Do you have unsightly rust stains on your concrete driveway or patio? You’re not the only one. In fact, it’s a common problem with any concrete surface. The good news is, there are lots of simple ways to remove the rust stains. This article will explain why rust stains appear in the first place and show you how to get rid of them.
What Causes Rust Stains on Concrete?
There are a few causes of rust stains on concrete. Firstly, if you have rusted metal items sitting on your driveway or patio and it rains, the rust could run off and stain the surface. Using fertilizers that contain iron and minerals in your yard can lead to rust spots too. In some cases, iron rich soil can even leave spots. However, the stains often come from within the concrete itself.
Most concrete areas are reinforced with a steel rebar, especially if they take a lot of weight, like a driveway. Over time, when small cracks form in the concrete, air and water will seep through and eventually reach the steel grid underneath. Once the rust forms, it can then travel back up to the surface of the concrete where it causes stains.
Are there Different Types of Rust Stains?
Yes, there are different types of rust stains depending on what the cause is. If the steel rebar inside the concrete rusts and the rust spreads onto the surface, you may notice cracked areas with rust around them. As the rebar rusts, it expands a lot, damaging the concrete and causing cracks.
This needs to be dealt with quickly because, as the cracks open, more water seeps in and the rusting gets worse, creating a vicious cycle. This is the most common type of rust stain, however, you may notice other types of stains on concrete.
If you have round spots of rust that protrude from the surface, often with a very dark spot in the middle, this is known as a rust pop out. This is caused by iron in the concrete itself. When the aggregate is mined, it often contains some iron-rich soft rock.
Most of this is separated but a small amount may remain in the concrete. This rock takes on water, causing it to swell and rust, so you end up with small popped out circular areas of rust.
Fertilizers or iron-rich soils will leave small rust spots scattered over the surface of the concrete. These are fairly easy to remove because they are only on the top of the concrete, not set into the concrete itself.
How to Remove Rust Stains from Concrete?
If you have rust stains on your concrete, don’t worry. There are a lot of different ways to remove them. If you have surface level stains, they can easily be cleaned with a dedicated rust remover or some great home remedies like lemon juice, for example.
When the stains are caused by a rusting rebar you can remove the rust and then use a sealer to stop the rust from seeping through, before fixing the cracks with concrete. However, if the steel skeleton is too rusted, you may need to replace it and re-lay the concrete. Rust pop outs can be removed and cleaned out with rust cleaners. Then, you just need to fill the holes with more concrete.
If you have concrete stains that you need to get rid of, there are all sorts of different cleaners and home remedies you can use. I’ve put together a list of the best ways to clean rust off your concrete.
1. Singerman Laboratories Rust Remover for Concrete
The Singerman Laboratories Rust Remover is one of the best products for easily getting rid of stains on any concrete surface. It comes in a powder form that you mix up with water until you get a nice gel consistency. That means that it is easily spread over vertical surfaces as well as flat areas.
Once you spread it over the affected areas, leave it for around 15 minutes and the stains should dissolve in front of your eyes. Then, simply rinse it off and your concrete looks as good as new.
There’s no need for any scrubbing with light stains, but if you have very heavy stains, a nylon brush might be necessary (wire brushes can damage the concrete). If the stains don’t come off the first time, apply another coat and it should be fine.
The other great thing about this product is that it’s non-toxic to plants. So, if you are trying to clean a patio area or driveway and you have a lawn and plants nearby, you don’t need to worry about the runoff.
Although this is one of the more expensive products on the market, it is worth the money because it’s easy to use, it works well, and it doesn’t contain the harsh chemicals that you find in other options.
2. Use Lemon Juice
Acids are great for dissolving rust stains, so lemon juice is an excellent home remedy. Don’t spend time juicing a hundred lemons though, just pick up a big bottle of Realemon Lemon Juice. It’s a great multipurpose cleaner to have on hand around the house.
To clean rust stains, wash the surface with soap and water first. This allows the lemon juice to penetrate the concrete as deeply as possible. Then, pour the undiluted lemon juice directly onto the stain, letting it soak into the pores of the concrete and adding more until you get a good coverage.
