Prep first
Before you start
- Check whether the mark is hard and orange-brown, which points to rust, or slimy and pink-red, which points to a bacterium.
- Pretest the paste on a hidden spot before you cover the stain.
- Don't use chlorine bleach on a rust mark. It sets the rust.
Orange stains on a concrete driveway usually come from water running over metal or from a rusting object left sitting on it. Iron oxidizes as it sits in the air, so a fresh mark comes up much more readily than an old one that has sat for weeks. Expect a fresh mark to lighten after one round of paste, while an old one can need the paste left on for several days.
For a red mulch stain on concrete, brush off loose mulch before any paste goes on, so the color doesn't get pushed deeper. If the paste stalls on an old orange stain, a rust remover made for hard surfaces is the next product to test. Look for a little lift with each round, since that tells you the approach is working and you don't need anything stronger yet.
Before you start
What concrete, brick & driveways can take
Safe to use3
- Water
- Hot water
- Soaking
Use with care5
- Chlorine bleach
- Oxygen bleach
- Solvents (alcohol, spot removers)
- Acids (vinegar, lemon)
- Scrubbing and abrasives
7 items
What you'll need
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- Lint-free glycerinThe main ingredient, at 7 parts. (opens Amazon)
- Sodium citrate crystals1 part of the paste; sold at drug stores.
- WhitingThickens the mix into a paste. (opens Amazon)
- Lukewarm water6 parts, used to mix the paste.
- Wooden scraperLifts the hardened paste off.
- Clear waterFor the final rinse.
- Rubber glovesNeeded if you decide to use a rust remover. (opens Amazon)
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5 steps
Step by step
Step 1 of 5
Test a hidden spot first
Pretest the paste on a hidden area of the concrete before you use it on the stain. Also check the mark: hard orange-brown points to rust, while slimy pink-red points to a bacterium that needs a different treatment.
Step 3 of 5
Spread the paste and let it harden
Apply the paste over the stain and let it harden in place. It can stay on the stain for several days if the mark is stubborn.
Careful. Keep acid out of the paste, since whiting foams and destroys an acid's power.
Step 4 of 5
Scrape off the hardened paste
Remove the hardened paste with a wooden scraper. If the stain is still visible, mix a fresh batch and repeat the spread and scrape.
Step 5 of 5
Rinse and let it dry
Wash the area thoroughly with clear water. Let it dry completely, then check the color before deciding on another round.
If you'd rather buy than mix
Best products for orange on concrete, brick & driveways
If the paste doesn't lift a deep mark, a proprietary stain-specific cleaner is the next product to try, tested on a hidden spot first.
RUST AID Bathroom Rust Remover
CLR Calcium, Lime & Rust Remover
How we picked these: each product is made for this type of stain, its maker doesn't warn against using it on concrete, brick & driveways, and its directions fit the steps above.
Finished the steps? How does it look?
Nice work. Let it dry completely and check it again in good light. Here is what done looks like:
How to tell it's really gone →A faint mark usually needs one more round, not a stronger product.
Heavy buildup usually takes more than one round.
Heavy or long-standing buildup →When to call a professional →How to tell it's working
The color should fade after each round of paste, and the rinse should carry away a little more with each pass. Wait for the slab to dry before you judge a spot, since damp concrete reads darker than it really is. If the color is still bright after two full pastes, the iron has set in, so switch to the old and set-in stains section.
What changes for yours
Adjust for your concrete, brick & driveways
Concrete driveway
On a driveway, the orange usually comes from a rusting metal item left on the slab, such as a bucket, tool or planter, or from iron in sprinkler water. Find and remove the metal object first, or the stain can keep coming back.
Use the same paste on the driveway, and repeat the spread, scrape and rinse until the color is gone.
Red mulch
Red mulch can leave a mark that looks just like rust, so start with the same hidden-spot test and the first steps. Move the mulch off the slab while you work so the color doesn't keep transferring.
If the mark doesn't change after a full round, stop and check the color again before you add any other product.
Rusty metal item
A bucket, tool or planter sitting on concrete is one of the most common sources of an orange mark. Move the object off the slab and dry the area before you start.
