First few minutes
Just happened? Do this first
- Act quickly: fresh blood is much easier to lift than a stain more than 24 hours old.
- Use only cool water at first. Hot water sets blood.
- Blot with a clean, dry white cloth or paper towel, and don't rub, which spreads the stain.
- Test any remover on a hidden spot first and stop if color transfers or changes.
Blood on concrete is a protein stain, and a rough, porous surface lets it sink into the texture before you can reach it. Fresh blood usually lifts with cool water and a detergent solution, but dried blood can leave a shadow even after the steps. Keep the area wet while you work, since dry concrete pulls in the cleaner and whatever it's lifting.
Rinse the spot with cool water before you scrub, so the blood doesn't sink deeper into the pores. Use a stiff non-metal brush in small circles, since a metal one can grind blood into rough concrete. If the stain has been sitting for days, don't reach for anything stronger; repeat the detergent brush and rinse once the concrete is dry, and give it a few more rounds.
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
8 items
What you'll need
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- Clean spongeLifts the blood with cool water without spreading it. (opens Amazon)
- Stiff non-metal brushWorks the detergent into the concrete texture without scratching it. (opens Amazon)
- Laundry detergentThe cleaner for the main pass. (opens Amazon)
- Washing soda (optional)An alternative to the detergent, used in warm water. (opens Amazon)
- Rubber glovesNeeded if you use washing soda. (opens Amazon)
- Plain water and a bucket or hoseTo saturate the area and rinse it. (opens Amazon)
- Enzyme presoakFor dried or old blood.
- 3% hydrogen peroxideFor blood still visible after the soak. (opens Amazon)
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6 steps
Step by step
Step 1 of 6
Blot up the fresh blood
Dampen a clean sponge in cool water and dab at the blood, working from the outside edge toward the middle so it doesn't spread. Rinse the sponge often and turn to a clean section as it picks up color.
Step 2 of 6
Wet the concrete around it
Pour or spray cool water over the stain and a margin of concrete around it until the surface is saturated. Keep the area wet while you work, and rewet any spot that starts to dry.
Step 3 of 6
Brush in the detergent solution
Mix laundry detergent into warm water, then brush it into the stain with a stiff non-metal brush in small circles. If you use washing soda instead, dissolve it in warm water and work it in the same way.
Careful. Washing soda is highly toxic: keep it off your skin and wear rubber gloves.
Step 4 of 6
Rinse with plain water
Flush the area with plain water until the suds are gone and the runoff is clear. Work the water across the whole cleaned patch, not just the spot.
Step 5 of 6
Let the area dry fully
Leave the concrete to air-dry completely, and keep foot traffic and pets off it until it has. Drying is when the true result shows, because the cleaned patch can look different while it is still wet. Once it is dry, look at it in daylight and decide whether another pass is needed.
Step 6 of 6
Repeat once if a shadow remains
If a faint shadow is still there once the concrete is dry, brush the detergent in again and rinse. If it is still visible after one repeat, move on to the soak for dried stains.
If you'd rather buy than mix
Best products for blood on concrete, brick & driveways
Look for an enzyme-based presoak for dried or old blood, and pick a stain-specific product over a homemade mix.
Amazon Basics Microfiber Cleaning Cloths
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.
If the stain was already dried or set, the method changes.
Old, dried or set-in stains →When to call a professional →How to tell it's working
Each scrub and rinse should lighten the mark, so watch for that. Judge the final result only once the concrete is fully dry, since damp concrete always looks darker. If the mark hasn't changed after two rounds, the stain has likely set and calls for the enzyme soak.
What changes for yours
Adjust for your concrete, brick & driveways
Rough outdoor concrete
Blood can settle into the pits of rough outdoor concrete, so a faint shadow after the first pass is common. Treat it with one repeat of the brushing before you move on to the soak.
Work in smaller sections so the water and cleaner stay where you put them. Rinse each section before you start the next one.
Cement floor
Cement floors in garages, basements and workshops are often painted or coated, so look at the finish before you wet it. Once you know what it is, use the same steps and keep the water to the stain itself rather than the whole floor.
Indoors, a small amount of water goes further, and wiping up wet spots as you go keeps the floor from getting slippery.