Let it sit for at least ten minutes, preferably more, and then scrub it off with a brush. Once the stain is removed, wash it with some warm water again.
Lemon juice is good for surface stains but if you have a lot of thick, flaky areas of rust, you may need a more robust cleaner.
3. Goof Off Rust Stain Remover
Goof Off Rust Stain Remover is a great multipurpose cleaner that tackles rust on a variety of surfaces, including concrete. It is essentially a strong acid, so it works in a similar way to lemon juice, but it’s much tougher.
You can use a sprayer to apply this stain remover, so it’s a quick and easy job. It is a spray gel, so it will stick to surfaces without running too much. You don’t need to dilute it either. Simply spray it on the stain and you’ll see it start fading right away. Continue spraying every now and again to keep it saturated until the stain disappears.
Then, rinse it off with some cold water and it will be completely gone. Goof Off still works on very deep rust stains, but you might need a few applications.
Goof Off is great for tough stains that can’t be tackled by home remedies, but bear in mind that it will burn up your plants. It’s quite a harsh acid, so make sure that you cover your lawn and plants with a tarp before you start spraying.
4. Use a Pressure Washer
A pressure washer is great for stripping away rust stains. If you have some light staining from metal items, fertilizer, or soil, you may be able to blast them off with a pressure washer. Concrete is durable, so you don’t need to worry too much about the pressure, just set it as high as it will go and see if the stains come out. However, if the stains are a bit deeper, pressure washing alone won’t cut it.
You need to use some lemon juice or a rust cleaner instead. Start by pressure washing the area to remove any loose rust on the surface. Then, apply your chosen cleaner and let it go to work. Once the stain has dissolved, hit it with the pressure washer again instead of scrubbing and rinsing and it should come right out.
5. Iron OUT Powder Rust Stain Remover
The Iron OUT Powder Rust Stain Remover is a versatile cleaner that can be used for stains around the home, so it has a mild formula. It can be used for sinks, bathrooms, and even doing the dishes or removing stains from laundry. And, of course, it can be used on your concrete driveways and patios.
To remove rust stains, start by wetting the stained area. Then sprinkle a good helping of the powder onto the stain and let it do its work. You might need to add a little more water to make sure that it is dissolving into the stain, but not too much. Let it do its work for 15-30 minutes until the stain is gone and then rinse it off. You may need a few more applications for tougher stains.
This is a good product for getting into cracks and rust pop ups because you can sprinkle the powder directly in and then add some water. It’s also a non-toxic product, so it shouldn’t damage your garden.
6. Vinegar and Baking Soda
Vinegar and baking soda is a home remedy for cleaning pretty much anything, and it works great on rust stains. Vinegar is an acid, just like lemon juice, so it will dissolve the stains. Adding the baking soda causes a fizzing reaction that lifts the stains faster and creates an abrasive mixture for scrubbing.
Start by sprinkling baking soda all over the stain. Don’t hold back, you need a good sized pile. Then, start adding vinegar a few drops at a time. If you put too much in, you will dilute the baking soda too much and the reaction won’t be as strong.
When it is a paste-like consistency and you can see it actively fizzing, let it sit for around 15 minutes. After it has had time to work its magic, give it a good scrub with a brush and then rinse it off.
If you want a natural, cheap alternative to rust cleaners, you probably already have vinegar and baking soda in the house. It might not work on the most stubborn stains but if you’re willing to use a bit of elbow grease, it will get out surface rust stains.
7. American Hydro Systems 2662 Rid O Liquid Rust Stain Remover
If you have a large concrete area with a lot of rust stains, the American Hydro Systems Rust Stain Remover is a good choice. It covers roughly 400 square feet per gallon and it’s designed for use in a sprayer. Just spray it onto the affected area and wait for the stain to dissolve before rinsing it off, no scrubbing required.
It removes stains quickly but it has an environmentally friendly, biodegradable formula so no need to worry about damage to the surrounding plants. The only issue is that it works quite slowly when used on concrete. You will need to leave it at least half an hour and sometimes more than one application is needed.