If the mark reappears after cleaning, the metal is still the source, so remove it for good.
Blue-green copper
Blue-green marks come from copper dissolved by corrosive water, so they aren't rust and the orange steps won't clear them. Check the water source and fix that problem first.
Keep the paste for the orange and red marks only, and treat the blue-green one as a separate job.
Heavy or long-standing buildup
Old stains that have built up over years need a deeper poultice. Spread it at least 1/8 inch thick, cover it with plastic and leave it for 24 hours.
Let it dry fully before you scrape or brush it off, and repeat as needed until the color stops lifting. Proprietary stain-specific cleaners are a better choice than homemade mixes if the stain is still there after several rounds.
Older stains need stronger methods, and each one carries more risk of damage to the concrete. Keep your expectations realistic and test any stronger product on a hidden spot first.
Vinegar, baking soda, peroxide and more
Do home remedies work on orange on concrete, brick & driveways?
Most household remedies don't belong on an orange concrete stain. The method above is built around a glycerin and whiting paste, so nothing else needs to be added to it. If the red came from mulch, use the same first check before you pick a remedy.
Skip6
What makes it worse
Mistakes to avoid
Don't use chlorine bleach on this stain
Bleach is the first thing many people reach for, but it sets rust and intensifies the orange. Until you know the mark is iron, keep bleach away from it.
Don't mix bleach with vinegar or acid cleaners
Mixing chlorine bleach with vinegar, lemon juice or an acidic rust cleaner releases chlorine gas. Keep the two apart, and rinse everything out before you switch products.
Don't scrape the paste too early
The paste has to harden fully before you touch it, or you'll drag soft rust across the slab instead of lifting it. Wait until it's firm, then work it off with a wooden scraper.
Don't use a metal scraper
A metal blade can gouge the concrete and leave flecks of iron that rust into new marks. A wooden scraper does the same job without that risk.
Don't skip the hidden test spot
Rust removers are strong acids, so a patch on an out-of-sight corner shows how the concrete reacts before the whole slab is exposed. Pretest every product you add, even one you've used before.
When to call a professional
Call a professional if a water repellent on the concrete keeps the paste from working, or if the mark is old and nothing has moved it after a full round. Tell them the stain is orange, that you used a glycerin and whiting paste, and whether any bleach touched it. A testing lab can identify a mark you're not sure about.
Questions
What causes orange stains on concrete?
Orange to reddish-brown stains are most often iron, which comes from water or rusting metal. Iron oxidizes when it meets air, and chlorine bleach makes it worse. Look for a rusting object on the slab or iron in the water supply to find the source.
Can a red mark from mulch be treated the same way?
A red mark from mulch can look just like rust, so treat it as the same stain until you know otherwise. Start with the hidden-spot test and the steps above, then judge the result before you add anything else.
What if the stain is pink-red slime?
Pink-red slime is usually the bacterium Serratia marcescens, and it can return after cleaning. It's a different problem from rust, so the orange steps won't clear it.
How long can the paste stay on the stain?
It can stay on for several days if the stain needs it. Check the color each day, and once it has lifted, scrape the paste off and rinse.
Can I pressure wash the orange stain off my driveway?
Skip the pressure washer for this stain. High-pressure washing can erode the surface of concrete, and the paste is the method built to draw the iron out. Rinse gently with clear water once the paste is off, and let the slab dry before you judge the result.
Should I wet the concrete before I spread the paste?
Yes. Saturate the area with clear water first, since masonry gets this treatment before any cleaning solution goes on. Rinse with clear water afterward, and let the slab dry completely before you decide whether the mark has changed.
Can I use bleach on an orange stain on concrete?
No. Chlorine bleach makes rust worse because it sets the iron and deepens the color. If you're not sure the mark is rust, test a hidden corner first and have it identified before you reach for bleach or any other strong product.
Orange on other materials
Other stains on concrete, brick & driveways
Start from the bigger picture
How we know this
Every method, amount and warning here comes from university extension services, industry bodies and product makers. We read them, check every step for unsafe combinations and changed amounts, and write it up so you can follow it.