Removes toughest stains and waterproofers. Restores woods natural color and beauty. Removes dirt, algae, mildew and fungus stains. Use before waterproofing on: decks and fences, outdoor furniture, exterior wood, wood plastic composite decking. Use to remove solid stains for semi-transparent stains, or tinted and clear waterproofers. Approximately 150 sq. ft. per gallon depending on the condition and porosity of the wood.