8. CLR PRO
CLR PRO is an industrial strength cleaner designed to remove limescale, calcium, and rust. It’s great for stripping rust stains off your concrete and dealing with any mineral deposits that build up. It’s a ready-to-use product that can be poured directly onto the stains.
Once it soaks in and sits for a few minutes, the stain will disappear right away. A quick scrub and a rinse and it will be as good as new. This is probably one of the fastest acting products out there.
It’s also non-toxic and recognized by the EPA as a better alternative to harsh chemical cleaners. Although there are other products that work just as fast, they tend to contain strong chemicals that damage the surrounding environment.
9. Wash Safe Industries Clear Rust Off Rust and Hard Water Stain Remover
This Wash Safe Industries Clear Rust Off and Hard Water Stain Remover is another great industrial strength cleaner that will easily melt away rust stains on a variety of surfaces. This one comes complete with a spray attachment so you simply need to attach it and get spraying. Surface rust stains should dissolve in a few minutes and rinse off easily.
However, more stubborn rust might need a few applications. It will also take off calcium and lime build up caused by hard water. This is a popular choice for rust stains around pool areas.
You may find that the stain disappears when the concrete is dry but you can still see the outline when it gets wet again. If this is the case, you’ve still got some rust deeper in the pores of the concrete. Try a few more applications and it should get rid of it for good.
Rust Removal from Concrete FAQs
Can Rust Removal Products Damage Your Grass?
Yes, some rust removal products can damage your grass. A lot of them contain harsh chemicals so you will need to cover your lawn if you use them. However, there are so many great non-toxic options out there, many of them listed above. They’re just as effective and better for the environment, so it’s best to use one of those and avoid anything with strong chemical cleaners.
Can WD-40 Remove Rust from Concrete?
Yes, WD-40 can be used to remove rust from concrete, but it’s not your best option. It will lift a surface stain fairly well but big stains require a lot of scrubbing. If you want to use WD-40, use the wide spray nozzle and give the stain a good coating, and then scrub the stain out with a brush before rinsing it.
There are better products out there for removing rust so if you’ve got a small stain and you don’t want to spend money, it’s fine. But if you have a large area to clean, I’d recommend saving yourself some time and buying one of the products listed above.
Will Bleach Remove Rust from Concrete?
No, if you put bleach on a rust stain it might look like it’s removing it but it isn’t. It simply strips the color out so it looks faded, but it isn’t actually dissolving the stain. You also reveal the layers of rust below, so it won’t make much difference.
What’s the Best Way to Clean Rust from Concrete Pavers?
Any of the products listed above will work just fine on concrete pavers. Using a ready-mixed spray-on product like the Goof Off rust remover is the easiest option because it goes on quickly and you don’t need to do any scrubbing.
Will Dish Soap Remove Rust Stains from Concrete?
Dish soap on its own is not likely to clean rust off the concrete. However, if you are using vinegar and baking soda, adding a little dish soap will help it along and clean off the dissolved rust a bit easier.
Can You Hire Someone to Clean Your Concrete Professionally?
Yes, there are professional concrete cleaning services you can hire if you don’t want to invest the time yourself. The thing is, they’ll probably use the same kinds of products that you can buy yourself, so if you want to save money, it’s a fairly easy job to do yourself.
Final Thoughts
Rust stains are an inevitability if you have a concrete driveway or patio and they can make the space look very run down. The good news is, they’re easy to get off, in most cases. Vinegar and baking soda or lemon juice are great cheap options for small spots of rust.
If you have bigger stains, there are some excellent spray on products that will dissolve all of the rust without the need for scrubbing, so it takes no time at all to get your driveway or patio looking great again.
Jamie is the founder of The Backyard Pros. When he was 15 years old he started working at a garden centre helping people buy plants, gardening products, and lawn care products. He has real estate experience and he is a home owner. Jamie loves backyard projects, refinishing furniture, and enjoys sharing his knowledge online.