How to Clean and Seal a Composite Deck

Composite decks are a popular, dependable option for both homeowners and business owners. In addition to a great aesthetic, composite decks are characterized by excellent quality and durability. 

Composite decks are made of wood fibers and plastics – unlike traditional wooden decks. The hybrid nature of composite equates to less upkeep, but there is still a need for vigilant cleaning and sealing to ensure the deck lasts. 

At Teak and Deck, we work with property owners across Southern California. Clients who make it a point to regularly clean and seal can expect a 30-50-year lifespan from their composite deck.  

The good news is cleaning and sealing are very easy processes. In this piece, we want to explain the ins and outs of how to clean a composite deck to maximize its longevity. Here’s what you need to know. 

Understanding Your Composite Deck 

Owing to the makeup of wood fibers and plastics, composite decks are generally resistant to rot, warping, and splintering – making it an ideal choice for many properties. Some of the major benefits of choosing composite include:

• Great durability
• Lower maintenance 
• Excellent aesthetic
• Safety (no splinters!)
• Add value to the property

Despite all the benefits of composite, there are several key drawbacks, including:

• High initial costs
• Limited options for refinishing
• May expand/contract in fluctuating temperatures
• Difficult to recycle 

Composite decks require a certain standard of care to preserve the materials. Even though they are not vulnerable to the elements in the same way as wood, failing to perform proper upkeep may result in mold growth, staining, and fading. 

Proper cleaning and sealing are crucial to avoid these pitfalls.

Why Clean and Seal Composite Decks?

Sun, rain – and in some parts of Southern CA – snow can prematurely age your composite deck. While these decks resist the elements much better than traditional wood, you still have to be vigilant to avoid issues like mold growth and staining. 

This is why proactive care is so important to maintain the deck’s integrity. In addition to getting a good 30-50 years from composite, a regular cleaning and sealing routine preserves a polished aesthetic. 

Here’s where to start. 

Step 1: Get the Right Materials & Tools

We’ve got good news for you. A regular, proactive cleaning and sealing process for your composite deck can be done without a professional. However, if you neglect this procedure for long enough, you may need a pro to come down and mitigate issues with mold or structural integrity. 

For starters, here are the provisions you need:

• A composite deck cleaner specifically designed to address mildew and dirt without damaging the material. 
• A soft bristle brush
• High-quality sealant (to protect against UV rays and moisture)
• A paint roller or brush to apply the sealer evenly 
• Gloves and goggles

You should be able to find these items at your local hardware store. If you need recommendations, get in touch with us. We’ll be happy to provide some insight.

Step 2: Prepare the Deck 

Preparation is key when cleaning and sealing a composite deck. 

Start by removing all the furniture, plants, rugs, and any other items from the deck. Next, you need to remove all the debris – leaves, dirt, pine needles, etc. We recommend using a leaf blower or a Shop-Vac to do this. If you don’t have either of these, a broom will work – just be VERY thorough in your sweeping. The less debris on the deck, the better the seal. 

Third, do a comprehensive walk-around of the deck. Look for any issues with the structure or wear & tear. If there are any significant issues, it’s strongly recommended to deal with them before the cleaning and sealing process. 

Step 3: Clean & Dry the Deck

Now that the deck is completely cleared, it’s time to start the cleaning process. Using your composite deck cleaner and the soft-bristled brush, apply the cleaner to the deck and work it into the material. If there are any stained or moldy areas on the deck, spend extra time on them to get them out. 

Once the cleaning is complete, grab the hose and give the deck a rinse. 

But what about pressure washing? 

When you think of how to clean a composite deck, your first thought may be to get the power washer. Pressure washing is generally a quick solution to clean a deck, but it comes with some drawbacks. Most importantly, power washing can compromise the deck’s integrity if used improperly – due to the sheer force of the water on the material. 

If you’re dead set on using a power washer, we strongly recommend using a low-pressure setting. 

Step 4: Use a Suitable Deck Sealer

Now that the composite deck is completely cleaned, it’s time to seal it. 

The first thing you need to do is stir the sealant around to ensure there is a consistent blend. Next, use the paint roller to spread the sealant over the deck evenly. Take care to get the sealant into all the nooks and crannies. 

Different sealants have different drying times. Check your product’s directions and follow them accordingly. 

Sealing a composite deck is not necessarily difficult, but it may be tough to get it done comprehensively if you’re not an expert. If you want to avoid the risk, get in touch with a professional deck sealing service to make sure it’s done right the first time.

Step 5: Continue to Maintain the Deck

Cleaning and sealing a composite deck is the first line of defense against wear and tear. We recommend establishing a cleaning routine at least once per year. The more often you clean and seal your deck, the longer it will last. Be sure to avoid abrasive tools or harsh chemicals on your composite deck, as this can damage it over time. 

Now, there is more to the maintenance process than cleaning and sealing. It’s very important to conduct regular inspections – or have a professional deck maintenance service do it for you. These experts know how to spot the early signs of issues and take action before they spiral into bigger problems. 

Contact Professionals If Needed

A composite deck is a big investment – both in a home or a commercial property. These jobs typically range from $4.50 – $13 per square foot. Needless to say, composite decks are by no means cheap.

With proper maintenance and care, this can be a one-time investment. Working with decking professionals – like the team at Teak and Deck – can be instrumental in making sure your deck stands the test of time. These experts bring years of experience, specialized tools, and more to provide the very best care for your deck. 

Looking for Help? Contact Our Deck Restoration Team

Wrapping things up, composite decks are a very popular choice for more than just looks. The upkeep and cleaning process is much less cumbersome than their wooden counterparts. The most important thing is to stay on top of the cleaning process. 

If you have any questions about your composite deck or need some guidance, Teak and Deck is here for you. Even if you just need some pointers on how to clean a composite deck, our team is more than happy to answer your questions. 

Get in touch with us today. We serve the San Diego, Los Angeles, and Orange County area.