How to Remove Rust Stains from Trex Decking

Trex decking has become a favorite among homeowners and marina lovers due to its durability and low-maintenance benefits. However, as resilient as Trex composite decking is, most decking is still vulnerable to occasional rust stains, especially if you have metal furniture or live in a humid environment.

Thankfully, removing rust stains might be easier than you think! Here’s a step-by-step guide for effective methods to remove rust from your Trex decking, restoring it to its pristine condition.

Why Do Rust Stains Occur on Trex Composite Decking?

Composite decking itself doesn’t rust. Trex decking, which carries both capped composite and standard composite deck materials, is built to resist moisture and stains. However, certain elements—like iron furniture, metal tools, or water rich in iron—can cause rust on your deck.

For example, if you have metal furniture on your deck all year round, over time, residue from rusting furniture can seep onto the deck where the feet rest during periods of rain. Once in contact with moisture, these items may leave behind rusty residue, creating unsightly stains.

Tools and Materials You’ll Need For Composite Surfaces

Trex offers general care guidelines but doesn’t specifically address rust.

To successfully remove rust stains from your Trex decking, here are some items we recommend considering:

• Mild dish soap
• Composite decking cleaner recommended by Trex*
• White vinegar
• Lemon juice
• Non-metallic brush that won’t scratch your deck.
• Water hose for rinsing
• Power washer for extreme staining
• Powdered oxygen cleaner (used sparingly and carefully for stubborn rust stains)
• Deck brightener

Effectively Remove Rust Stains: Here’s What NOT To Do 

When cleaning your decking surface, avoid harsh chemicals, including acetone, bleach, toilet bowl cleaner, and WD-40. While composite decking is made for harsh marine climates, products like these can destroy the surface of your deck and leave their own stains. Worse, they can leave your composite decking boards more susceptible to damage over time.

Step-by-Step Guide to Removing Rust Stains From Composite Decking

Capped composite decks like Trex decking should be cleaned with dish soap and water. This is because the cap is not typically made of the same composite as the rest of the board. Composite cleaners are best for regular composite boards. We will follow capped composite guidelines here as it’s extra gentle for cleaning your deck. 

Keep in mind that your Trex deck may not need all of these steps—once you’ve got your rust removed, rinse your deck gently and call it a day! If you are still dealing with stubborn rust stains, continue on to next steps.

Step 1: Prep and General Cleaning

Clear your area. Move furniture, plants, and other items away from the area with rust stains. Brush off debris using a non-metallic brush to gently remove surface dirt, leaves, and other unwanted materials. Then, hose down your deck, lightly spraying to remove loose particles that could scratch the deck during cleaning.

It is preferable not to use hard water to rinse your deck for rust stains since you’re trying to remove mineral deposits of iron and its oxidation and don’t want residue.

Step 2: Start by Applying a Mild Dish Soap Solution

Combine mild dish soap with water in a bucket. Dip the brush into the solution, then gently scrub the rust-stained area with a soft bristle brush. Avoid scrubbing too hard, as Trex decking can scratch if abrasive force is applied. After cleaning, rinse the soapy water off thoroughly with a hose to get rid of residual soap and loosened rust.

Step 3: Try White Vinegar or Lemon Juice

If the dish soap didn’t work, vinegar and lemon juice are mild acids that shouldn’t damage your decking boards during the cleaning process and can help remove stubborn rust stains. Mix a half-and-half solution of vinegar with water, spray it on the rust stain, and wait for about 10 minutes. Use a soft bristle brush to gently remove the loosened rust stain, then rinse (again, avoid hard water).

This process can be repeated for tough stains, and you can try mixing a 50/50 solution of lemon juice and water instead of vinegar. 

Step 4: Apply a Deck Brightener for Stubborn Stains

While the Trex manufacturer does not recommend a specific brand of deck brighter, these products are designed to revitalize your deck’s color, and they can help lift stubborn rust stains:

• Following the manufacturer’s instructions, apply the deck brightener to the stained area.
• Let it sit for 15–20 minutes to absorb.
• Rinse it off.

Step 5: Powdered Oxygen Cleaner

Oxygen-based laundry cleaners can be used sparingly for extremely tough rust stains. To avoid damaging your deck, test the cleaner in an inconspicuous area first before trying it on the stain in a visible area. Dampen the stain with water, apply a little powdered product to it with a soft-bristled brush, and then rinse.

Step 6: Pressure Washing a Capped Composite Surface

According to Trex’s composite deck care guidelines, use a pressure washer no greater than 3100 psi with a fan tip attachment and a soap dispenser. Spray your decking with soap, then gently scrub each deck board with a soft bristle brush. Keep the nozzle a safe distance from the decking surface (at least eight inches), and always spray in the same direction as the boards. Rinse well so dirty water doesn’t remain in the decking material and cause a film.

Preventing Future Rust Stains on a Composite Deck

Once you’ve removed the rust stains, you can take a few preventative measures to keep the appearance of your Trex decking looking great.

Use Furniture Pads

Add rubber mats or non-metallic furniture pads to metal patio furniture or metal planters. However, keep in mind that rubber-backed mats may contain substances that can sometimes discolor or lighten the decking surface. Give us a call or bring the mat into a local store if you’re unsure, and we can help you decide if that particular mat is a good idea.

Store Tools Safely

Keep metal tools off the deck or on a non-metallic mat.

Regular Maintenance

Rinse and clean your deck semi-annually to keep rust and other stains at bay. While capped composite requires slightly different care than what you’d do for standard composite decking, regular cleaning with soapy water to remove dirt and debris goes a long way. The good news is that Trex has minimal upkeep, so you can get away with cleaning twice a year if no buildup or stains are present.

Trex Transcend Capped Composite Decking

Trex Transcend® decking sets the gold standard for beauty and durability, perfect for any outdoor living space and standing up to years of heavy usage. With deep, rich colors and natural-looking wood grains, this composite decking is designed with advanced stain and mold resistance, protecting your deck from fading, staining, and scratching.

Transform Your Outdoor Spaces with Quality and Expertise From Decks & Docks!

Rust stains on Trex decking can be pesky, but with the right approach, they’re easy to remove and prevent. Remember to keep your deck in top condition with occasional cleanings, and avoid leaving metal objects exposed to moisture for long periods.

If you’re ready to start your decking project or need further assistance, contact us at Decks & Docks for expert guidance and high-quality Trex products. Our team of decking specialists is here to help you build and maintain your outdoor oasis!