Home Improvement Stack Exchange is a question and answer site for contractors and serious DIYers. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

Does sealant like Thompson's WaterSeal slow the growth of moss on concrete? I live in the rainy Pacific Northwest and moss and mold are regular problems.

share|improve this question
up vote 3 down vote accepted

In a way it does. It's a lot like Rain-X makes water bead up on glass, masonry sealant will make the water tend to bead up and run off of brick and concrete. However, much like Rain-X, it wears out every once in a while -- probably more often in the PNW where it'll get wet all the time.

The moss grows because there's easy moisture to be found within and on top of the brick. However, the sealant won't prevent moisture that's deposited on the brick by fog / mist or dew from collecting -- all three things are common in the PNW due to the relatively high humidity. Therefore, it'll help a bit, but it's not a total or even ideal solution.

Although -- the Thompson's sealant is not the best on the market by far. Look at the Behr stuff.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.