Why do I still have marks after using 3 in 1 Mould Killer?
3 in 1 mould killer is designed to kill the existing mould and spores that will create new growth. Some moulds stain the area they grow on. 3 in 1 mould killer does not remove this stain but will help to ensure against further growth. To allow the area to be decorated I recommend coating with our Polycell Stain Stop and then painting the area.