Previously finished decking: Use Ronseal Decking Cleaner and Reviver to remove any dust, grease, oil, mildew, algae and other contaminants. Remove any loose, flaking or peeling coatings. To avoid patchiness, and if using a contrasting colour, make sure you remove all previous finishes using Ronseal Decking Stripper.
Very good value and quality, you will not find this Ron seal decking stain cheaper anywhere. It is the best money can buy and would strongly recommend to use it ...