How to Get Rid of Mildew on Vinyl Siding
- 1). Fill a bucket with one gallon of hot water. Add one-third cup trisodium phosphate and one qt. of chlorine bleach.
- 2). Wet down the stained siding with water from the garden hose.
- 3). Dip a stiff scrub brush into the cleaning solution. If the mildew stains are up high on the house, use a long-handled scrub brush or a ladder to reach the spots.
- 4). Scrub the mildew stains from the siding using a horizontal motion. If you are cleaning the entire house, scrub from the top and work your way down. Work in sections of about 20 feet wide so the cleaning solution does not dry onto the surface. Rinse out the scrub brush frequently to avoid reapplying dirt and mildew to the siding.
- 5). Rinse off the siding with water from the garden hose. Make sure to rinse each section after you scrub to prevent streaking.
Source...