Pro Tips for Exterior House Painting
Surface prep—If the siding may be manufactured from cement asbestos, make no attempt to scrape, sand, wire brush, power-wash or otherwise disturb the surface. Instead, apply a solvent-based or latex sealer or primer recommended for exterior masonry surfaces, and once thoroughly dried, proceed with painting. If the siding has previously been painted and lead is suspected in the paint, contact a contractor qualified for lead assessment and abatement.
Otherwise, prep the surface of fiber-cement by removing any loose or peeling paint by gently scraping or abrading with a wire brush. If efflorescence is present, scrub it off and eliminate any water source that may have caused it. Treat mildew with a bleach mixture and rinse with plain water.
Priming—For fiber cement, priming is helpful but not necessary if the existing paint is in good condition (unless specified by the paint manufacturer). If you had to remove efflorescence, coat the siding with a quality exterior latex primer that is recommended for masonry surfaces.
Painting—Use top-of-the-line exterior 100-percent acrylic latex house paint in a flat, satin or semigloss finish; or use quality latex masonry paint.
Surface prep—If the stucco has previously been painted and you suspect lead in the paint, leave it alone and call a contractor. Otherwise, remove all loose or poorly adhering paint by scraping or using a wire brush, or power-wash with plain water, taking care not to drive water into cracks or porous areas.
Remove any efflorescence and eliminate any water source that may have caused it. Remove mildew with a bleach solution and rinse thoroughly.
Priming—With stucco, priming is important to ensure maximum durability and resistance to efflorescence, alkalinity and mildew. Use quality exterior latex primer that is recommended for masonry or stucco.
Painting—If you’re repainting the stucco, use top-of-the-line exterior 100-percent acrylic latex house paint in flat, satin, or semi-gloss finish. Old, unpainted stucco can also be finished with a top-quality exterior 100-percent acrylic solid color stain that is recommended for masonry or stucco surfaces. Some solvent-based acrylic masonry or concrete stains may be applied to stucco without priming, but you should consult the manufacturer’s directions.
Surface prep—If the existing house paint has no lead content, remove all loose paint by scraping or by wire-brushing, working with the grain of the wood. For wood shakes, use a wire brush with vertical strokes. (Note: when using a steel brush on cedar, remove all bits of steel wire to avoid discoloration.) Feather-sand the rough edges of the remaining paint. Refresh the surface of exposed wood by sanding with medium grit (#120) paper. If gloss or semigloss paint will be used, follow by sanding with fine grit (#220). Dull any existing glossy paint by sanding with a fine abrasive.