How To Remove Rust Stains From Composite Decking


One of the greatest things about composite decking is that it’s designed to be easy to maintain. Unlike with wood, you shouldn’t have to spend your summers applying sealants or replacing irreparably stained boards.

That’s not to say that composite decking won’t get dirty, however. It will accumulate dirt on occasion, and sometimes you might even experience issues such as rust stains. While composite decking is incredibly resistant to staining — which is another reason people prefer it to wood — stains can still happen if the planks are exposed to rust for too long.

This is most common when you’re using metal furniture that stays on the deck year-round. With time and rain, residue from rusting furniture can seep into the deck. Then when you move the furniture, you may find rust stains where the feet were resting.

Since you won’t want those stains to mar your beautiful deck, we’ve created this guide to help you remove rust stains from composite deck boards.

What Not to Do

You’ll see all kinds of advice online about how to remove rust stains from composite decking — but be careful about which tidbits to use.

In general, avoid cleaning your deck with harsh chemicals. These include bleach, toilet bowl cleaner and WD-40. These products can leave stains of their own, from bright patches to blue spots to bleach marks. Even worse, they can etch the surface of the decking, which can leave them more susceptible to damage over time.

Start With Dish Soap and Water

Because composite decking is resistant to stains, you’ll often find that the stain isn’t a stain at all — just residue sitting on the surface of the material. If you find a rust stain, use some dish soap, water and a scrubber. If the rust stain comes up, rinse the suds away and enjoy the results.

Try Vinegar or Lemon Juice Mixed With Water

Vinegar and lemon juice are mild acids that won’t damage your decking boards, but they can help remove more stubborn rust stains. Mix either of these in a half-and-half solution with water, then spray it on the stain and wait for about 10 minutes. Use a scrubbing pad to remove the rust stain, then rinse. You can repeat this process, if need be, for tough stains.

Powdered Oxygen Cleaner Can Help

If you use oxygen-based cleaners for your laundry, you can also try it on your deck to remove a rust stain. First, dampen the stain with a little water. Then, pour some of the powdered product onto the stain. Use a brush or scrubber to scrub at the stain, then rinse the cleaner away.

If All Else Fails, It’s Time to Power Wash the Deck

Power washing should be your last resort. If the water pressure is too high, you can do serious damage to the boards. Still, if the above methods aren’t working to remove a rust stain, then you can try it — but take care to follow the tips below.

  • Use a fan-tip nozzle — no jets, rotating nozzles or other type of nozzle. Fans help ensure that you’re not blasting a small spot with too much water pressure.
  • As you work, keep the nozzle a safe distance from the surface of the deck. Start with the nozzle about a foot away from the boards. If the water pressure isn’t too high, you may be able to move the nozzle as close as six inches from the deck’s surface.
  • Always spray in the same direction as the boards. This should help prevent scoring, since you’re moving with the grain rather than against it.
  • Adjust your power washer so that it won’t exceed 1,500 PSI to avoid scoring and damage to your deck.

In most cases, you shouldn’t have to work too hard to remove rust stains from decking made by NewTechWood. Our products are made to handle everything the elements can throw at them — and that includes rust stains. If you’d like to learn more about our composite decking, feel free to contact us — or check out these tips!