Tips to Paint Like a Professional; stucco
Preparation for the painting of residential exteriors begins with a decision whether or not to pressure wash. This will be determined by the amount of dirt, the presence of mildew or chalking, and how much old paint needs to be removed. There is no simple formula for deciding.
The advantages of pressure washing are that the surface will be clean and the new application of paint will adhere better, mildew can be easily removed in hard to reach areas such as the eves, and old peeling paint will come off quickly (areas of peeling paint will still require additional hand scraping). A particular problem for Pacific Palisades homes is salt residue can build up under the overhangs and areas not washed by the rain. This can only be removed by a powerful stream of water.
Machines for pressure washing are available at many equipment rental companies. They are not difficult to operate, but extreme caution is advised. They generate pressure at the nozzle of 3000 psi (pounds per square inch) enough to do serious damage to the building, plants, or people. Some are available with a chemical injector that allows for the addition of bleach or detergent. This is a good idea if the surface is extremely dirty or has a lot of mildew. It is advisable to have a helper inside of the house with a towel to watch for leaks around the windows and doors as you are washing.
One more word of caution, use as little water as possible around bare wood, it will need to thoroughly dry before priming or painting.
Once the washing is complete you can begin the necessary stucco repairs.
Stucco that has separated from the lath wire or is crumbling must be removed. Break it out to the point where a sound surface is intact. Once removed determine the cause of the problem. Some causes can be; a leaking pipe, unsealed stucco exposed to sprinklers, structural movement, or settling. Larger holes require a lath wire backing attached to the studs. Use a wire brush to remove any loose material, wet the edges of the old stucco (to prevent moisture from being drawn out of the new application) and apply a concrete bonder to all areas to be patched.
The next step in the process is the application of the first coat of stucco. Mix according to directions and spread with a trowel or large putty knife to just below flush. Allow to set and follow with a thin second coat that should be immediately worked with a float or sponge trowel to match the existing wall texture.
Rapid drying stucco compounds are now available that can be re-coated or painted in as little as one hour. Larger cracks over one eighth inch will need the same treatment as described above. Smaller cracks can often be filled with a textured caulk. If there are many hairline cracks, the use of a “high build” Elastomeric paint will be sufficient to fill them.
After the proper drying time the stucco will be ready for paint. Primer is not necessary but an additional coat of paint should be applied to any patches or caulked areas.