Ensure surface is completely dry & free from any loose or flaking material, grease, oil & any other contamination, Remove any fungal growth or mould with a suitable fungicidal wash prior to application, Shake thoroughly prior to use. Treat only dry walls & apply in dry weather conditions. Apply from top to bottom, When used on natural stone, marble or specific bricks test on an inconspicuous place first to ensure the look of the surface is not changed, Fortress Waterguard is designed as a top coat & it should not be necessary to re-treat for several years, Before any re-painting carry out a patch test in a small area first, Remove as much substance from brushes as possible before cleaning in warm water. Rinse & dry thoroughly