How to remove Rust from Concrete
First 60 seconds
Do not reach for a rag and start scrubbing yet. Blot — do not wipe the rust from the concrete, working from the outside edge of the stain inward so it cannot spread any further. Bleach actually reacts with iron oxide and can make rust stains darker and permanent, and highly porous and alkaline, so it can pull stains deep if not treated quickly.
What you'll need
- Lemon juice
- Table salt
- White vinegar
Step by step
- Gather your materials before you start — set out everything so you are not searching mid-treatment.
- Lemon juice: apply directly and let it sit in sunlight for a natural bleaching action.
- Table salt: pile on salt to draw the liquid out while it is still wet.
- White vinegar: mix one part vinegar with two parts water.
- Rinse and blot dry with a clean cloth, then press with dry towels and change them until no more transfers onto the towel.
Do not do this
- Chlorine bleach. It can react with the stain or the material and cause discoloration.
- Ammonia-based cleaners. Mixed with certain stains it can release harsh fumes or set protein.
Common questions
Can I use hot water to remove rust from concrete?
Hot water is not usually necessary, but on concrete it is safer to stay with cool water regardless, since highly porous and alkaline, so it can pull stains deep if not treated quickly.
Is it safe to scrub the stain out?
Scrubbing usually makes things worse. Blot or lift instead of rubbing, working from the outer edge inward so the stain does not spread.
What if the rust stain has already dried?
A dried stain takes longer and may need repeated treatments, but the same agents still work — just re-wet the area gently first to reactivate the stain before treating it.