How to Get Rid of Moss on Concrete

Moss on your concrete driveway, patio or pathway can soon make it look unsightly. Leaving it untreated for too long will see your surface take on a look far removed from the one you hoped it would maintain forever. Furthermore, once moss takes hold, it can lead to substantial damage to the concrete and even pose a safety risk to those who may travel across the surface.

A while back, we spoke about getting rid of moss on a tarmac driveway, and much like tarmac, concrete often requires a similar approach.

Why does moss grow on concrete?

Moss loves a cool, damp surface shielded by the sun. Add in a constant source of moisture, and it can soon call anywhere home. When it comes to concrete, it’s almost as if moss has found its very own five-star hotel. With the nature of concrete allowing it to be porous, water is easily absorbed, providing a constant energy source to the moss that may have staked a claim to the area. When you combine this with shade, its chances of making the area a permanent residency increase immensely. As it settles into its new home, it finds cracks within the concrete and uses them to firmly affix itself to the surface and continue its growth.

This soon leads to concrete driveways, patios, walls and roofs being overrun. Luckily, some quick wins can solve the problem.

Why do I need to remove moss on concrete?

Leaving moss on concrete is a bad idea. Of course, you may not fancy tackling the problem; we all want an easy life, right? But leaving moss on concrete could soon cause you bigger issues than expected.

Untreated moss on concrete could see any, or all, of the following happen:

• Slips, trips and falls: Moss stores lots of moisture and makes a concrete path, driveway or patio extremely slippery. Should it be left untreated, family, friends or colleagues could have a fall that results in serious injury.
• Loss of house value: Moss doesn’t look particularly welcoming and can soon dent your kerb appeal. This could see potential buyers put off or at least come in with a lower offer. Research shows that 90% of buyers would reduce their offer based on kerb appeal!
• Structural damage: Moss digs in deep when it settles. It exploits cracks in the concrete and leads to them getting much worse. With all the moisture it retains too, you could soon see weaknesses developing as the surface gradually degrades.
• Rapid regrowth: When you attempt to kill moss on a concrete surface but don’t do it effectively, it can grow back fast. This sees you revisiting the surface frequently fighting a battle you cannot win.

How to remove moss from concrete?

If your concrete surface has become infested with moss, you’ll want to tackle it as soon as possible. Once moss finds a suitable place to settle, its growth can be rapid. We’ve picked some of the best ways to kill moss on concrete that should see you have your surface looking back to its best.

Vinegar

An easy way to kill moss on a concrete surface is with a product you’ll likely find already at home. With just a spray bottle, some vinegar, some water and a stiff brush, you could say goodbye to the moss within the hour.

• Fill a spray bottle with white vinegar.
• Soak the moss with the vinegar.
• Allow the vinegar to soak in for 15-30mins (the thicker the moss, the longer you should leave it)
• Use your brush to break down and loosen the moss.
• Fill a bucket with water or use a hose and pour/spray over the moss and vinegar.

This should remove the moss, but remember, moss can be stubborn. It can settle deep within the concrete, so you may need to try a few times before it is completely removed.

Bleach

Bleach is another product you likely already have access to. However, it should only be used with safety in mind. Bleach can kill the moss on your concrete surface, but it can also damage the surface at the same time. As a result, you must dilute the bleach before applying it.

• Dilute the bleach with water. Ideally, 1 part bleach to 10 parts water.
• Pour this mixture into a spray bottle.
• Soak the affected area thoroughly.
• Allow the bleach/water mix to soak in for at least 15 minutes.
• Use a scrubbing brush to remove the moss.
• Rinse away any debris and bleach with water.

Due to the chemical nature of bleach and the risk it poses to health, always wear gloves and goggles alongside appropriate clothing before attempting to remove moss in this way.

Boiling water

The next option that’s readily available is boiling water. Water at high temperatures kills moss on concrete and won’t cause harm to your surface either, unless you decide to pour it on when the concrete is frozen or extremely cold!

Making sure you choose the right time of year (basically not when it’s cold!), You can easily kill moss with water.

• Boil a kettle.
• Slowly soak the affected area.
• Wait for 5-10mins or until the moss has turned brown.
• Use a scrubbing brush to remove the moss.
• Rinse off the area, removing any debris.

Baking soda

The last of the “at-home” solutions for killing moss on concrete is baking soda. It tends to work a little slower than the other options we’ve looked at, but it is one of the safest.

• Pour baking soda over all the moss.
• Leave it for 24 hours.
• Scrub the whole area to remove the moss and baking soda.
• Rinse away any debris.

Can I use a pressure washer to kill moss on a concrete surface?

You can use a pressure washer if you want to remove moss from concrete, but you’ll need to be careful. Pressure washers are powerful and can easily cause damage to your surface. It’s a quick solution, but if you don’t have a pressure washer to hand, it can be expensive should you decide to hire or buy one. That being said, its capabilities mean you will give your entire surface a clean and finally get rid of oil on the driveway or those black spots that have been driving you mad!

You’ll also have the noise factor to think about. In a built-up neighbourhood, a pressure washer might not be the most welcome choice.

Should you decide to use a pressure washer to tackle moss on concrete, here’s what you need to do:

• Rent or buy a pressure washer. Check it’s suitable for use on concrete first.
• Set the washer to a low setting and follow all instructions for use. Even down to what safety gear you might need to wear.
• Spray the water in a sweeping motion over the moss with the hose being about 30cm away from the concrete.
• Keep applying the water until the moss is gone and the concrete is clean. If there is no change, consider turning the washer up to the next setting.

How do you kill moss on concrete with moss killer?

Moss killer is a chemical that breaks down the moss and stops it from regrowing. Purchased from garden centres and other similar stores, it’s a quick and easy solution to your moss on concrete problem. It requires you to be a little careful; the chemicals can be strong and dangerous. Wear suitable clothing and always follow the instructions before use.

• Apply the product to the affected area.
• Leave the moss killer to soak for 2-4 hours.
• Rinse with water to remove debris and traces of the weed killer.

This should be enough to remove the weed killer, but if it isn’t. Repeat the process.

How can I stop moss from growing on concrete?

If you have successfully removed moss from your concrete surface, you won’t want it to reappear. There are a few things you can do to stop the moss from growing back.

• Keep the surface as dry as possible.
• Regularly clean the surface.
• Increase access to sunlight.
• Frequently sprinkle salt, baking soda or lime over the concrete. If you have none, consider vinegar, lemon juice or bleach.

Killing moss on concrete can be easy, but it is best attempted as soon as you spot moss growing. Leaving it too long leads to long-term damage and repeated attempts to kill it. Should you have reached the point of no return, speak to our team. We are the concrete surfacing specialists for Sussex, Surrey, Kent and Hampshire. With years of experience laying concrete driveways, patios, paths and more, you can rely on us to deliver a premium surface at an affordable price.