Cinder Block

Previously Painted/Flaking or Peeling/To Be Painted/With Conventional Paint

a. Surface Preparation:

NOTE‚ If lead is suspected in the paint, do not attempt to scrape, sand, power wash, use heat gun, etc., which might put lead into the environment, but rather contact a contractor qualified for lead assessment and abatement

• remove all loose or peeling paint by scraping and wire brushing; wear eye protection, gloves and a dust mask; or by power washing with plain water, taking care to not drive water into cracks or mortar joints
  
• if efflorescence is present, remove by hand wire brushing; wear eye protection and gloves; try to identify and eliminate any source of water from behind the block that could have caused the efflorescence
  
• scrape out and widen any cracks; brush out dust, and seal with 100% acrylic or siliconized acrylic caulk; make second application in several hours if needed; check mortar joints carefully and repair or re-point as needed; wall and chimney caps must be sound and continuous; chimney flue should have rain cover
  
• treat any mildew with a 3:1 water:household bleach mixture, leaving it on for 20 minutes and adding more as it dries; wear eye and skin protection; rinse thoroughly
  
• remove dirt, chalk, dust, residual particles of paint, unbound sand, treated mildew, etc. by scrubbing with detergent and water, and rinse thoroughly; or power wash with plain water, taking care to not drive water into cracks or mortar joints

b. Priming:

• after preparing the surface, apply exterior latex primer for best durability, uniformity and resistance to efflorescence and mildew
  
• use quality exterior latex primer that is recommended for masonry surfaces
  
• do not leave a primer unpainted

c. Painting:

• use top-of-the-line exterior 100% acrylic latex house paint in flat, satin, or semi-gloss finish, depending on appearance desired; or a quality latex masonry paint