What do I use to seal the outside cinderblock on house?

q what do i use to seal the outside cinderblock on house
How do i kill this mold in my house and keep it gone. This is in a closet under my steps
  5 answers
  • Vinegar will kill the mold, then I would set a fan there to completely dry the area out, it needs to be bone dry. Then you need to seal it with a Kilz or Zinsser product. You will need to paint both the wood and the cinderblock. Take this photo to a stand alone paint store, Sherwin Williams, Dunn Edward's, etc., and they will have everything you need. It is molding due to dampness and poor air circulation. Will need to be checked periodically.

  • Sharon Sharon on Mar 28, 2018
    You will have to address where the moisture is coming from. This might be adding a French drain outside to move the water away from your foundation. It could be addressing your gutter system and the downspouts to move water away from the foundation. You can waterproof the outside of the concrete with Drylok waterproofing.
    If there is a vent or basement window down there you can add a vent fan to expel the air so moisture doesn't build up.
    If that a dirt floor at the very bottom of the picture, that would also be a source of to address.
    There are mold abatement products that can be used to remove the amount on the blocks now, visit a home depot or Lowes. I recently used Concrobium in a spray can to treat my client's post-abated studs and concrete flooring prior to repairs being started.
    This guy has lots of French Drain solutions.... https://www.youtube.com/watch?v=RosQjZ3-Alo

    • Morgan Morgan on Mar 29, 2018
      Great reply. If you don't address where the moisture is coming from, all the rest - from spraying with vinegar and painting with Kilz or Zinser is just going to be throwing good money after bad.

  • Sparkles Sparkles on Mar 28, 2018
    flex seal?

  • Dee Dee on Apr 01, 2018
    after cleaning and finding source of moisture, I would stain with concrete stain and seal with Thompson’s water seal.