Retaining walls are one of the most important elements in hardscape. There are tons of creatives ways to use and incorporate in any number of designs. As time goes by, it gets dirty, and it often presents forms of mold and moss. So, how to clean mold off retaining walls?
Mold, moss, and mildew, although are different things, all belong to the same category of problem. Therefore, they are all treated the same way. These elements are formed over time due to the accumulation of biological dirt and moisture, specially in places where the sunlight doesn’t hit.
Getting rid of mold can be challenging sometimes. It all comes down to what material exactly are your retaining walls made of. Each material has its specific conditions and needs to be handles differently.
The most common materials used for retaining wall blocks are natural stone and concrete blocks, but is not exactly to see brick pavers also be used to create small retaining wall, specially in gardening settings.
So let’s get right into the details of each material and teach you how to clean mold of retaining walls.
How to Clean Mold off Retaining Walls – A Very Important Warning
Before moving on to the actual guide, first we want to clear something up.
A very common and, unfortunately, widespread practice is using vinegar or even bleach to get rid of mold. We can’t stress enough how dangerous that is and we absolutely do not recommend that practice.
Vinegar and bleach are very acidic products that can severely damage your retaining walls, specially if it is natural stone. To clean retaining walls and pavers, you should always use products with a low pH value, like neutral soaps and specialized stone cleaning products.
Also, we can’t forget about sealing. Pavers and retaining walls alike need to sealed in order to be protected from stains, weather and effects and, even more important for the purposes of this article, mold, moss, and mildew.
So sealing by itself is already the best thing you can to prevent the formation of mold in your retaining walls.
Vinegar and bleach, being highly acidic, remove the sealing where they are applied. Yes, they kill the mold, but also leave your retaining walls exposed and unprotected, so it is definitely not a good idea to use them.
There are many specialized products in the market designed to clean mold (one of which we will talk about later on), so there’s no reason to rick damaging your installation just to save a few bucks. You might have to spend even more in the future to fix it in case things go south.
Proper Way to Clean Mold
You start simple, with one of the best tools to clean retaining walls and pavers: a pressure washer. If it has a hot water option, even better.
Be careful though. Don’t use too much pressure and stay at a safe distance from the surface. Start with the lowest pressure and slowly increase it until you see the dirt and mold being cleaned away. Don’t forget that sealing is always recommended after a pressure washing session.
If the pressure washer doesn’t do the job, there are many natural stone cleaners that you can use to help you. They also work on concrete and bricks. They have low pH and are designed to maintain the pristine appearance of natural stone after usage.
In our experience, one of the best products you can use is the Wet & Forget Concentrate.
Using it couldn’t be easier. Simply mix it with water in a tank sprayer and spray the affected area. No need to scrub or even rinse it afterwards. Just leave it there acting for as long as it takes, that’s where the name comes from, right?
It does work and, even better, it doesn’t affect the sealing. There’s already a much less chance that mold appears through sealing, but in the off chance that it does, you can simply spray the area with the product and literally, forget about it as it slowly cleans it.
Not only that, it also keeps mold from appearing again for as much as a year. So sealing in combination with Wet & Forget is a powerful combination that has the potential to eliminate your mold problems right away.
When in Doubt, Call a Professional
So, pressure washing and specialized stone cleaning products are the way to go when it comes to getting rid of mold. Those things are all relatively safe to use, as long as you follow the instructions on the cleaning product and manage correctly the pressure on your pressure washer.
The appearance of mold, and it’s relatives moss and mildew, is directly related to how your retaining walls are installed. Drainage is always extremely important to prevent the excess moisture in the area, and correct choice and applications of materials greatly influence it as well.
It might be tempting to tackle hardscape projects from a DIY perspective. And that is fine, as long as you do a proper research first. But no amount of research will replace the experience of a qualified professional.
Cleaning you can safely tackle by yourself, but when it comes to installing and sealing, the help of professionals if pivotal for a successful hardscape project.
Here at JS Brick, over our 22 years of activity, we have been called to fix many problems that wouldn’t even exist in the first if not for mistakes in installation and sealing. So, we highly recommend you hire a qualified hardscape contractor in your area to help you.
And if you happen to be around our area of activity, why not give us a call to help you? You can contact us any time at +1 941 586 9140 to schedule a free consultation on your project. We would be happy to hear from you and help you with any hardscape need you might have.
