The Best Cleaners for Your Outdoor Deck

What to Use on a Dirty Deck

Some experts recommend that homeowners should clean their decks at least twice a year -- preferably in the spring and fall. The safest, most environmental way to clean a deck is to not clean it at all, eliminating the chance of toxic chemicals being introduced into the environment and water. Sure, you could raze the deck completely, getting rid of all of that moldy, mildewed wood, recycling it and making it someone else's problem, and then start all over again by building a new one. But that's not always possible, nor is it the best or most feasible choice.

So let's figure out how to clean that deck.

  • 01 of 07


    Clorox liquid bleach has many uses, including cleaning outdoor decks. Mike Mozart / Flickr / CC BY 2.0

    Again, it's not the most environmental choice, but chlorine does a good job of tackling standing water, mold and mildew (if you have a swimming pool, you get it). Read directions and labels, use gloves and masks, and only with proper ventilation.

  • 02 of 07

    Karcher Pressure or Power Washer

    Sun Joe pressure washer
    Courtesy of Amazon

    In case you've never noticed, some people just love their pressure washers. Crank it up and blast it with the pressure washer, and what a thrill it is to watch the paint peel off the facade of your house or the dirt melt from the fence between your house and the neighbor's. It's all that firefighter / action hero stuff re-enacted in your own yard.

    If you don't own a pressure washer or can't borrow one from a friend or neighbor, they can be rented from a local hardware store, usually by the day. Once you've read the instruction manual, start at the center of the deck and direct the spray to both ends, hitting all areas. This should be done prior to applying a cleaner or brightener.

    Top brands include:

    • Sun Joe (pictures)
    • Karcher
    • AR Blue Clean
    • Simpson
  • 03 of 07

    Karcher Deck and Driveway Cleaner

    Karcher T250 Hard Surface Cleaner
    Courtesy of Amazon

    Before you get too excited, the Karcher Deck and Driveway Cleaner is not a machine that will do the job for you, like a robotic pool cleaner. This attaches to a Karcher pressure washer and will save you time by cleaning an 11-inch-wide path with each pass. Other attributes:

    • It delivers streak-free cleaning by constantly keeping its two spray nozzles at a fixed height from the surface.
    • Two spray nozzles spin at a high speed, which cause the attachment to "hover" and also make it easy to maneuver.
    • It's compatible with vertical surfaces as well, such as walls, fences, siding, garage doors, etc.
  • 04 of 07

    Oxygen Bleach Cleaner

    DeckBrite wood cleaner
    Courtesy of Amazon

    Oxygen bleach products are supposed to be safer for the environment. They may not tackle stubborn mold and algae that has set into wood decks, but if used more frequently, that mildew and algae shouldn't build up quite so often.

    Pictured: Rust-Oleum three-pound jar Wolman Deckbrite wood cleaner and coating prep.

    Continue to 5 of 7 below.
  • 05 of 07

    Safer Moss and Algae Killer

    Safer Moss & Algae Killer
    Safer Moss & Algae Killer works on outdoor surfaces. Courtesy of Amazon

    Safer makes a product that lists its main ingredients as 40 percent potassium salts of fatty acids, which is supposed to be a more green and environmental way to clean your deck.

    Safer's Moss and Algae Killer and Surface Cleaner is made from naturally occurring, biodegradable fatty acids. This water-based product is non-corrosive to metals, contains no zinc or iron, and is non-staining on most surfaces. Listed by the Organic Materials Review Institute, it will remove moss, algae and grime from decks, siding, walkways and other surfaces.

  • 06 of 07

    Spray-and-Forget-it Products

    Spray and Forget Deck and House Cleaner
    Courtesy of Amazon

    These products go by various names and have different ingredients, but the intention is more or less the same: to allow you to clean your deck without much effort. Some of the products purport to lift stubborn stains like moss, mildew and mold (the dreaded three Ms). They might repel rain and snow for up to a year. Some claim to be approved by the Environmental Protection Agency (EPA) and might be made of biodegradable ingredients that supposedly won't harm the environment.

    A few of these products include:

    • Wet and Forget
    • Spray and Forget
    • Moldex by EnviroCare
    • Bayer 2-in-1 Moss & Algae Killer Ready-to-Spray
  • 07 of 07

    Tri Sodium Phosphate or TSP

    TSP cleaner -- trisodium phosphate -- has many uses.
    Courtesy of Amazon

    TSP, or trisodium phosphate, is a powder-based cleaner that is one of the best at killing mold and mildew. However, TSP is not considered an especially green choice, and has all kinds of precautions on the back of its box. But if the deck has not been cleaned in a long time and algae is visible, it may have to


    be used, with care and caution. It's better to maintain the deck more often, including sweeping, rather than leaving it so that it has to be treated with something strong.