Exterior/Stucco/Previously Painted/Sound & Continuous/With Elastomeric


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

  • 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
  • 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; wall and chimney caps must be sound and continuous; chimney flue should have rain cover
  • 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 stucco that could have caused the efflorescence
  • 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 porous areas


b. Priming:

  • priming is helpful but not necessary if existing paint is latex in excellent condition, unless specified by the elastomeric coating manufacturer
  • be sure any sources of moisture behind the substrate are eliminated
  • prime if there is any sign of efflorescence (remove it first) or any loose paint (remove by wire brushing)
  • use quality exterior latex primer that is recommended for masonry surfaces
  • do not use elastomeric coating over old oil-based paint
  • do not leave a primer unpainted

 

c. Painting:

  • use top quality exterior 100% acrylic elastomeric wall coating
  • apply two coats (or one coat if old coating is an elastomeric also, and is in good condition)
  • · 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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