Wondering how to clean your composite decking the right way? In short, all it takes is a simple maintenance routine of sweeping off the debris, washing with a little water and liquid detergent, using a soft brush, and hosing off the deck four times every season, and giving it a scrub down at least once a season.
However, because we know you want to care for your investment long term, we're going to break down each of those steps as well as what you can do to make sure you maintain it and keep it in its best shape for many years to come.
You don't need any harsh chemicals or overly expensive equipment. You just need to be equipped with a few recommendations from our team that won't break the bank and will help you maintain your investment. At blokDEK, we've been building decks for years and specialize in composite decking and cedar decks. Because we want our customers to be able to enjoy their deck for a long time, this is the care plan we advise to everyone who purchases one of our decks.
Without further ado, below you will find the full routine, plus how to handle any stains you might cause, how to mitigate discoloration, plus some commonly asked questions from our own customers and how we direct them to ensure their composite deck stays clean and well maintained.
What Makes Composite Decking Different to Clean
blokDEK, and most quality composite decking, uses a full HDPE capped surface. HDPE stands for High-Density Polyethylene and is a high-impact resistant plastic polymer. Its long-lasting and weather-resistant features often make it a top wood alternative pick, even for sturdy wood such as that used in our cedar decking solutions. Composite decking is also a great solution for water-prone surfaces, as water permeability is negligible, thus spills will not be soaked up the way that wood naturally does.
While the composite cap is designed to be resistant to stain and discoloration, it is not 100% stain proof. Therefore, certain procedures should be followed to help prevent marks and severe stains. We will cover this more later.
Composite decking, including the ones we make at blokDEK, are engineered with a certain texture to mimic the look and style of a wood grain surface. While that helps the aesthetics, dirt and pollen can settle into the grain, which is exactly why regular washing (again, we recommend hosing off your deck four times every season and giving it a full scrub down at least once a season) is recommended. Because of the HDPE cap, you do want to take special care to not use an overly strong solvent, which we will get into next on the mechanics of how exactly to wash your composite decking.
How to Wash Composite Decking in 4 Simple Steps
After installing and making hundreds of decks, we have found that this simple yet effective routine is the best to maintain the composite deck. You don't need expensive equipment; you just need consistency. That last part is key. Keep in mind that you need to hose off your deck around four times every season, but do a full scrub down at least once a season. So if you are in a heavy snow area during the winter and you have covered your deck furniture or removed it for the season, this won't apply then. However, as soon as the snow melts and you are ready for the spring, summer, and fall seasons, you'll want to follow these four simple steps:
1. Clear Debris First
While you don't want to use any tools that are too abrasive, a leaf blower will work just fine here. Clear the deck of any furniture as much as you can and give it a good clearing. However, if you don't have a leaf blower, a soft-to-stiff bristle broom will work just fine. Make sure the bristles aren't too stiff and aren't made of metal. Natural fibers tend to work better so you don't scratch the surface.
2. Rinse With a Hose
Once the surface is clear of any dirt, leaves, and debris, you can wet the surface with plain water from a standard garden hose. A pressure washer can be used, but it needs to be done so carefully; we will get to that more later. A regular hose with an attachment will work just fine for clearing the surface of your deck of any extra dirt and debris.
3. Wash With Soapy Water
Avoiding anything too acidic, just opt for a simple dish detergent added to a bucket of warm water; this is the optimal composite deck cleaning solution. A few squirts of liquid dish soap and around a gallon of warm water will work just fine. Any kind of solvent or anything too abrasive when it comes to a soap choice will not work, as they are not compatible with the HDPE cap.
Next, taking a push broom that is soft to stiff-bristled, work the soapy liquid across the boards in the direction of the boards. This is vital, as going across will damage the surface of the boards and leave scratches.
4. Rinse Thoroughly
Finally, rinse off the soapy solution with water again when you have finished scrubbing the boards, making sure to check the corners and edges of your deck for any extra soap residue. Try to do this all on a sunny day to give your deck plenty of time to dry so you can add back your furniture and decor when it is completely dry.
How Often to Clean Your Composite Deck?
Hosing off your deck about four times per season, with a full scrub down at least once a season, is a solid, consistent rhythm for routine composite deck care. However, your environment does play a factor in this. If your deck is placed in an area that's under trees and receives a lot of pollen, sap, and foliage buildup, or if you are near the coast with heavy exposure to salt water, you are going to probably have to wash the deck more regularly.
