Cinder Block

Previously Painted/Flaking or Peeling/To Be Painted/With Elastomeric

1. 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
  
  
2. Priming:
• After preparing the surface, apply exterior latex primer
• be sure any sources of moisture behind the substrate are eliminated
• do not use elastomeric coating over old oil-based paint
• use quality exterior latex primer that is recommended for masonry surfaces
• do not leave a primer unpainted

3. Painting:
   • use top quality exterior 100% acrylic elastomeric wall coating
   • apply two coats for maximum crack bridging and durability
   • apply at manufacturer’s recommended spread rate; for best performance, this will be 40 - 60 sq.ft./gallon to achieve a minimum dry film thickness of 7 mils per coat.

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