As any painter will tell you, prep work is just as important -- if not more important -- than the paint application itself. If the paint on your house is chipping or peeling, it needs to be scraped and sanded smooth before applying a new finish. In most cases, you won’t need to remove all the existing paint, but scraping, sanding, patching, caulking, and priming are critical steps that take place before the start of most exterior painting jobs.
To begin, move everything out of the room. Every painter we spoke with had a horror story about the time he didn't follow Rule No. 1. Bigger pieces of furniture can sometimes be left covered in the center of larger rooms, but if you are repairing drywall, says Chris Span, of Span's Quality Painting in Mobile, Alabama, "Take everything out. Drywall dust goes everywhere." Remove doors, light fixtures and hardware, and label everything with masking tape. Also, invest in drop cloths. "It's surprising how well a few drops of paint can cover a floor," says Rich Maceyunas, of Maceyunas Painting and Wallpaper in Waterbury, Connecticut. Buy high-quality drop cloths, such as canvas or paper-backed plastic. (Paint soaks right through lightweight fabrics and bedsheets.) Plastic sheeting works, but it's very slippery and doesn't absorb drips.
Sorry it is difficult to trust almost anyone in the trades. It is easier to do the work myself and not deal with strangers in and around my house. When I have to hire someone I tell them up front that I'll be checking every detail, pay extra to purchase the materials myself, and if they don't want the job - well good! I always fine someone who will work with me as I pay a bonus for that.
Depending on just how dirty the outside of your house is and on the house's size, there are two ways to approach this job. If you live in an average-size house, use a garden hose with a carwash brush attachment to bathe the big areas. For caked-on dirt, use a scrub brush or a sponge and a pail of warm water with a good, strong household detergent in it. Work from the top down, and rinse all areas where you scrubbed with water.