Wood Deck Cleaning and Brightening

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How to Clean and Brighten a Wood Deck

Wood decks require maintenance just like any other part of your home. This tutorial will walk you through the steps necessary for wood deck cleaning before refinishing. Not all deck refinishing projects require you go through this step. Your deck may just need to be power washed, but if your deck has been painted or you've used an opaque stain, you may have to go through this step.

Needed Tools and Materials

  • Eye protection (goggles)
  • Rubber gloves
  • Paint scraper
  • Stiff bristled brush (plastic bristles)
  • Plastic drop cloths (to protect plants)
  • Push broom
  • Deck cleaner

Watch Now: How to Pressure-Wash & Clean a Wood Deck

Inspect the Deck (Annually)

You should do an annual inspection on your deck looking for any loose boards or other structural components and also look for rotting wood. Telltale signs of rotting wood include discoloration, mold, and softness when pressed with a hard object such as a screwdriver. If any soft wood or dry rot is found, replace the piece.

Once you've looked everything over and the wood looks sound, proceed to the next step.

Prepare Wood Deck Surfaces for Stain

The first step is to prepare the wood surface for stain by removing loose surface finishes and paint if needed. If your deck does not have loose paint or opaque stain, you can skip this step. If your deck is painted and you want to repaint it you can also skip this step. This step is only if you have a painted or opaque stain and want to have a semi-transparent wood stained refinished surface.

  • Using a sharp paint scraper remove any loose solid stain, paint, or finish.
  • What does not come off by scraping will have to be removed by sanding.
  • For sealed film finishes such as varnish or paint, you'll need to strip this off with a chemical stripper. Make sure you have on your rubber gloves and eye protection when using a chemical stripper.
  • Apply the chemical stripper according to directions. Usually, you'll apply it in smaller sections and wait for it to work, then scrape the loosened finish away from the wood. For stubborn areas, you may have to apply the stripper a second time. You can also get in tight corners by using a putty knife. Rinse the stripper away as required by the instructions.

Types of Wood Deck Cleaners

There are a few types of deck cleaners or deck restorers on the market. They typically fall into three main types of cleaning base categories:

  • Chlorine bleach cleaners. Avoid these types of cleaners as they will harm the wood and leave an unnatural whitewash appearance. They are also known to cause fuzzing of the wood fibers.
  • Oxygen bleach cleaners. When mixed with water, these cleaners create hydrogen peroxide and a soda ash cleaning base. This is effective in removing mildew stains and graying caused by ultra-violet sun exposure on the wood and also effective in cleaning the wood of dirt and deposits. The wood returns to its original color after cleaning with this type of cleaner.
  • Oxalic-acid-based cleaners. These cleaners do nothing for removing mildew stains but are effective for removing tannin stains. Tannins are naturally occurring, water-soluble resins of a reddish-brown color found in wood such as redwood, cedar, and oak. Usually, this type of cleaner is used as a supplement to oxygen bleach cleaners if tannin staining is a problem.

Apply Wood Deck Cleaner

Once the wood is scraped and stripped if necessary and you've selected and purchased a cleaner, you're ready to begin:

  • Prepare the surrounding area and protect your shrubs and plants with a plastic drop cloth. It's also a good idea to hose down the surrounding area with water to immediately dilute any deck cleaner overspray.
  • Mix the deck cleaner according to directions and put on your eye protection and rubber gloves.
  • Spray the deck cleaner according to the manufacturer's instructions.
  • Don't try to cover the entire deck surface at one time. You'll want to work in sections and let the deck cleaner do its work.
  • Let the cleaner sit for some time as recommended by the manufacturer, usually between 10 and 20 minutes.
  • Once it has been working for the specified time, then using a hard-bristled push broom, scrub the deck clean. Work with the wood grain, not against it.
  • Rinse with water and repeat the process on the next section of the deck.