StainhandleR Roof & Deck Cleaner is a concentrate designed to clean asphalt shingles and cedar shake roofs, wood decks and fencing quickly and easily. Cleans aprox. 2,000 sq.ft./gal. It does not contain chlorine or bleach. Active ingredient is sodium hydroxide. Easy, quick spray-on and hose off application. Removes dirt, pollen, mildew and algae stains. Cleans stained cedar shake and asphalt shingle roofs. Cleans pine, cedar, redwood and cypress. StainhandleR Roof & Deck Cleaner makes stained and discolored roofs and decks look like new.