How do You Remove Mold From a Composite Deck?

Out of all decking materials available on the market, composite is the most low-maintenance of them all. However, just because you’ll have to spend several hours every year cleaning it, it doesn’t mean that you shouldn’t go through the process at all, especially since it might prompt other problems to occur, including mold growth.

So, if you noticed mold and fungi growing on your deck, you should remove them immediately. Fortunately, the entire maintenance process isn’t complex, nor difficult. In fact, you can clean the entire structure in six easy steps, so, without further ado, let’s take a look at what you’ll need to do:

Step 01: Gather Your Equipment

As we mentioned at the beginning of the article, a  is incredibly sturdy, long-lasting, and low-maintenance, which means that you could clean it by using products and equipment that you already have in your home. This means that you probably won’t have to spend any money on cleaning it.

For eliminating mold, fungi, and mildew from the floors, you’ll have to get some dish soap, a dense brush, a broom, gloves, old clothes, and, of course, a bucket of hot water. You should remember, it’s not recommended that you utilize a pressure washer on the structure, hence, you won’t have to look for a company that would lease you one.

Step 02: Remove Everything From The Floors

Once you’ve gathered all the items you’ll require, the next task is to remove everything from the platform, however, you should also do the same for the items surrounding it. So, no matter if you have furniture, decorations, or accessories on or around the structure, you should remove them.

Of course, doing this will guarantee that the items don’t get damaged, but more importantly, you could ensure that you don’t, for example, trip over something, fall down, and injure yourself while maintaining the moldy boards. Removing everything will also speed up the process and you can ensure that you don’t miss any moldy spots. This is a difficult task and if you don’t know what you are doing, you might damage the deck and have to modify it later on. According to, you can always call the company for a mold inspection first, before you decide to do anything. They will give you an estimate and tell you what needs to be done. After that it is up to you to leave it to the pros or tackle the issue by yourself.

Step 03: Get Sweeping!

By now, you’ve probably removed everything from and around the structure and this is where you’ll have to entirely sweep the boards with a broom in order to get the dirt, rubble, or mold out. If there are some leaves or dust stuck between the planks, get rid of them as well.

Keep in mind, before you add water to the boards, you must guarantee that you eliminated all dirt, mostly because it’ll speed up the maintenance process, but it could also help you see exactly where the mold is. If you’re sure that you cleaned everything properly, you can go on to the next step.

Step 04: Add Water + Soap

This is, perhaps, the simplest task in the entire maintenance process. Once you’re done seeping the boards, you should prepare a bucket of hot water and soak the surface. This will prepare the boards for the soap. When it comes to the solution, you should mix your dish soap with hot water.

The concentration will actually depend on you, but a lot of experts such as, suggest that you prepare a concentration that is similar to how you wash your dishes in your kitchen. If you add too much of it, it won’t damage the boards, but it’ll be more difficult to rinse later on.

Step 05: Scrub Away!

Scrubbing the boards will take the longest, mostly because you’ll want to ensure that you entirely eliminate the mold. For this step, you can simply place the tough brush into the container, and begin rubbing the boards. It’s a messy process, which is why you’ll want to wear old clothes and gloves.

Rub the whole surface properly with the solution you’ve prepared, and don’t forget, you’ll need to apply pressure to it in order to eliminate persistent mildew, dust, and filth. You could utilize a small brush or a toothbrush to ensure that you get rid of any mold between the planks.

Step 06: Rinse it + Place Back Your Furniture

The last thing you’ll have to do is to rinse the solution and dirt from your composite boards. Although you could do this by filling a bucket and rinsing the boards, it’ll take longer, which is why you may want to use a gardening hose – which will ensure that you remove any leftover soap that can be slippery.

Once you’re done, you should leave it for 30 minutes or a little bit longer so that the surfaces get dry. After that, you can slowly start returning your furniture, decorations, and accessories to your deck, and finally, you should sit back and enjoy your neat and mold-free composite deck.

FAQ: Answered

Before we conclude this article, there are a few frequently asked questions worth answering. For starters, if there are any food or beverage stains, you could simply and quickly wipe them away by using a wet wipe, including persistent stains such as the ones from red wine. However, if this doesn’t work, you should repeat our guide from above since this will definitely remove them.

It’s worth mentioning that, although it’s possible for you to utilize a pressure washer to quickly wash the structure, you should be extra careful with it since if you aren’t, you could end up damaging the boards. If you do opt for this method, you should utilize a fan tip on the washer since it’ll ensure that the spray isn’t too strong.

Additionally, you should never, I repeat, never pass 1.500 PSI when utilizing a pressure washer on the surface. If you do go above it, you’ll end up damaging the floor by leaving little cuts on it. The small cuts won’t compromise the security structure, but it won’t look as beautiful as before.


Although most people think that cleaning a composite deck is difficult, it isn’t. In fact, it’s extremely easy and will only require several hours every year for you to ensure that it is mold-free. Keep in mind, if you don’t want to go through the entire maintenance process, you could always hire a professional that’ll help you.

Now that you know exactly what you need to do to keep your deck spotless – and what you should definitely avoid doing – you might want to return to the beginning of our ho-to guide and start with the first task we mentioned – which is gathering all the equipment you’ll need.

Ricardo is a freelance writer specialized in politics. He is with from the beginning and helps it grow. Email: richardorland4[at]