EVERYTHING You Need To Know About Cleaning Composite Decking

Capped composite decking is one of the most popular and efficient decking materials available on the market. 

At Keystone Custom Decks, we've discovered that one of the best things about capped composite decking is that, compared to wooden decking, which requires extensive care and maintenance to stay clean and look sharp, capped composite decking requires little maintenance or cleaning.

What makes it so easy to clean and maintain?

Capped composite decking is made of a precise blend of vinyl and wood and then surrounded with a vinyl coating or cap. It is engineered to repel dirt, so it is easy to clean, requires little maintenance, and is highly customizable in its designs and colors.

composite decking plus

In fact, if you love the look and style of a natural wood deck, you can achieve this look with composite decking and avoid maintenance! 

If you want to know more about the differences between composite and wood decking, read our blog on the subject.

Capped composite decking is usually called simply composite decking, and that's what we'll call it in this post. 

Whether your deck is brand new or a decade old, we know all decks get dirty - spilled food, possible mold, a drink stain, etc. During winter, you also need to safely remove snow and ice from your deck. 

So, what are the best practices for cleaning your composite deck and removing snow and ice?

In this article, we cover everything you need to know to clean your composite deck and porch safely and effectively. Feel free to read through the article or simply click the chapter relating to your cleaning question. 

Clean safely - and enjoy your clean composite deck when you are finished!

Table of Contents

  • suds icon
    1. How To Clean Composite Decking (in 6 easy steps)
  • cleaning products icon
    2. Clean Composite Decking of Common Problems
  • power wash icon
    3. How To Power Wash Composite Decking
  • snow icon
    4. Removing Snow & Ice from Composite Decking
  • not to icon
    5. How NOT to Clean Composite Decking
  • infographic icon
    6. Infographic on Cleaning Composite Decking

How To Clean Composite Decking (in 6 easy steps)

Engineered to be durable and low maintenance, composite decking is not hard to clean. You can easily clean it with everyday household items you will surely have on hand. 

And you don't need to rent a pressure washer in order to do a good job! 

Before you begin cleaning your Trex or TimberTech composite deck, make sure you have the following available:

  • A standard bottle of dish soap (Dawn is recommended) 
  • A nylon broom or brush of medium stiffness 
  • A bucket of warm water 


Once you have these items, follow these six simple steps to clean your deck or porch floor:

  1. Remove all the furniture, decor, and accessories. Removing these items ensures nothing gets damaged or gets in your way while you clean. 
  2. Sweep the floor with the broom to remove any loose debris. Before you apply water, make sure you remove all loose dirt and leaves. 
  3. Once the surface is swept, rinse the floor with warm water. This prepares the surface for the soap.
  4. Prepare a solution of warm water and dish soap. The concentration should be similar to how you wash dishes in a sink.  
  5. Dunk the brush head into the bucket, and start cleaning your deck! Scrub the whole floor with the soap/water solution, using good pressure to get into the grooves and clear away difficult dirt and grime.
  6. When you are finished carefully scrubbing the composite decking, rinse away the remainder of the soap and any leftover dirt. 
soap & water cleaning method

If you follow this process, your deck should soon be spotless! Once the floor is dry, you can replace all the furniture and deck accessories. 

To learn more about cleaning your floor with this method, please watch our video: 



But what about stains or materials that don't get removed during this process? 

If the stain or material is unusually tough, it may need some extra work. If you run into a stain you cannot clean off, check with the deck manufacturer to see their approved list of stronger cleaners. 

Composite deck manufacturers have an approved list of cleaners for their materials, and this approved list changes over time.  If you don't follow this list, you can damage your decking or void the warranty, so be sure you follow their approved list. 

caution not using approved cleaners

Cleaning Composite Decking Of Common Stains & Problems

Over time, you will probably need to clean dirt, food, beverage stains, and more from your composite decking. It's the nature of things we use that they get dirty. 