Old, dried or set-in stains
Old blood that has soaked into concrete needs more than the cleaning steps above. Scrape or brush off any crusted matter first, then soak the area with a product containing enzymes in warm water for at least 30 minutes, or several hours if the stain is aged.
Dried and old protein stains may need several rounds, so expect to repeat the soak. After it, lay an enzyme-dampened pad on the stain for 30 minutes. If blood still shows, brush on 3% hydrogen peroxide for 1 to 3 minutes and rinse with plain water.
For a deep, localized stain that still won't lift, make a poultice of talc, whiting, fuller's earth, diatomaceous earth or clay with the right solvent, spread it at least 1/8 inch thick, and cover it with plastic for 24 hours. Let it dry, then scrape or brush it off and repeat as needed. A stain-specific commercial cleaner is a safer bet than a homemade mix, and very old stains carry more risk of damage to the concrete.
Vinegar, baking soda, peroxide and more
Do home remedies work on blood on concrete, brick & driveways?
Most household remedies you will see for blood don't belong on concrete. The ones below are the common picks, with what to do instead.
Helps1Skip3Avoid2
What makes it worse
Mistakes to avoid
Don't leave the peroxide on too long
Hydrogen peroxide is a bleach, and it is meant to work for only 1 to 3 minutes. Leaving it longer raises the risk of lightening the concrete, so rinse it off when the time is up.
Don't mix cleaners on the same spot
Rinse each product out with plain water before you move to the next one. Chlorine bleach mixed with ammonia, vinegar, other acids or rubbing alcohol can give off toxic fumes.
Don't scrub painted concrete hard
Flat or matte painted surfaces can be dulled by hard scrubbing, so keep the brush strokes light and let the cleaner do the work.
Don't scrub with a wire brush
Steel bristles dig into the pores and leave tiny rust flecks that look like fresh stains. Use a stiff nylon brush with the detergent solution instead.
Don't blast the surface with high pressure
A pressure washer turned up high erodes the cement and roughens the top layer, so the next spill soaks in faster. Keep the pressure low, with a wide fan tip held well back from the surface.
Don't use muriatic acid on the stain
Unbuffered muriatic acid can leave an acid burn and new discoloration, and it can eat at any mortar joints nearby. Blood doesn't need it, so stick with detergent and a thorough rinse.
When to call a professional
Call a masonry restoration specialist if the concrete is historic or a water repellent is blocking the cleaner from working. Don't move to stronger chemicals to chase a shadow, because harsh products can leave a stain of their own. If you can't tell what the mark is, a testing lab can identify it.
Questions
Does blood stain concrete?
Yes, blood can leave a visible stain, especially once it dries into the pits of the surface. Fresh blood usually lifts with cool water and the detergent steps above.
How long can blood sit on concrete before it's too late?
Fresh blood is much easier to remove than a stain more than 24 hours old, so act right away. Older stains aren't hopeless, but they need the enzyme soak and several rounds.
Will the stain come out of painted concrete?
Often, if you act quickly. Painted concrete needs a lighter touch, so use cool water and the detergent step and avoid oxygen bleach and hard scrubbing.
Can I come back to a stain after it dries?
Yes. Dried stains often need several passes, and each pass should be followed by a full dry before you check the result. Older accumulated stains need stronger methods with more risk of damage, so weigh that risk before going further.
Why does the spot look darker after cleaning?
Wet concrete looks darker than it will once it has dried, so the spot can look worse until it is fully dry. Judge the result only after drying, and repeat the brushing once if a shadow remains.
Can I pressure wash a blood stain off concrete?
Yes, but only on low pressure. Keep the nozzle on a low setting with a wide fan tip held at least 12 inches from the surface, and add warm water with detergent rather than more force. Older stone or historic pavers shouldn't be power washed at all.
Why should I wet concrete before I clean it?
Dry concrete pulls in whatever you put on it, the cleaner included, so everything soaks deeper than you want. A wet surface keeps the cleaner and the loosened blood near the top, where a thorough rinse can carry it away. Keep it wet until the final rinse.
Is bleach worth trying on concrete?
Bleach is for moss, algae and similar growth, not for blood, and it isn't a good fit for natural stone. Never mix it with ammonia, since the two together release a toxic gas. Rinse with plain water before anything else touches the spot.
Blood 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.