Wash and Scrape
Every exterior paint job should begin with a thorough washing to remove grime and mold. If not removed, mold will continue to grow under the new paint. A power washer does this effectively, but to prevent damage, you should set the pressure between 1,500 and 2,000 PSI and use a nozzle with a 15-degree or wider pattern. It can also help to scrub heavy mold with soap and water before pressure washing.
After the siding dries, go over it with a paint scraper to remove any peeling paint that the power washer didn’t remove. You may have to scrub some spots with a stiff-bristle brush (or a wire brush for masonry) to remove all the loose paint.
Protection from Overspray
It's important to wait for a dry, calm day to spray, but even in ideal conditions, overspray can settle on areas of the home you don’t want to be painted, unprotected plants, shrubs, and sidewalks. Cover them with plastic sheeting or drop cloths. Secure edges with tape to prevent wind gusts from lifting them. Masking the doors and windows is important, but don't overdo it. Overspray is easy to remove from glass, so you seldom have to entirely cover windows. Plus you don't have to bother masking trim that you plan to paint.
Prime and Paint
Although priming may seem like an optional extra step, it really isn't -- even if the existing paint is in good condition. Primer blocks stains, such as those from mold that you may not have entirely removed, and it increases the lifetime of the paint job. Choose a high-quality exterior primer and spray it at full strength. If you're changing the color of your house, tint the primer toward the new color to save on paint. Finish with at least two coats of exterior flat, satin or semi-gloss paint. Satin is a universal sheen that works on most surfaces, but wood siding often looks best with a flat finish. Choose semi-gloss enamel for the trim.
Exterior sprayers, such as the FLEXiO 990, consist of a pump that feeds paint from a can or container that stays on the ground, to the handheld sprayer. Because the two are connected by a hose, test the reach of the hose before you climb on a ladder to spray the upper part of the house -- you may have to reposition the paint can. Start spraying at the top of the house and work your way down. Position your ladder with both of its feet securely planted on a level surface and hold on tight each time you press the sprayer trigger. The sprayer can produce a backward force that may surprise you if you aren't prepared.
Painting your home's exterior may require some effort, but the results are always worth it. Enjoy!