how to clean composite decking, Composite Decking: How to Clean a Composite Deck

Composite Decking: How to Clean a Composite Deck

Composite decks are much easier to clean than many other decking options. Solid wood decks require extensive maintenance and care, while composite materials only need a fraction of the attention.

However, the reduced need for maintenance doesn’t mean you can leave these decks unattended. Let’s go over everything you need to know about how to clean a composite deck.

Why Are Composite Decks Easier to Clean?

Composite decks were made to provide homeowners with a low-maintenance option compared to traditional lumber decks. They’re made with a combination of vinyl/plastic and wood, coated with a vinyl treatment.

The amount of wood varies depending on the type of composite decking, with many products having anywhere between 40-70% wood. Antifungal chemicals and preservatives help to treat and protect wood materials from rot.

The combination of wood and vinyl makes composite decks more durable and easier to clean than decks made from wood alone. They still need some maintenance to stay looking beautiful and inviting, but fortunately, you can clean them just by using tools you have around the house.

Bonus: Click here to read our round-up of the best composite decking brands.

Cleaning Tools

Luckily, cleaning a composite deck doesn’t require any specialized tools. Odds are that you already own all the items you need to clean your composite deck properly.

You’ll need to gather these tools from around the house:

  • Broom
  • Bucket of warm water
  • Bucket of soapy water (you can buy special composite deck cleaner or just use dish soap)
  • Deck brush (make sure the bristles are on the softer side)
  • Hose

The Composite Deck Cleaning Process

There are six basic steps to cleaning a composite deck.

  1. Clear your entire deck of any furniture or objects that would get in the way of the cleaning process.
  2. Use the broom to sweep the entire area and remove any leaves, debris, and excess dirt.
  3. Spread warm water over the deck to get it ready for soap. Don’t worry about wetting every single inch; just spread it out the best you can.
  4. Mix soap and warm water, similar to the ratio you might use to wash your dishes.
  5. Dip the deck brush into the bucket of soapy water and start scrubbing your deck. Don’t be afraid to apply significant pressure to clear away as much dirt as possible—composite is hardy and can take it.
  6. Once you’ve scrubbed the deck, take a hose and rinse away all the soapy water. The sun will take care of the drying part.

What NOT to Do

Composite is popular because it’s incredibly easy to maintain and can withstand a lot. That being said, there are a few considerations to keep in mind to keep your deck looking its best.

You should avoid industrial chemical cleaners because harsh substances can eat away the composite material. Bleach is also not advisable because it can discolor the deck and ruin its appearance.

If you are unsure if a particular cleaning solution will work for your deck, you should check the manufacturer’s recommendations. You can generally find guidelines for care on the manufacturer’s website or in the materials that came with your purchase.

Finally, it may sound obvious, but it needs to be said: don’t clean your deck in the rain or snow. Wait for a bright and sunny day.

How to Clean Common Problem Substances

Decks that get a lot of traffic and exposure to the elements will typically get dirty easily. Let’s discuss some tactics for dealing with the most common sources of grime.

Mold and Mildew

Mold and mildew are not common issues for composite deck owners. Although vinyl caps help with protection, some decks still have organic wood materials at their core and are susceptible to rot.

You can prevent mold with the soap and water cleaning routine described above. Also, keep an eye out for cracked, torn, or broken deck boards throughout the year, as moisture can seep through and cause problems. Get these repaired right away.

Beverage and Food Stains

You can prevent food and beverage stains with a simple dry paper towel. The plastic in the composite prevents liquids from soaking in immediately. If this technique doesn’t do the trick, the soap and water method can finish the job.

If you’re struggling with stains despite thorough cleaning, check your composite manufacturer’s warranty to learn about getting a replacement. Many warranties cover stains from food and drinks.

Grease and Oil

Grease and oil should be blotted up as soon as possible. The longer these stains sit, the more likely they will sink in and become permanent.

Once you’ve soaked it up, use the water and soap method to clean up any residual grease or oil. Grease-cutting dish soap will work wonders.


Unfortunately, pollen tends to be a bit more stubborn to eliminate. Often, soap and water alone will not do the trick.

You may need to resort to power washing to remove pollen thoroughly. You may also consider moving pollen-producing flowers away from the deck, as well as trim the branches of trees that may drop pollen on the boards.

Keep reading below to learn our tips for power washing your composite deck.

Dirt & Debris

Having a composite deck is a great investment for your home, but it’s important to keep it free of dirt and debris.

By cleaning your composite deck on a regular basis, you’ll reduce the amount of time and effort needed for future cleanings. It’s quite easy to do but takes some elbow grease.

Remove all loose dirt and debris with a broom. Then clean your deck with a bucket of warm water and dish soap. Be sure to use a soft bristle brush to remove dirt and debris.

If you are using a more chemical-based cleaning product, be sure to wear gloves. Some homemade and chemical cleansers can cause skin irritation.  Always keep cleaning solutions out of the reach of children.

A low-maintenance routine as a renter or homeowner maintaining a composite deck include the following:

  • Sweep
  • Pour or spray warm soapy water
  • Use a soft bristle brush
  • Use a garden hose to rinse
  • Let the deck dry before applying any sealant

Be sure to check with your manufacturer for the best cleaning products, sealants, and seasonal maintenance requirements.

