocidal surfactant is central to the process: It sanitises the surface for self cleansing and provides some durability to the works. It is a soapy concentrate with wide spectrum biocidal/antiseptic properties even at low concentrations.
Once diluted it is applied like soapy water with a brush, the foam takes the colour of the stains it is removing and is rinsed. Many surfaces do not require brushing. The ACP only uses the biocidal properties of the mix. This is often the case for roofs and green discolouration. The mix is sprayed to saturation and left to dry into the porosity of the masonry.
The ACP biocidal surfactant is applied on all surfaces without risk of discolouration, oxidation or other chemical damage. It is a high purity quaternary ammonium.
The ACP biocide is available in professional concentration of 40% and a general public one of 10%. It is the same substance. The 40% is diluted one part of concentrate to 39 parts of water to obtain a 1% solution. Likewise the 10% concentrate diluted one to 9 parts of water will give a 1% solution : The product is adapted to small intermittent applications.
Note for the building owner: The key to easy maintenance is to treat a live biofilm at the first appearance of dark fungal metabolites under coping stones and window sills in particular.