How To Permanently Remove Moss From Concrete

Having a clean concrete patio or spotless driveway doesn’t just improve curb appeal; it makes the space safer and more enjoyable. Moss isn’t just potentially a slipping hazard; it’s also unattractive. That’s why most people focus on figuring out how to permanently remove moss from concrete the moment they spot it.

There are several options for removing moss from concrete. For driveways or empty patios, a pressure washer may handle the issue. You can also try regular household items like baking soda or vinegar and boiling water. However, those aren’t your only options.

Choosing the right approach may depend on the extent of the moss, the surrounding area, and your comfort with chemicals. If you need to find out how to permanently remove moss from concrete, here’s what you need to know.

Does Moss Damage Concrete?

Moss can potentially damage concrete, mainly because it holds moisture. Excess moisture can degrade many materials, and concrete is no exception. As a result, it may shorten the life of your patio or driveway simply by being present.

Depending on its location, moss growth may shift concrete pavers, widen cracks, or loosen slabs. Along with degrading the concrete, this creates additional safety hazards, so it’s wise to address the problem.

Is Moss on Concrete Dangerous?

Moss on concrete is potentially dangerous. If it moves or degrades the concrete, sudden breakage could occur when walking across the surface, or pieces of concrete may slide. In either case, falls could happen, as well as additional structural damage.

There’s also an issue with slips on moss. Moss can promote the growth of slippery algae of lichen, leading to slips that could cause injury. Additionally, pieces of moss may come loose as you walk across it, which may lead to a fall.

Since moss holds moisture, mold and bacteria may grow, creating a health hazard. Additionally, the dampness may cause nearby wooden structures to rot, leading to structural issues that could result in collapse if not appropriately addressed.

How to Permanently Remove Moss from Concrete

1. Water and a Stiff Scrub Brush

Sometimes, you can remove small batches of moss with water and a stiff scrub brush. Use a hose to soak the moss a bit. Then, use a scrub brush to pull it up.

If you can get a stiff-bristled brush attached to a broom handle, that can make the process easier. You can still scrub without bending over too much, making it effective and comfortable.

2. Boiling Water

One simplest, most accessible option for removing moss from concrete is boiling water. Boiling water will kill the moss, preventing additional growth and making it easier to remove.

Typically, you’ll start by boiling some water. Using a tea kettle can simplify application, so that’s a good option if you have one available.

Once the water boils, carefully pour it across the moss. Then, you can use a stiff brush to scrub it away once it cools. Finally, sweep up the debris and rinse the concrete with a hose.

3. Baking Soda

If you’re removing moss on a dry day, consider trying baking soda. Sprinkle the baking soda over the moss, ensuring it’s reasonably coated. Then, allow the baking soda to sit for around 24 hours.

Once 24 hours pass, take a stiff-bristled broom to push the moss off your concrete. After clearing the concrete completely, rinse it with water from a hose to remove any remaining debris or dirt.

4. White Vinegar

White vinegar is naturally acidic and an effective moss killer, especially on warmer, drier, sunnier days. Take two cups of distilled white vinegar and pour it into a spray bottle. Then, add two cups of warm water.

Shake the spray bottle gently to combine. After that, thoroughly spray down the moss with the solution, ensuring it’s well coated.

Wait for at least 24 hours before checking the moss. It should begin to dry out and die, usually taking on a brown color. If needed, spray the moss with the vinegar solution again and give it more time. Once it’s dried out, use a stiff-bristled broom to sweep it away, and use a hose to rinse the concrete when you’re done.

It’s crucial to avoid spritzing other plants with the vinegar solution along the way. Vinegar can kill most plants, so focus on the moss only.

5. Pressure Washer

A pressure washer removes moss from the concrete through force.

Follow the manufacturer’s steps to attach the water line and electric connection, ensuring the power is off until you’re ready to spray. Choose the lowest pressure setting, then work on an inconspicuous test spot.

Increase the pressure slowly until the test spot is clean. Then, continue using the spray to peel off the rest of the moss. Finally, give the concrete a once-over to get rid of additional debris.

6. Agricultural Lime

Agricultural lime works similarly to baking soda, commonly used to raise the pH levels in acidic soil. As a result, it’s safer than many alternatives, as it won’t necessarily harm nearby plants.

