Green algae on concrete pavers isn’t just ugly, it’s also slippery and unsafe. If your patio, concrete driveway, walkway, or any concrete surface is covered in green deposits, you’re not alone. Algae thrive in damp, shady areas, and concrete or stone are the perfect materials for it to grow. The good news? Cleaning it off isn’t difficult.
With the right approach, you can remove algae from your outdoor spaces and prevent it from coming back. Here’s how to do it.
The Best Way to Clean Algae Off Concrete Pavers
A few simple tools and a little elbow grease can make your pavers look new again.
To clean algae off concrete pavers, you don’t need harsh chemicals. A few household items and a good scrubbing will do the trick.
- Sweep the area – Remove loose debris like leaves and dirt so they don’t get in the way.
- Mix your cleaning solution – A mixture of water and white vinegar (1:1 ratio) works well. For tough spots, add a few drops of dish soap to your cleaner.
- Scrub the paver surfaces – Use a scrub brush or other stiff brush to scrub the area. If it's stubborn, let the solution sit for 10–15 minutes before scrubbing again.
- Rinse thoroughly – Use a garden hose or a bucket of clean water to rinse away the algae and cleaning solution.
- Let it dry – Sunlight helps kill any leftover algae spores and prevents new growth from forming.
If you prefer a faster cleaning method, a pressure washer on a low setting can blast it away without chemicals. Just be careful—too much pressure can damage the patio surface. Learn from a mistake I made the first time I pressure washed a patio... it can also blast out polymeric sand or whatever joint sand you're using between your pavers.
How to Prevent Algae Buildup on Concrete Pavers
A few small changes can stop it from coming back.
Algae thrive in shady, damp conditions, so the best way to prevent it is to change the environment.
Try these simple steps:
- Increase sunlight exposure – Trim back trees or bushes that keep areas shady.
- Proper drainage – Make sure water isn’t pooling on the paver surfaces after rain.
- Keep pavers dry – If possible, sweep off standing water after a storm (a leaf blower makes quick work of this).
- Regular cleaning – A quick sweep and rinse every few weeks prevent buildup.
- Use a mild treatment – Spraying pavers with a vinegar solution once a month can stop algae before it starts.
Sealing your pavers can also help. A good sealant creates a barrier that makes it harder for algae to take hold.
Can You Use Bleach to Clean Algae Off Concrete?
Bleach works, but it’s not the best option. A bleach solution can kill it fast, but it can also harm plants, pets, and nearby grass. If you use it, dilute it as one part bleach with five parts water. Apply it with a spray bottle, let it sit for 10 minutes, then scrub and rinse well. If you have plants near the area, cover them with plastic before spraying.
Why Does Algae Keep Growing on My Concrete Pavers?
Simply put, it's environmental. Lack of sunlight and moist spots create the perfect conditions for algae growth.
If it keeps coming back, check for areas that stay damp or don’t get much sunlight. Water from sprinklers, poor drainage, or heavy shade can create a constant problem. Making small adjustments to reduce moisture levels on your outdoor surfaces, like redirecting water flow or trimming back trees, can make a big difference. Keeping your concrete patio clean doesn’t have to be a big job. A little regular maintenance can keep algae away for good.