It's probably a good idea to get in the rhythm of sweeping your deck regularly in between these routine washes. When it comes time to wash, this will make it much easier on you to prevent more build-up.
The important thing to note, though, is that maintenance of these composite decks is very easy. Other than light brushing and a light detergent wash down, there is not much you have to do. That is why so many people choose our composite decking when choosing a deck from our made-for-you options in our shop.
The Best Cleaning Solution for Composite Decking: What To Use, What to Avoid
As we recommended, the simplest and safest option to wash your composite deck is to use warm water with a little bit of liquid dish soap. There's not a specific brand we recommend. We just avoid using anything that is acidic, has bleach in it, and that is too abrasive. Dawn Dish Soap works perfectly fine!
However, there are ready-made composite deck cleaning solutions that are available to purchase, and they are fine to use. Sometimes our customers prefer these because they can be a little more environmentally friendly, depending on what you use, and tougher on stubborn buildup. Here is a deck cleaning solution that you can easily order on Amazon.
When it comes to what to avoid, the number one rule of thumb you want to keep in mind is to avoid anything acidic and too abrasive. Unfortunately, using white vinegar is a popular DIY suggestion, but it is not recommended. Over time, the harshness of its acidic nature can dull the look of the HDPE cap. It's also not really necessary, as the HDPE cap is engineered to resist staining.
Make sure to avoid solvents such as mineral spirits, alcohol, and gasoline, as these overly abrasive materials can harm the cap. Abrasive scouring pads and harsh degreasers can also harm the cap.
Can You Pressure Wash Composite Decking?
Yes, you can pressure wash your composite deck, but it needs to be done so carefully. The rule is to always stay under 1,500 PSI and to use a fan tip. If you use a narrow or a turbo nozzle, the water will be too pressurized and it will damage the surface of your deck. You can also use warm water with a little soap here as well.
To power wash your deck, stand a reasonable distance from the boards, approximately 1 to 2 feet, as you want to avoid too much pressure. The pressure washer is not necessary. It is an option if you have experience using it and do it safely, but the hose and brush method listed above works just as well.
How To Remove Stains From Composite Decking
While composite decking is stain-resistant, common dinner items and outdoor debris such as mustard, red wine, grease, and pollen will leave a mark if not promptly treated. With that being said, these need to be cleaned as soon as possible.
For general stains from mild debris, use the warm water and dish soap plus a soft-bristle brush method. Clean as you normally would with your routine cleaning method.
For stronger stains such as barbecue from dropped food, treat with warm water (that's not hot, that's important), and scrub with a stiffer brush on the spot. Repeat if necessary.
If you find tree sap, the best thing to do is to let it harden over time. It's not really an instant fix, but when it hardens, you can scrub it off as it starts to flake away. Pollen is more noticeable on lighter boards, and the best approach is really prevention here. Make sure you don't forego your regular washing during the season.
Preventing Wear & Mild Discolouration
An ounce of prevention truly is worth a pound of cure. The best way to maintain your deck for years to come is to prevent it from any damage in the future. To prevent grease when grilling, put a mat underneath your barbecue. This is the easiest way to avoid the most common source of staining your deck.
Do keep in mind that as the years progress, mild discoloration is normal for these composite decks, as it is for any outdoor surface or cosmetic finish. This is more noticeable on darker boards. However, to help prevent this and delay this process, you're going to want to rotate your decor. Your pots, rugs, and furniture should be moved into different positions from one season to the next so the surface weathers evenly. If items sit in the same spot for too long, it will create a visible difference.
Remember to keep in mind, though, that the best treatment for composite decking is simply consistent washing as listed above. With composite decks, you don't have to seal, stain, or refinish, which is a major advantage over their wooden counterparts.
A Deck That’s Built to Last
When it comes to a deck, a composite one is a solid choice. It's built to last and generally low maintenance. All you need is a quick hose-off a few times a season and a full scrub down once a season, and it will keep it looking good for decades.
At blokDEK, our modular HDPE cap system is engineered exactly for this kind of care. We’ve built our decks to eliminate the headaches from beginning to end when it comes to installation and also when it comes to their care.
If you're considering purchasing a composite deck for your outdoor space, learn more about options, how it works, and see some samples in our blokDEK online shop.