Apply the agricultural lime to the moss, sprinkling it over the surface until the moss is well covered. Let it sit for 24 hours before using a stiff-bristled broom to remove the moss and sweep it away. Then, rinse the concrete with a hose.

7. Bleach

Bleach can kill moss, but it’s harder to work with than natural alternatives. Bleach can harm other plants, discolor clothing, and irritate the skin, eyes, and nose.

Put on personal protective equipment (PPE) like gloves, eye protection, and a respirator. Also, choose to clothe that you aren’t concerned about damaging or put on disposable coveralls.

Combine two cups of bleach and two cups of water in a spray bottle. Put on the sprayer with the nozzle off and shake gently to combine. Then, spray the solution over the moss, ensuring it doesn’t get onto nearby plants.

Let the bleach solution sit for about 20 minutes. Then, use a stiff-bristled brush to remove the moss before rinsing the concrete with a hose. You can also wait longer if you prefer, but be aware that the bleach solution could be harmful as it sits, so that isn’t always ideal.

8. Ammonium Sulfamate

Ammonium sulfate is effective, but it’s also hazardous to work with, as it’s potentially toxic. As a result, you want to wear full PPE, including gloves, eye protection, a respirator, and even disposable coveralls.

Since it’s acidic, ammonium sulfate essentially burns the moss. You’ll want to follow the manufacturer’s directions regarding creating the solution and proper application. However, it typically involves adding up to three tablespoons to a gallon of water and then spraying the moss.

After the ammonium sulfate solution sits for the time recommended by the manufacturer, you can usually clean it off with a pressure washer or stiff-bristled broom. Use whatever process is listed in the instructions, following all safety precautions.

9. Commercial Moss Killer

Commercial moss killers contain ingredients that dry out moss, killing it and making it easier to remove.

Since the process for applying these products varies, refer to the manufacturer’s directions.

The instructions will contain details about dilution, wait times, and removal steps, so check them before beginning the process.

Will Straight Bleach Hurt Concrete?

Generally, straight bleach won’t hurt concrete. However, it’s still better to dilute the bleach before use.

Straight bleach isn’t necessarily more effective than diluted bleach if you’re trying to figure out how to permanently remove moss from concrete. As a result, not diluting essentially wastes bleach, increasing the cost of your project unnecessarily.

Straight bleach is usually more irritating to the eyes, nose, and throat than diluted solutions. Additionally, diluting reduces the bleach spread during rinsing, making it less likely to harm nearby plants or your lawn.

Is Vinegar or Bleach Better to Kill Moss?

Both vinegar and bleach can kill moss. However, vinegar is typically the better choice since it’s safer.

While vinegar scent isn’t pleasant to everyone, it’s less harmful than bleach fumes. Plus, vinegar is natural. While it can kill other plants (as bleach can), it isn’t dangerous to people, pets, or wildlife.

Vinegar is also a deterrent for many pests, it may help keep some undesirable critters away without harming them, which is a bonus.

How Long Does It Take for Vinegar to Kill Moss?

How long it takes for vinegar to kill moss can vary. While it starts working on contact, it takes time for the vinegar to penetrate.

By choosing a warmer, sunny day without rain in the forecast, the vinegar usually works faster. It’s generally recommended to give it at least 24 hours, but you’ll start noticing a difference far sooner in many cases. As a result, you may be able to rinse the moss away in just a few hours, depending on the extent of the moss.

How to Remove Moss from Between Concrete Slabs and Paving Stones

While tackling moss on your concrete is critical, removing it from between concrete slabs and paving stones is also necessary. Since it’s against the concrete, the moss can push it out of position. Plus, it will eventually grow over the concrete, giving it a chance to damage the material and cause a safety hazard.

Usually, the best way to remove moss from between concrete slabs and paving stones is to apply the same vinegar solution as outlined above. Let the vinegar solution sit for 24 hours, allowing it to kill the moss.

Next, take a plastic putty knife and use it to physically remove the dried-out moss. Then, you can either leave the resulting spaces or fill them with your preferred material.

