For bigger houses or for faster work on smaller ones, rent a high-pressure spray cleaner. This device attaches to your home's water-supply system and puts out a jet of water at a pressure of about 600 pounds per square inch. It is equipped with a handheld wand tipped with a trigger-activated nozzle. The pressure is high enough to dislodge not only stubborn dirt, mildew, stains, and dried-on sea-spray salt, it's enough to remove peeling paint. In fact, if the jet nozzle is held too close to the surface it can even peel off perfectly sound paint, split open shingles, and drill a hole in siding. So follow the manufacturer's directions and wear goggles and protective clothing.
Painting the exterior of your house is about more than just curb appeal. The right paint provides a protective layer between your home and the elements, preventing costly damage to siding, trim and other materials. With proper prep work and the right paint for the job, you can expect your home’s paint job to look great and stand up to the conditions for several years.
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.