Surfaces must be sound, clean, dry and free from all defective or poorly adhering material, dirt, grease or wax and be thoroughly rubbed down using a suitable abrasive paper and dusted off. It is important to ensure that your wall is smooth and even to obtain the best results from Dulux Pure.Treat areas affected by mould, fungi or algae with Dulux Fungicidal Wash (A980-19260). If after thorough preparation, surfaces remain powdery, seal with one coat of an appropriate Primer (see below). It should not be applied on areas where moisture reading (as measured by Protimeter) exceeds 17%. These wall should be left to dry further.