How to Clean a Stained Deck

Decks can add beauty and functionality to your home, but they require regular upkeep for optimal performance. Cleaning it regularly is the best way to care for a wood deck.

Use liquid dish soap to cleanse your stained deck without harming its stain or surrounding plants. Liquid soap should be safe enough to use without harming either.

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Power Washing

Staining a deck can improve its aesthetic appeal and protect its wood, but prior to staining a stained deck it’s essential that it be thoroughly cleaned in order for new stain to adhere properly and soak into the wood grain. In addition, conducting a comprehensive inspection is important so as to make sure there are no cracks or splits that need repairing; any damaged wood should be addressed prior to beginning cleaning activities.

Power washers are an efficient way of clearing away dirt, grime, mildew and other impurities from wooden deck surfaces. To avoid damaging or etching them permanently, always follow manufacturer’s instructions carefully when using one. Professional cleaners use a sweeping motion with pivoting arms so as to ensure even cleaning as well as keeping an optimal distance away from surfaces in order to prevent splintering and other forms of damage from occurring.

Liquid dish soap is an effective, gentle cleanser designed for wood surfaces that is safe to use on a stained deck and won’t damage either the wood or stain. For stubborn stains caused by fungus and sap build-up, tannin stains cleaners (available at The Home Depot for $10) can remove those dark marks more effectively.

Before beginning power washing, first check for mill glaze, which indicates that your deck was once sealed with sealant. If there’s roughness to the touch then lightly sand or rub down with soft cloth; alternatively you could try oxygen bleach, an environmentally-friendly alternative to chlorine bleach that won’t harm wood and stained deck surfaces alike; just follow its label’s directions when mixing and applying.

Once the deck has been cleaned, use a garden hose to flush away any leftover cleaner and help its stain dry evenly. In addition, you may mist it to keep it damp during washing.


An inviting and well-utilized outdoor space in your home, a stained deck can also become one of the dirtiest surfaces. When used as an area for summer activities like alfresco cooking or parties, such as grill grease spots, food or drink spills, soot from firepits, tree sap, leaves and dirt collect. Over time this buildup of grime may leave an unsightly stain that leaves water damage and wood rot as its legacy.

Regular cleaning of the deck is key to keeping it looking its best, and using a pressure washer at low PSI settings (usually 500 to 600) can efficiently blast away most dirt and debris without stripping away its stain or damaging its wood substrate.

Brush and broom the deck regularly to remove debris that has settled onto its surface or been washed onto it from power washing, such as dirt, leaves, pine needles or twigs. Sweeping railings and stairs will help avoid moisture buildup that could result in mold or mildew growth.

While sweeping, it’s also wise to use a nonmetal scraper or paint scraper to eliminate bad spots of old stain from your wood surface. Although this task can be time consuming and tiresome, this step ensures that new stain applied will adhere and soak into it more fully than previously applied stains would. Sanding tools may then be needed to smooth rough areas for future staining jobs.

Green algae and moss stains are another cause of stained decks that require re-staining, often making removal difficult by hand and often reappearing after only short amounts of time. You can try scrubbing with oxygen bleach. If this fails, oxalic acid might work; however, its effectiveness against mold and mildew makes it less desirable; only use it if all other methods have failed first.


An alfresco season of cooking and entertaining can leave a deck greasy with grease from grill grease, saucey food or drink spills, candle wax smudges or light stains from liquid dish soap formulated for use on dishes, yet tough enough to scrub away grime. Light stains may be removed by using liquid dish soap suitable for dishes as a quick yet safe method; for more stubborn stains mix one cup of household bleach into four gallons of water and scrub the deck using a stiff-bridled nylon brush – remembering to rinse well to protect surrounding plants from damaging cleaning solutions that contain harmful plant life or the deck becomes permanently damaged during or post-cleanup!

If the surface of your deck has become stained with dark stains, an oxygen bleach cleaner or mildewcide may help lighten them by using either premixed formulas or concentrate. While using such cleaners can lighten staining quickly, these specific ones require longer waiting times than standard wood cleaners before being rinsed off with water.

Baking soda is an effective and safe solution to remove stain and deodorize a stained deck without harming surrounding plant life. Simply mix one cup of baking soda into one gallon of water and scrub your deck before rinsing clean with your hose nozzle.

Mineral oil can also be an effective and natural way to lift stains without damage to wood or stain. Simply apply a thin coat of mineral oil over the affected areas, allow it to soak in overnight and repeat as necessary in order to restore its beauty and enhance the deck’s aesthetics.

While you’re cleaning your stained deck, take this opportunity to inspect its wood for damage or rot. Check all joists, posts and railings for signs of water damage or warping; any soft or decayed wood should be replaced immediately.

Properly treated decks can last years if properly prepared before applying new stain, but without preparation it could fail to adhere or penetrate into the wood to provide necessary protection. By following these steps you’ll ensure your new stain looks great while lasting as long as possible, plus ensure future coats will apply evenly. It will also prevent moisture damage to the surface.


Before staining your deck, it must first be free from dirt and grit. A pressure washer can help, as long as you use low PSI and 40 or 60-degree nozzle – any more pressure than this could damage the wood! Alternatively, commercial deck cleaners or strong detergent solutions with stiff-bristled brushes could work similarly or vinegar may work too; just remember to rinse well afterwards using clean water!

If you choose a commercial deck cleaner, follow its directions exactly. A product containing degreasing agents that will break down oil- and latex coatings as well as solid or semitransparent stains may be included; bleaching agents will lighten your deck’s wood. Follow manufacturer’s recommendations regarding how much to apply and for how long before rinsing with clean water before letting the deck dry completely before sanding begins.

Chemical strippers are another effective option to use when it comes to stripping old stain from your deck. Make sure you follow the manufacturer’s instructions when applying a thick coat; allow it to absorb into the wood, and scrub with stiff-bristled scrub brush; once set in, scrub again using coarse stripping pad on power tool – but remember to wear a mask! This process should not be undertaken unsupervised as it could prove highly hazardous.

If your current coat of stain has flaked or peeling in several spots, stripping the entire deck is likely the best way to ensure an even surface with which you can apply new stain and prevent uneven coloring.

Use a deck brightener and conditioner diluted in water to remove any remaining grit from your deck surface, leaving it looking fresh while helping it take on your selected hue. Make sure to rinse it well afterwards to prevent discoloration or an unsightly ring around its perimeter; additionally, check that both ledgers and flashing are in good shape; any that have become damaged will require replacement with new ones.