How to Clean Composite Decking: Guide on Frequently Asked Questions

How to Clean Composite Decking: Guide on Frequently Asked Questions

How to clean composite decking

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Composite decking is a great choice for your outdoor space.

It doesn’t require any painting or staining and weed growth will be minimal due to its elevation above ground level, unlike timber decking which needs constant maintenance and treatment.

That being said, it still need soccasional cleaning and sometimes get stained with food. oil or other products.

Thinking of getting composite decking? This article will help you decide

If you have a composite deck, it is important to know how to clean it.

Composite decks are made up of different materials so they need special attention in the cleaning process.

If you don’t take care of your deck properly, the boards can discolour warp and split. In this blog post we will answer some frequently asked questions about composite decking that should help with the cleaning process.

How to clean composite decking

The best way to clean composite decking is with Sodium Bicarbonate based cleaners or washing up liquid and water. What you need to clean it will depend on what you are cleaning off and how old it is.

Capped and uncapped composite decking will have differing amounts of resistance to dirt with capped being able to stand up to harsher treatment.

Its best to clean your decking during summer when its likely at its dirtiest after heavier usage.

Here are 6 steps to give your decking a general clean, more specific questions are addressed below.

Step 1: You’ll want to move the furniture off your decking before you start. This might include chairs, tables, barbeque grills and potted plants- don’t try moving them around as it’ll make cleaning up more difficult than necessary!

Step 2: Break the area down into small sections so that you can wash and dry each section before the water gets a chance to dry and leave water marks. This is especially important in the summer when water evaporates faster.

Step 3: Use a sweeping brush to remove any dirt and dust that has accumulated on the decking. This will make it easier to wash off any stains or persistent dirt with a hose or bucket of water.

Step 4: Using washing up liquid or a designated composite decking cleaning substance, start at the top of your decking and wash towards you. Use a sponge or mop to apply the cleaning product then leave for a few minutes.

Step 5: Clean off the soap with a hose or bucket of water, making sure to get all the soap off of your decking.

Step 6: Using a dry towel or cloth , dry the decking. This will help to avoid any water marks or other damage that might be caused by wet composite boards

How to clean off food stains

Ketchup spilled on composite decking

Grab a dishcloth and soak it in warm water with detergent, then wrangle out any excess liquid by twisting or squeezing gently over sink so that you can apply to without making more mess than necessary.

Next scrub the area with a gentle circular motion, using the towel to soak up any stains.

Rinse with cold water and then dry off by blotting gently or use paper towels

*If your decking is really dirty you might want wear gloves for this part as some cleaners can irritate skin.*

Can I use a power washer to clean composite decking?

Man cleaning decking with a power washer

A power washer can take a lot of the hassle out of cleaning a deck, but it is generally not recommended to use one for cleaning the surface of wood or composite boards.

If you want get rid any dirt that’s been ground in over time then using your power washer might be worth considering on some spot areas such as where there are cracks and underneath furniture legs etc.

If you decide to use a power washer make sure to do it on a low setting and only use with the cold water. Test it on a small out of the way area first to make sure it is not going to cause any damage.

Kärcher Power Control High Pressure Washer

ProKleen Electric Pressure Power Washer 1600W

We recommend using a power washer that has no greater than 3100 psi and is equipped with soap dispenser.

This will produce the best clean for your surface while also removing dirt from dust or other types of debris.

Spray down the area first with water mixed in a solution of dishwashing liquid and scrub out any visible stains gently to avoid damaging wood fibers on the surface.

Rinse thoroughly after use by fanning spray over entire length at least 30cm away from material’s face until it runs clear.

Don’t linger too long as this can cause damage depending on how dirty/mildewy the boards are before cleaning process begins.

Can I use bleach to clean decking?

Chlorine bleach is a very corrosive chemical that can damage your decking.

It’s also not the best choice for removing mold, as it only works on non-porous surfaces and will strip away any protective coatings you have applied to capped composite decks like yours.

There is a good alternative called Oxygen bleach which is commonly used to clean clothing. Oxygen bleach is a milder chemical that doesn’t pose the same risks as chlorine bleach.

Sodasan | Oxygen Bleach

HLS Supplies Composite Decking Cleaner

To make your decking look like new, start by following the instructions in our Oxygen Bleaching guide.

Make sure you let it stay on for at least 10 minutes (ideally 30) and re-apply if necessary during that time period to guarantee optimal results!

Keep in mind though that if you deck is not dirty its best not to use any cleaners. Excessive cleaning can shorten the lifespan of your composite decking.

How to remove oil stains from composite decking

Oil stained decking

Oil stains can come from food, cooking or just from sitting unused for too long.

Composite decking is less porous than wood but still porous enough that oil stains can be problematic.

The number 1 tip to prevent oil stains is to clean them up as soon as they happen. Don’t give the oil time to seep into the composite decking and set.

Use a gentle household cleaner to remove the stain then wash away the cleaner with water.

If the stain is stubborn, use a scrubber pad or brush to remove it and then wash away any residue left behind.

If the oil stain is more persistent you can brush the area with a stiff brush in line with the wood gain. Use the Oxygen bleach mentioned above to speed up the process.

Are bird droppings harmful to composite decking?

Its inevitable that sometimes we will get bird droppings on top of our composite decking. They can usually be removed by scrubbing with a gentle household cleaner and water or soap.

Its unlikely that they will cause any damage to the decking if left but its still a good idea to get rid of them quickly with a soft scrubbing brush.

If you want to deter birds from pooping on your deck here are some great ideas to keep them away:

  1. Have reflective decorations which move in the wind
  2. Get an Owl or Bird of Prey decoy
  3. Clean up any food left on the decking

Defenders Wind-Action Owl

Raven Bird Repellent

How often should I clean my decking?

The answer to this question will vary depending on how often you use the decking and where the dirt is coming from. For moderate use we recommend cleaning the decking at least once a year.

If you use it more and if food is being spilled on top, then its best to clean it t the start and end of summer to prevent any long term damage.

In the case of more extreme dirt, such as oil or grease stains then its best to clean it immediately after they happen.

Final thoughts

Composite decking is expensive so you want to get the most from it.

The key things to do are to maintain and protect! Make sure not to use any techniques or chemicals which will damage the surface of your decking.

Yearly cleaning will be enough for most decking with normal usage, more than this is only recommended for heavier usage.

If you spill anything oily or heavily coloured then clean it up straight away, and use a bicarbonate (sodium) based cleaner to avoid any long term damage.

We hope you have enjoyed this article. If you are thinking about getting composite decking installed in the Preston area see our decking page. Thinking of building it yourself or want to know how its done? This will show you how to build your own composite decking.

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