How to Prevent Moss from Growing on Concrete

Whether you just finished removing moss from your concrete or simply want to avoid the issue in the future, taking steps to prevent moss growth is wise. Here are some simple places to begin.

Clean Regularly

In many cases, regular cleanings are the easiest way to prevent moss from growing on concrete. By sweeping the dirt away consistently, there isn’t a suitable base for moss. Plus, small pockets of moss are usually easy to dislodge with a stiff-bristled broom or pressure washer.

How often you need to clean depends on how quickly your concrete gets dirty or moss-covered. A weekly, biweekly, or monthly schedule may all work.

When you clean, you can also use a vinegar solution. Sweep away excess debris, spray on the vinegar, and use the stiff-bristled broom to scrub it lightly. Then, rinse with a hose.

Prevent Soil Erosion

While moss can grow on various surfaces, it’s more likely to develop on concrete if soil ends across your patio or driveway. By preventing soil erosion, you can limit the spread of dirt onto your concrete, reducing the odds that moss will grow.

The best options for preventing soil erosion depend on your yard. You may want to add new retaining walls or plant grass or plants that steady the soil if you have empty spots.

Edging the concrete slab could also help. Adding a layer of plastic sheeting, covering it with stone or gravel, and installing a decorative border may limit the amount of soil that gets drug onto your concrete. Similarly, it could allow water moving across your lawn after it rains to drain around the slabs, effectively steering dirt away from the surface.

Allow Sunlight to Hit the Concrete

Moss generally needs shady, damp spots to grow effectively. Since nearby trees or bushes can create shadows, those areas may see more moss growth. Similarly, awnings or patio covers can create shade.

By removing overhanging tree branches, trimming back shrubs, and shifting awnings that cause shadows, the sun can hit the concrete. Sun on the concrete warms the surface and speeds up water evaporation. As a result, the concrete isn’t the best environment for moss, leading to less growth.

A lot of direct sunlight and warm temperatures may even kill moss on concrete. Moss needs moisture, so a significant amount of direct sunlight may dry it out too much, causing it to die. However, this usually only happens if the temperature is also high, so keep that in mind.

Apply Copper Sulfate

Copper sulfate is generally safe for people and pets and is also an excellent moss deterrent. By applying a solution to your concrete, you’re essentially coating the surface with a natural biocide.

Usually, copper sulfate comes in crystal form, and you dilute it in water to create the solution. The right ratio can vary depending on the manufacturer, so read the directions to ensure you get the proportions right.

Wait for a dry day to apply the copper sulfate solution, preferably during rain-free weather, to ensure your concrete is completely dry. After that, spray the concrete with the solution to coat it. Make sure you don’t create a lot of runoff, as copper sulfate can kill grass, other plants, and even trees.

Let the solution sit and dry. Additionally, don’t rinse, as that can wear away the coating, making it less effective.

In many cases, you’ll need to reapply the copper sulfate every so often, particularly if it rains. Make sure the concrete dries out before reapplying, and use the process above to create the new coating.

Fix Leaks and Address Puddles

When you have a leaky downspout or outside faucet, it makes the surrounding area damper. Similarly, spots that frequently end up with standing puddles after rain create a moisture-rich environment in your yard.

By fixing leaks and addressing puddles, you limit the available moisture. Check your faucets and repair them if they’re dripping. Check downspouts to ensure they’re not holding water or directing runoff toward your patio or driveway.

You may need to fill low spots in your yard and plant grass for puddles. Removing any items that collect water near ground level close to your concrete is also wise. Otherwise, you may need to tip those items to help them drain if they fill up or add holes for better drainage if appropriate.

It’s also smart to look at the position of any sprinklers. If they’re spraying your concrete whenever their own, reposition them to ensure they aren’t hitting patios, driveways, or sidewalks. That way, your concrete stays drier, reducing the odds of moss.

The Best Way to Permanently Remove Moss on Concrete

While any of the options above can permanently remove moss on concrete, the white vinegar solution is often the best place to start. It’s a natural option instead of a chemical-based one, and it’s fast. However, a pressure washer is also a good choice if your concrete is in good shape, as it only relies on pressure.

Did you learn everything you wanted to find out about how to permanently remove moss from concrete? If someone in your life is battling moss on their concrete patio or driveway, share the article.