How to Remove Mineral Deposits and Keep Your Customer Happy

One of our contractors, we’ll call him Sam, called recently to ask about white spots on the driveway he had recently stained and sealed. Needless to say, his customer was not happy.

Sam was relieved to find out the problem wasn’t serious and the solution was easy.

So, what caused the problem, and what should you do if you find yourself in Sam’s situation?

According to Chris Mirabal, our Senior Tech Advisor, the problem is generally caused by water droplets from a sprinkler or irrigation system landing on the concrete. As moisture from the droplets evaporates, a mineral deposit is left behind in the form of white spots.

Is the problem going to rear its ugly head every time it rains?

No, we don’t see the same effect from rainwater since it is “soft” and doesn’t become “hard” until it picks up calcium or magnesium ions as it passes through the soil and bedrock. Groundwater is the culprit.

To fix the problem:

  1. Mix 1 part white vinegar to 1½ parts water in a pump-up sprayer.
  2. Wet down a workable area with the vinegar/water solution and scrub. (The vinegar solution can kill adjacent grass, so use it carefully.)
  3. Pressure wash.
  4. Blow dry the area with a high-power leaf blower. (Since you’re using “hard” water from the water supply to power wash, it’s important to avoid allowing the wash water to dry, thus creating new spots.)

Once you’re finished, take time to talk with your customer about adjusting the sprinkler system so that it doesn’t spray the concrete. Not only will he avoid the problem of mineral deposits, he will also reduce his water costs while protecting water as a natural resource by using it more efficiently. That’s a win-win for everybody.