A basic recipe for homemade deck cleaner involves a gallon of water and a single cup of household bleach. This cleans and sanitizes the surface, and adding a single ounce of an ammonia-free household detergent to the mix can further enhance the stain removal properties of the cleaner.
Cleaners should don gloves before diluting the solution to protect hands from the potential hazards of working with bleach and carefully apply the solution using a sponge mop or scrubbing brush. Cleaning the deck of dirt and debris with a light rinse prior to application can deliver greater benefits, but cleaners should avoid using a power sprayer or pressure washer, which can strip away the deck seal and damage underlying wood or concrete. Pretreating deep stains with the solution may offer further benefits.
Never mix ammonia- and bleach-based cleaners. This releases harmful fumes that are not safe even for outdoor use. Some recipes for deck cleaners and treatments or seals may include ammonia or ammonia-based ingredients to help bring out the shine on the surface of the deck. These often include oxalic acid for added brightness and restoration of the natural color of wooden surfaces. Allow any bleach-based cleaning solutions to dry thoroughly before applying these treatments to avoid accidentally mixing the two cleaning agents.