Issues With Concrete, Cement, Mortar, Or Stucco Dust

Protecting your deck from dust particles from concrete, cement, mortar, or stucco is essential.  Using warm water and dish soap is recommended. Put some pressure into scrubbing your deck to clear away the dust.

Covering your composite deck before working on your construction or remodeling project will help prevent dust and the build-up of other particles.

Hard Water Staining

Hard water is water with high amounts of mineral deposits such as calcium and magnesium. Spray your entire deck with soapy water and scrub with a soft bristle brush. Repeat this process if necessary until the hard water stains are gone.

If these unappealing hard water spots continue to be visible, it’s time to look into a solution. Try a water filtration that filters out the hard water before your next deck cleaning.

Chalk Lines

Colored chalk line discoloration tends to be permanent. As tempting as it may be to use harsh chemicals such as chlorine bleach, this is not a good idea.

You can attempt to wash the chalk lines with soap, warm water, and a soft bristle brush. If the chalk line remains on your composite deck, it is a possibility it’s a permanent chalk line.

Certain chalk line colors have been deemed impossible to remove such as red.

Check with your deck manufacturer for the best cleaning solution for chalk lines.

Tannins From Debris

The plant matter or debris that causes tannins can be removed. First, sweep your deck and use a water hose if you need to. Apply a brightener once your deck is dry.

Make sure to speak with your manufacturer about the best brand and option for applying a brightener to your composite deck. Brighteners contain oxalic acid which is known to remove tannins.

If you notice certain debris is seasonal, have a plan to do seasonal maintenance and cleaning to prevent tannin from staining your deck. Investing in a leaf blower might be a good idea.

Maintaining Railings

Cleaning and inspecting your railings often can be a big help in your deck maintenance routine. Check your railings after extreme and seasonal weather to ensure your deck is safe to use.

Cleaning your railings on your composite deck is a beautification process that only requires the following:

  • A garden hose
  • A bucket of soapy water
  • Start cleaning from the base of the railing

Using a mild soap is best. If you notice rust stains, hard stains, or grease on your railings, repeat your cleaning process. If you continue to see the stains, check your manufacturer’s guide for the best solution.

Seasonal cleaning will also prevent hard water stains and rust. Be prepared with a leaf blower for the fall and a plastic shovel for the winter. Spot-checking your composite deck monthly will also help maintain your deck.

Rubber Mats

When you first put down your welcome mat, it’s a good idea to be aware of any chemicals that could discolor or lighten the surface of your deck. Rubber-backed mats are often filled with substances that should not come into contact with your deck.

Mats with vinyl and latex backing can also leave marks on your deck. These mats or rugs with these types of backing materials can rust or stain your composite deck.

Be sure to read your manufacturer’s manual or contact them for more information regarding using rubber mats on your composite deck.

To make your composite deck less slippery, consider the below options:

  • Install anti-slip tape
  • Use anti-slip coating
  • Use anti-slip strips
  • Apply waterproof coating

Check with your manufacturer for the best brands and course of action to keep you and your family safe from slips and falls.

Job Site Storage

If you’re in the process of getting your composite deck built, be sure that you or the company cover any decking materials on site properly until they are installed. Dunnage bundles should be stacked properly and on a flat-level surface.

Never store dunnage directly on the ground, For select decking, 1” x 12” and 1” x 8” products, the bundle maximum height is 12 bundles.

There is a maximum stack height of 14 bundles of dunnage. The dunnage should line up vertically and be 8 inches from each other. The spacing should be approximately 2 ft on center.

How to Deal with Ice and Snow

You can shovel your composite deck like you would your sidewalk. However, you must also be careful when engaging in this activity.

Using a plastic shovel will be your best bet because metal shovels with a cutting edge can easily scratch composite decks. If you want to be especially careful following light snowfalls, you could use a broom or leaf blower to remove thin layers of snow.

If you are dealing with particularly stubborn ice, you may opt to use rock salt or calcium chloride to melt it before attempting to shovel. Rock salt is safe for use on modern composite decks, but make sure to wash or wipe it away as soon as it’s done its job.

How Often Do Composite Decks Need Cleaning?

There’s no hard and fast rule as to how often composite decks need cleaning. It’s more important to clean as needed to prevent stains from setting.

In general, try to clean your composite deck twice a year to take care of dirt and debris buildup. Many homeowners give their deck a good scrub once it’s warm enough to spend time outside and at the end of the outdoor season.

Can You Pressure Wash?

In general, yes. However, you need to be careful not to damage your composite deck when power or pressure washing.

Here are a few things to keep in mind if you want to go the pressure-washing route:

  • Always use a fan tip on your pressure washer. This will ensure that the water diffuses enough to not damage the deck.
  • Keep the pressure below 1,500 PSI, so you don’t risk denting the boards.
  • Don’t place the nozzle of the pressure washer too close to the surface of the deck. Always try to keep at least six inches of separation to avoid damaging the outer vinyl layer.
  • Follow the grain of the deck boards as you wash. Going against the grain leads to a greater chance of dents or damage.

Still Need Help? Contact Us!

If you have any additional questions about cleaning your composite deck, reach out to the experienced team at Decks & Docks. Contact us today, and a deck pro can help with any concerns you have.