The most lasting and cost effective way to change the color of stucco is with paint. With your full attention on the details, from surface preparation to applying a high quality finish paint, the new look and color of your exterior stucco can be virtually maintenance free for many years.
Quality and craftsmanship is always in the details. This starts with proper surface preparation and any needed repairs. Then continues with choosing and applying the best primer and paint.
All masonry surfaces need to be fully cured before any painting can take place. New exterior stucco should be allowed to cure for a minimum of 60 days.
Before any preparation can begin take a good look at the entire surface. Pay attention to peeling paint, rust stains, efflorescence deposits and any areas needing repair. Peeling paint along with stains and efflorescence deposits can indicate water damage. These areas will require closer inspection after pressure washing.
Efflorescence deposits are a power that forms from water migrating through the stucco. This water picks up alkaline salts and deposits them on the surface or behind the paint film. A scrub brush and masonry cleaner might be needed for heavy deposits.
Pressure Washing Stucco
The preparation begins with a thorough washing to remove all dirt and dust. Pressure washing can be a delicate operation. Stucco is a relatively soft masonry coating and can be easily damaged by high-pressure water. Use minimal pressure, 1200-1500 psi and a wide spray tip.
Caulk and Sealants
Applying sealants to all cracks and gaps is very important and will drastically affect how long the paint job lasts. Water must be stopped from penetrating beneath the paint finish. The best and most appropriate sealant is an elastomeric caulk. With excellent adhesion and elongation characteristics this sealant will last a long time. Apply all caulk after the stucco is properly primed for the best performance.
Seal around all openings and penetrations. This includes windows, doors and wood trim. Other areas are dryer vents, any plumbing penetrations and at the wall to the soffit.
The most common repairs are large cracks, damaged corners and small areas of missing stucco.
Cracks – Non-structural cracks will always occur on masonry surfaces. They can either have a random distribution or occur in large numbers. These cracks can range from hairline to 1/4 inch wide. Caulk can be effective on small tight cracks, but will fail when applied to large cracks with a lot of movement. A better alternative is to use a brush grade elastomeric sealant. This thick sealant is available with or without texture to help it blend into the surrounding surface. Apply two coats; allow each coat to dry completely.
Damaged Areas – Any loose stucco must be removed and repaired. A professional contractor who can match the existing texture should repair large areas. Smaller areas can be repaired with specialized patching compounds. The basic steps are very easy. First chip away all loose material. Now rinse the area with water using a wire brush to remove any remaining powder or grit. The patching compound can be applied after the area has dried.The best patching compounds are a powder mixed with water. The first application will smooth the area and level it with the existing finish. The second application is to provide the necessary texture matching the surrounding stucco. Matching any texture is extremely difficult. Most likely the patched area will a little different.
Choosing Primer and Paint
An acrylic masonry primer is the best for whole house priming. For spot priming an exterior all-purpose acrylic primer can be used.
There are several considerations when choosing masonry paint.
Ability to breath allowing internal moisture to escape and still be resistant to external sources of water.
Flexible – Move with the house without splitting at any temperature.
Bridge small cracks. Removing these unattractive non-structural cracks.
Resist dirt pick-up and mildew growth.
Be resistant to chipping, chalking and peeling for maximum longevity.