Has it been constant gloomy weather and rain where you live? Not good for the mood, but your outdoor plants will surely be loving it.
Speaking of plants and all things that love moisture, can we talk about a common outdoor mold/fungus problem?
Nowadays, most of us have an outdoor patio with colored precast concrete paving stones. It doesn’t take long each year for black mold and mildew or moss and algae to start growing on it.
It is a mind-numbing job that will take hours and hours of work to restore the patio to a brand-new condition and everyone who has tried it hates doing that job.
What we need to ask is if there’s a way to prevent the moss, mildew, and mold from growing in the first place and why is it growing on the precast concrete pavers.
Moss, mold, and mildew need food to survive, just like us, the only difference being, the source of food. Specks of dust, ultra-fine sugar aerosols from trees and bushes, tree sap, minerals, organic debris, etc., are all food sources for the unsightly things growing on your patio.
The missing ingredient needed to fuel the moss, mold, and mildew growth is, of course water. If you were somehow able to keep your patio completely dry always, you’d not have any growth. But even morning dew can sustain the green and black organisms as they’re tenacious and know how to make a little water go a long way.
The good news is that there are ways you can prevent the growth of patio moss, mildew, and mold. But they’re not always advised. Let’s take a look at the possible ways to address the issue at hand.
Power washing it at least once a year will solve the problem but it’s only a temporary solution. Besides power washing will damage your patio in the long-run, hence, this quick solution is not advised to be used each time there’s mold growth. In addition, power washing, regardless of the fact that it is destructive to the concrete pavers, provides more moisture to the mold and therefore aids in its growth
Let’s discuss power washing in detail. There’s a raging debate going on in the home improvement community about whether or not power washing can be destructive to concrete, brick, precast pavers and wood. The unequivocal answer is yes, it’s destructive and the rate of destructive force is directly proportional to the pounds-per-square-inch (psi) power the machine delivers, the angle of the spray-wand tip and the distance of the tip from the surface being cleaned.
Still confused? Picture the Grand Canyon in your mind, it’s the perfect example to understand that water flowing over rock can do damage.
A liquid solution of copper sprayed on the top surface of the concrete interlocking pavers, will stop the growth of the pesky green and black organisms in their tracks since it is a natural biocide. The easiest way to apply the copper is to buy copper sulfate crystals which are available online, and the blue crystals dissolve readily in warm or hot tap water. Mix 1.75 pounds of copper sulfate in each gallon of water and apply the solution when the paving block is dry as a bone.
The problem here is that copper is a potentially toxic substance to clean an area where people, pets, and vegetation are and can be harmed by getting it on their skin, eating it, or absorbing it.
Also, copper solution only addresses the symptom, but neglects the underlying issue, and, by doing so, creating further problems or worse dangers.
We need to address the possible constant sources of moisture to the pavers, apart from rainfall, that causes them to never fully dry out and to have a recurring mold problem.
What Do We Recommend?
Our unsolicited advice for you to handle the mold problem in a way that is healthy to all living creatures and plants is as follows,
The first thing to look at is your drainage system because if moisture is constantly flowing towards these pavers, the ground underneath them is most likely constantly wet. Which means, paving tiles will never fully dry out and the mold will continue to come back no matter how or what you clean them with. You can try irrigate and install drains in your yard to easily solve this problem.
The other piece of this puzzle is sunlight. Is any sunlight getting to your interlocking concrete block? Is the area covered by trees or an overhang? If foliage and tree cover is the case, you might want to consider doing some landscaping or tree removal that give that area more natural sunlight. The sun’s rays are a powerful mold retardant. Sunshine will aid in keeping the interlocking bricks dry and will prevent future mold growth. If you have a retractable overhang, consider pulling it back during the hottest times of the day when the sun is most powerful, so that it can do its job on the pavers.
We also recommend using a laundry additive that can be used to remove mold as well. Take 1/3rd of the bottle in a one-gallon sprayer or put into a garden hose mixer and spray the entire area before allowing it to fully dry. Then, with the help of a scrubbing brush and some elbow grease remove any visible mold. Spray again and allow to air dry. If there’s an area with a large concentration of mold or algae, use the laundry additive undiluted with your scrub brush to remove what remains and to prevent further growth.
The laundry additive can be walked on with bare feet, you do not need to wear protective gear to apply it, and it’s safe for your pets too. The mixed laundry additive should last about 2 to 3 months.