Have you observed patches turning dark on your driveway and green growth on your sidewalks?
Houston’s humid climate creates ideal conditions for the growth of algae and mold alike. These stains not only affect the appearance of the surface but may also cause slipperiness. This algae is also an allergen for many, and when you walk on it, you track it into your home.
Fortunately, proper concrete pressure washing can restore the beauty of a driveway. The following are five tips that one could use to clean up the growth in driveways without affecting the concrete.
1. Identify Mold and Algae Before Washing Concrete
Dark spots can also point to other things than just algae growing. They might indicate things like lichen growth, fungal colonies developing, or runoff from an algae-covered roof from downspouts that empty onto the driveway.
Algae is a type of bacteria. However, when they process food, they excrete the dark material we often call “algae staining”. Algae thrive in damp conditions and locations where dirt and water are frequently present.
Algae do best on surfaces that absorb water, are porous, and flat. Driveways and parking lots are ideal for algae to thrive. Routine cleaning is the solution to keep those surfaces safe and maintain the curb appeal.
2. Select the Suitable Concrete Cleaning Solution
Pressurized water does not always remove organic growth effectively.
Different types of contamination and concrete require different concrete-compatible cleaning solutions. The solution will contain necessary algaecides or sodium hypochlorite in order to clean biological growth.
There are other algaecides available, but sodium hypochlorite is the most economical choice to remediate the algae.
Always pay attention to the directions for use and try to prevent damage to any plants, and also do not mix cleaning agents.
In addition, professionals will likely also use hot water to clean with, which can reduce the surface tension dramatically, reducing the chemical usage.
3. High Pressure or High Flow: Gallons per Minute
Pressure does not always mean better quality of concrete cleaning. However, high flow rates are where you greatly increase your cleaning potential.
Most professionals work at a pressure range of 2000-2500psi, but flow rates of 8GPM or more. Most home pressure washers boast 4000 or more PSI, but rarely beyond 3-4GPM.
Pressure washers at 3000 PSI can damage concrete, and at 4000 PSI will damage concrete. Depending on the quality of the concrete, PSI rating, and the surface condition, a combination of algaecide application, high flow, lower pressure, and surface cleaner employment is the proper way to best use pressure washing to clean concrete.
4. Surface Cleaners vs Wand only?
Inconsistent cleaning results cause visible streaks on the surface of driveways. This can happen with surface cleaners as well as wand cleaning. Achieving proper results from a surface cleaner requires matching the surface cleaner size with the pressure washer.
On the other hand, this cleaning step rinses away any dirt that remains after you are done. Before proceeding with your plan for pressure washing on concrete, make sure to double-check if there’s anything else needed.
5. Prevent Mold and Algae from Returning
Even if you manage to remove all the mold by cleaning it up properly, there’s no guarantee that the problem won’t recur because of the moisture.
Your best defence is a good offense. Keeping the water out of the surface is the best way to slow down the algae growth. This requires sealing the surface. There are a number of ways to do this for driveways.
Products that penetrate the concrete, provide a water barrier, and allow the concrete to breathe and release vapor pressure from groundwater are the best choices.
Trimming trees and landscaping to reduce shade and leaves, nuts, and berries from dropping on the driveway can help keep the driveway looking better longer.
Adjusting irrigation so the driveway is not being regularly irrigated or producing runoff that sheds across the driveway will reduce algae growth.
Regularly cleaning. Scheduling annual cleaning can help keep the driveway or parking lot from ever looking really bad.
Frequently Asked Questions
Is pressure washing safe for concrete, or should I use soft washing?
Pressure washing can damage your concrete surfaces if you are not careful. Soft washing with low pressure and chemicals would be better. If you have delicate or worn-out concrete, soft washing with chemical cleaners may work better than pressure washing.
Can pressure washing damage concrete?
Yes. If you are exerting excessive pressure, using concentrated spray, or misusing equipment, then there will be permanent damage to the surfaces.
What PSI is best for pressure washing a concrete driveway?
2,000 – 3,000 psi is considered an average working range that will work well with concrete in good condition, but it really depends upon the age, finish & condition of your surface to set your perfect parameters.
What is the best concrete pressure washer solution for black mold and algae?
Using a concrete-compatible cleaner that can treat organic growth is better than just using water. Follow your manufacturer’s guidelines for diluting and applying their product.
How often should I pressure wash concrete?
You might consider concrete pressure washing once annually as a good start, but you will likely need to clean shaded or frequently wet sections more often.
How do I find a reliable concrete pressure washing company near me?
To find a reliable concrete pressure washing company near you, search for “concrete pressure washing near me” to see their reviews. Before hiring them, make sure they have proper insurance, experience, and a formal written estimate.
Restore Your Concrete with Cypress Curb Appeal Services
Tired of looking at stained driveways and slippery walkways? Cypress Curb Appeal Services offers the best concrete pressure washing solution for all of Cypress, Cy-Fair, and Northwest Houston.
Our concrete pressure washing company is here to help revitalize your driveway, walkway, patio, and other surfaces around your home.
Call (281) 801-4580 today or visit Cypress Curb Appeal Services to request your free quote.