Apply and walk away
Cleaning outdoor surfaces is essential to a professional job. Zinsser Spray Once is a no scrub, no rinse exterior stain remover that uses Mother Nature to do the heavy lifting. Spray Once removes stains from mould, mildew, moss and algae from fences, siding, patios, roofs, and other outdoor surfaces.
The bleach-free and non-acidic formula works with the wind, rain and moisture over time to remove unwanted stains. Spray Once is a concentrate that mixes up to five gallons and is applied with a pump sprayer directly on dry surfaces. Results are evident in the first 48 to 72 hours, however the cleaning power continues over the next two weeks. Zinsser by Rust-Oleum will get the job done the first time.