Here are the best ways to remove everyday messes that may end up on your deck: 

Mildew and mold

While mold and mildew cannot ruin a composite deck like they can a wooden deck, it does look unsightly and disgusting. Besides that, some types of mold and mildew can be a health hazard. 

The best way to clean mildew and mold from composite decking is using the soap-and-water method mentioned in the previous chapter. With some elbow grease, you shouldn't have too much trouble getting it off the smooth surfaces of composite decking. 

General debris

Leaves, small twigs, and other items often accumulate on a deck, especially if trees surround the deck. General debris such as leaves and twigs will not hurt your deck, but it can be a breeding ground for mold if it gets wet, and again, it doesn't look good. 

The best way to avoid this situation is to sweep your deck regularly and keep all that junk off the surface. That way, the mold doesn't have a chance to form. 

Dirt between floor grooves

The tiny grooves and spaces between the decking sometimes trap dirt and grime over time, and it can start to build up. If this happens, start with the soap-and-water method mentioned in Chapter 1. Some vigorous scrubbing on hands and knees may be needed, and a scrub brush can help get the dirt out of the cracks. 

If this doesn't remove the grime between the boards, you can use a pressure washer. To protect the decking as you wash it, make sure you do the following:

  • Use a fan tip 
  • Use no more than 1,500 PSI (or the manufacturer-recommended PSI)

For more tips and information on power washing a composite deck, see Chapter 3.

Food and beverage stains

Believe it or not, you can wipe away most food and drink stains on composite decking with a dry paper towel, including those dreaded red wine stains! 

If a paper towel doesn't clean the food or beverage stain from your deck, then the simple soap-and-water method from Chapter 1 should remove it.

This is where composite materials shine - these stains can be permanent on a wooden deck, but cleaning food and drink stains from a composite deck is really that easy!

the vast majority of food and drink stains

Oil and grease

Many people enjoy cooking and preparing food on their deck and porch, whether you have an outdoor kitchen or a small, portable grill. Occasionally, some oil or grease may end up on the deck floor. 

It's not the end of the world if you get oil on your composite deck, but you should remove oil and grease quickly to avoid permanent staining. The Trex company requires all food stains to be removed within seven days to maintain their stain warranty.

To clean oil and grease off composite decking, use the soap-and-water method or even just a wet rag with some soap for small spots. If done quickly, this removes the oil and grease without leaving a stain.


Depending on what plants grow close to your deck, you may see a thin pollen coating on your deck. Thankfully, pollen doesn't cause long-term damage, but you should still remove it quickly. 

The best way to completely remove pollen from composite decking is to power wash your deck. For the best practices on power washing your deck, see Chapter 3 below.

How To Power Wash Composite Decking

One of the most frequent maintenance questions we get at Keystone Custom Decks is the following: 

“Can I power wash (pressure wash) my composite deck or porch?” 

Our answer?

“Yes, you can - just be careful!”

When power washing composite decking, make sure you follow these four manufacturers and experience-backed rules:

  1. Use a fan tip on your pressure washer system. A fan tip ensures the spray is not concentrated enough to damage the deck’s surface.
  2. Never exceed 1,500 PSI when pressure washing your deck. You don’t want to damage or score (leave minor cuts) on your beautiful deck surface. Some manufacturers allow higher than 1,500 PSI, but always check their guidelines before using higher pressure.
  3. Keep a safe distance between the power washer and the deck surface. We recommend staying a minimum of 6” away from the surface. This distance is the sweet spot where you can remove any dirt without damaging the composite decking.
  4. Clean with the grain of the individual boards. When power washing your deck, direct the spray to match the grain. Spraying into the grain helps prevent accidentally scoring or marking the surface by going against the grain or crossing several boards.

For more information on power washing your deck, please click this link to watch our video.

when power washing your deck

How To Remove Snow & Ice From Composite Decking

You probably won't use your deck regularly during the winter season, but you may still want to clear pathways on it to make it safer to walk on. 

