How to Remove Rust Stains 

Rust stains on your siding or concrete can take a house from looking beautiful to looking rundown, even if the rest of your exterior is spotless. These orange or brown patches often show up around metal fixtures, outdoor furniture, or under overhanging areas. The good news? With the right methods, you can remove rust stains and restore your siding’s clean, bright appearance. You might be surprised to hear that the darkening under your roofline may also be partially caused by rust (or rather, by drifting environmental contaminates that include metal particles). We call this type "Fallout".

In this post, we’ll explain what causes rust stains, how to remove them, and when to call in the professionals (for example, us if you happen to live in the Niagara region of Ontario.

How to Remove Rust Stains from Siding

If the stains are mild, you can often handle the cleanup yourself. However, use caution! most effective cleaners are strong, and can hurt you or damage a variety of surfaces around your home. 

1. Start with a Gentle Wash

Begin by cleaning the area. If there is any organic growth present, see our post on cleaning with chlorine. 

If cleaning rust off of concrete, pressure wash the area instead of gently washing.

2. Get to Know Your Chemicals 

This isn't some idle warning meant to shrug off liability. The chemicals used to clean rust are generally acids (depending on the cleaning product, the ingredients  could include oxalic, hydrochloric, or muriatic acid). These may burn you, kill plants, etch glass, and hurt even the strongest materials.

You will need protective gear. I wear a high quality P100 respirator, eye protection, and heavy gloves. On the occasions where I have momentarily forgotten to affix my respirator, I've been reminded of why they are so important (by the burning in my chest).

This article isn't a substitute for proper training in handling acids. 

3. Apply a Rust-Removing Cleaner

You can use a rust remover specifically designed for the material you're working on, but the good ones are often quite expensive. My favorite (F9 BARC) comes out to $98.30 per gallon after tax. Despite the price tag, these are often just an acid that may or may not be buffered and watered down. My favorite alternative is Oxalic acid, which can be purchased in powder form from an online retailer, then mixed into hot water at a ratio of 1 cup of powder per 4 liters of water. This solution is sufficient for about 75% of the rust cleaning I do on siding. Rust spots on concrete often require something a bit stronger. 

Once you've chosen your cleaner you can

• Wet nearby delicate areas like windows and plants.

• Apply the cleaner with a pump up sprayer or spray bottle. You can "spot-treat" only the rusty parts of your siding as the oxalic acid shouldn't discolor your siding (though there are many combinations of cleaner/siding, so this isn't guaranteed).

• Let it sit for about 5–10 minutes but don't let it dry. If it is a hot day or the siding is in direct sunlight, you may need to re-apply to prevent drying.

• Scrub the area with a soft brush (this might leave streaks or spots if the siding is highly oxidized). My favorite siding brushes are made by Ettorre.

• Rinse thoroughly with clean water making sure to also rinse nearby objects that may have also gotten sprayed.

• Repeat if necessary

3b. If Treating Concrete Instead of Siding

• Wet nearby delicate areas like windows and plants.

• Apply the cleaner to the entire concrete slab/paver with a pump up sprayer or spray bottle. Do not "spot-treat" concrete as the stronger acids needed to pull rust from a porous material are likely to lighten the areas where they are applied. 

• Let the cleaner sit until dry.

• If rust is still visible, reapply the cleaner once your area is dry.

• Rinse off any nearby objects that may have been sprayed.
  
  

3. Preventing Rust Stains on Siding

Once your siding is clean, a few simple steps can help prevent rust from coming back:

• Replace or paint any rusting metal fixtures near your siding
  
  

• Keep gutters and downspouts in good condition to prevent metal runoff
  
  

• Store metal furniture away from exterior walls and off of concrete.
  
  

Schedule annual exterior cleanings to catch early signs of staining

4.Consider Using a Professional Soft Washing Company like Blue Wave Exterior Cleaning Inc.

If the rust stains are deep, widespread, or on upper stories of your home, it may be best to call a professional.
They can use a soft washing process that safely removes rust, algae, and other stains without damaging your siding. They offer a great alternative to you needing to climb ladders, work with dangerous chemicals, and learn as you go (possibly damaging parts of your house in the process).

Professional Rust Stain Removal in Niagara, Ontario

If you’ve tried cleaning rust stains and they keep coming back — or if you don’t want to risk damaging your siding — let the professionals handle it.

At Blue Wave Exterior Cleaning, we specialize in removing rust stains, algae, and other tough contaminants from all siding types. We proudly serve homeowners throughout Niagara Falls, St. Catharines, Welland, Fonthill, Port Colborne, Fort Erie, and the rest of the Niagara Peninsula.

Get a Free Quote Today

Contact Blue Wave Exterior Cleaning today for a free quote on siding cleaning or rust stain removal in the Niagara region.

Call us at (647) 212-6460
Email us at:  BlueWaveNiagara@gmail.com