Brick Paver EfflorescenceIn the Spring, I will receive calls from customers with brick paver patios, walkways, driveways, or porches that are experiencing a whitish residue on their paving stones. The name for this occurrence is Efflorescence.
Efflorescence is the simple process of moisture evaporating or being drawn out and drying from a cement or clay product, such as, a high density concrete paver, and leaving a salt residue or deposit on the surface. For the real technical buff, here is the Wikipedia definition for Efflorescence.
This is a natural process of most cement based products and for brick pavers. This process may be slower for a paving stone due to its high density (psi). The most obvious occurrence that most of us see on a daily basis, is when a new concrete drive or walk is poured. For the next week or two, you will notice that while the concrete cures, it is very whitish in appearance. Then eventually the concrete will appear it's natural gray hue over time. This is the biggest reason why brick paver manufacturer's recommend not sealing your newly installed paver patio,walk,or driveway until a minimum 60-90 days. I advise to wait 6-12months to make sure any & all efflorescence from the paver has diminished. Especially if you plan on sealing your paver patio or walk.
This first step in removing Efflorescence is to just let it wash away naturally! Yes, rain & time will help wash away any mild case of efflorescence. If your efflorescence does not wash away naturally, the next step to try is to brush off the paving stones while dry. Use a stiff bristled brush but not steel bristles or anything that will scare or scratch the brick pavers. This will hopefully help break up or reduce the amount of residue to let the efflorescence wash away naturally.
If your Efflorescence is severe or persistent, it will be time to use a more aggressive approach. Most brick paver manufacturers offer efflorescence cleaners for their respective paving stones and retaining walls. paver cleaners generally have a high strength oxidant to clean your brick paver patio, walkway, or driveway without having to use any acid based chemical like muriatic acid.Follow the instructions very carefully. It is a very scary thought when the public starts using phosphoric acid based products. Leave that for paver cleaning professional.