However, to remove snow and ice from your composite deck, use tools and products that won't damage the deck surface. 

Let's take a look at the safe ways to shovel your deck or use ice melt products.

Can you shovel snow off a composite deck?

Yes, you can shovel snow off composite decking without damaging the deck - just make sure you have the right shovel! 

Shovels with metal cutting edges may nick, cut, and damage the composite decking. You want to avoid them so you don't hurt your deck.  

To avoid damage, use a shovel with a plastic or rubber edge. This removes the snow safely without scraping or harming the deck's surface.

You may not even need a shovel to clear your deck during light snow. If the snow is less than 1-2", you may be able to simply sweep it off with a broom. 

to avoid scratching your deck

Can you use a snow blower on your deck?

Some homeowners have large decks or long walkways. If there is a lot of snow on your deck and you have easy ground access, using a walk-behind snow blower to remove the snow may be tempting. 

This is not a good idea! 

Like a metal-edged shovel, a snowblower cuts and damages the composite decking. Your beautiful deck is a valuable investment; you don't want to risk damaging it. 

Can you use ice melt or rock salt on composite decking?

Removing snow with a plastic shovel or leaf blower is pretty basic. A thin layer of ice or sleet on your deck is a different ballgame. But ice can be risky, so you definitely want to remove it as soon as possible before someone slips and hurts themself. 

Remember - you don't want to use any kind of metal edge or object to remove or break the ice. A hard metal edge could scratch or otherwise damage your deck. 

Instead, you want to melt the ice with a de-icing agent. What ice-melting agents are safe for composite decking?

Like stronger cleaning agents, you should always check the manufacturer's guidelines before using ice melt, especially if using a unique brand or chemical agent.

Calcium-chloride ice melts are usually safe for composite decking, which are our recommended solutions at Keystone. This compound is highly effective at melting ice without damaging the composite surface. It also does not hurt pets if they accidentally ingest it. 

We do NOT recommend using traditional sodium chloride rock salt or sand. These types of ice melt tend to leave unattractive and permanent marks on composite decking.

don't remove ice using a metal scraper

How NOT To Clean Your Composite Deck

Depending on the stain or cleaning issue, it may seem like a good idea to apply a chemical cleaner to your composite decking. 

We do not recommend applying harsh chemicals to a composite surface!

Remember - composite materials clean easier and better than the traditional wood deck, and using the soap-and-water method in Chapter 1 removes most of the dirt and stains.

However, if the soap-and-water cleaning doesn't remove a particular stain, don't default to a harsh chemical cleaner. You may just make the situation worse. 

Harsh chemicals like bleach are NOT recommended on any composite surface! These chemicals can eat away at the composite structure and leave permanent discolorations and damage. As we said, your deck is a valuable investment, and you don't want to ruin it that way! 

If you need to use a chemical solution to remove a spot or stain on your deck, check the decking manufacturer's website for their approved cleaning solutions.

if you need to use a chemical solution

Using an approved cleaning solution ensures two things:

  1. You won’t damage your composite decking.
  2. You won’t void any warranties.

While a composite deck is less maintenance and easier to clean than a traditional wooden deck, the homeowner still needs to know how to ensure it is clean and free from unwanted stains and materials. 

Thankfully, you can easily clean composite decking with the soap-and-water method or basic power washing.

most composite decking stains

If you have a wooden deck and want to replace it with composite decking, or if you want to build the deck or porch of your dreams, contact the Keystone Custom Decks team today!

As a custom deck builder in Lancaster County, we help you create your dream outdoor living space.  Whether it’s choosing the perfect color scheme or ideal features, our team enables you to design and build your dream backyard.  

We even offer a complimentary 3D rendering to help you visualize the final project before construction starts!

If you want to see what is possible for your home and backyard, look at our project gallery for more ideas on what you might want for your dream project.

We offer a wide variety of outdoor living services, including:

Contact our team today to start your journey - we would love to help your dreams become a reality!

Infographic on Cleaning Composite Decking