EVERYTHING You Need To Know About Cleaning Composite Decking

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

Compared to wooden decking, which requires extensive care and maintenance to stay clean and to 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, be easy to clean, require little maintenance, and highly customizable in its designs and colors.

composite decking plus

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

Capped composite decking is usually referred to as simply “composite decking,” and we will be referring to the shortened version throughout 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 the winter season, you also need to remove snow and ice safely.

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

In this article, we cover everything you need to know and do to clean your composite deck and porch safely.  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)

Composite decking is engineered to be durable and low maintenance, and it is easily cleaned using everyday household items.  

And no, you don’t need to rent a pressure washer 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.  This ensures nothing gets in the way or damaged during the cleaning process.
  2. Sweep the floor with the broom to remove any loose debris.  Before you apply water, make sure all loose dirt and leaves are removed.
  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

Following this process should leave your deck spotless and clean!  When the floor is dry, replace the furniture and decor.

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


But what about stains or material not removed during this process?

If the stain or material is unusual, this cleaning method might not remove the stain.  If this happens, 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.  Not following their approved list of cleaners can damage your decking or void the warranty, so it is critical to follow their approved list.

caution not using approved cleaners

Cleaning Composite Decking Of Common Stains & Problems

Over time, your composite decking or porch will probably need to be cleaned from common problems such as mold, dirt, food and beverage stains, etc.

Here are the best ways to remove common problems from your deck:


Mildew and mold

While mildew and mold can infiltrate and ruin a wooden deck, it can’t damage a composite deck.  They look unsightly on your deck, but it won’t harm or ruin the composite structure.

The best way to clean mildew and mold from composite decking is by using the soap-and-water method mentioned in the previous chapter.


General debris

Leaves, small twigs, and other items often accumulate on a deck, especially if trees are nearby.  This general debris does not hurt the floor, but it can be a breeding ground for mold if it gets wet.

The best way to avoid this, and to keep your deck looking clean, is to sweep or blow off debris as necessary.


Dirt between floor grooves

The small grooves and spaces between the decking sometimes trap dirt and grime over time.  If this begins to build up, start with the soap-and-water method mentioned in chapter 1.

If this doesn’t remove the grime between the boards, then 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 manufacturers recommended PSI)

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


Food and beverage stains

Believe it or not, the vast majority of food and drink stains can be wiped away with a dry paper towel, including the 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 - on a wooden deck, these stains can be permanent, 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

Whether you have an outdoor kitchen or portable grill, many people enjoy cooking and preparing food on their deck and porch.  This means some oil or grease may occasionally end up on the deck floor.

Oil and grease should be removed quickly to avoid permanent staining.  Trex actually 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.  If done quickly, this removes the oil and grease without leaving a stain.



Depending on the plants close to your deck, you may see a thin coating of pollen on your deck.  Thankfully, pollen doesn’t cause long-term damage, but it should still be removed quickly.

The best way to get rid of pollen completely 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 - but 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.  This 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 small 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 should be enough to 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.  This helps prevent accidentally scoring or marking the surface by going against the grain or by crossing over 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

While you won’t use your deck regularly during the winter season, you probably still want to clean pathways to your backyard and make it safe to walk.

To remove snow and ice from your composite deck, you do want to make sure you 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 - if you have the right shovel!

Shovels with a metal cutting edge nick, cut, and damage the composite decking.

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

During light snows, you may not even need a shovel to clear your deck.  Many homeowners use a leaf blower or broom to clear light snow less than 1-2”.

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 and you have easy ground access, it may be tempting to use a walk-behind snow blower to remove the snow.

This is not a good idea! 

Like a metal-edged shovel, a snowblower cuts and damages the composite decking.  It is not worth the risk or damage on your beautiful deck!


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.

Remember - you don’t want to use any kind of metal edge or object to remove or break the ice.  While this method removes the ice, it also damages your deck.

Instead, you want to melt the ice.  What ice-melting agents are safe for composite decking?

Similar to 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 and our recommended solution.  This compound is highly effective at melting ice without damaging the composite surface.  It also does not hurt pets if accidentally ingested.

We do NOT recommend using traditional sodium chloride rock salt or sand.  These granules 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 you have, you may be tempted to apply a chemical cleaner to the stain to clean your deck.

This is never a recommended solution for cleaning 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 chemical cleaner.

Harsh chemicals, such as bleach, are NOT recommended on any composite surface!  These chemicals can eat away at the composite structure and leave permanent discolorations and damage.

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 make sure it is kept clean and free from unwanted stains and materials.

Thankfully, composite decking is easily cleaned 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 are looking to build the deck or porch of your dreams, then contact the team at Keystone Custom Decks 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 helps you design and create 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, take a look at our project gallery for more ideas on what you might want for your dream project.

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

Infographic on Cleaning Composite Decking