Simply Follow Your Hose on the Road to a Cleaner Exterior

Power washing your house every year with a high-pressure water spray can’t only keep it looking good but also can cut the need to repaint as often.

Power washing aluminum, steel, vinyl or wood siding removes grit that grinds away the surface like sandpaper when it’s agitated by wind or rain. Power washing is also a good way to prepare a house surface for repainting.

If you’re lucky, once the siding is clean you may find that you don’t need to paint after all.

If your house does need repainting, a thorough power washing removes not only dirt, mildew and moss but also peeling, flaking and chalking paint. You can wash even a large house in a single day.

Power washers are available for rent, usually by the day, from tool rental stores and some paint specialty stores. Make sure someone demonstrates how the equipment works and answers all your questions before you leave the store.

Power washers are rated by the pressure of their spray, measured in pounds per square inch (psi). For the average house, a rating from 1,200 to 2,500 psi, compared with about 60 psi for a garden hose, is sufficient. Less than 1,200 psi won’t do the job effectively, and more than 2,500 psi could do damage if not handled skillfully.

Power washing with clear water usually does the trick. To remove chalking, moss or mildew, you’ll probably need a general cleaning agent, available where you rent the equipment.

Nozzle design and spray width are important. The recommended nozzle sizes are 15, 25 and 40 degrees with the 15- and 25-degree nozzles the ones that achieve the best results.

Power wash from the bottom up, to prevent dirt and the cleaning agent from running down onto the unwashed surface and leaving streaks. Rinse from the top down, to thoroughly wash away the cleaning agent and dirt and avoid leaving streaks.

Other tips:

* Always wear safety goggles to protect your eyes from splash back or accidental direct spray.

* Make sure all windows are closed tightly.

* Turn off the power to light fixtures and electrical outlets at your home’s main service panel. Cover them with plastic bags or film secured with duct tape.

* Place dropcloths over plants and shrubs. Move lawn furniture away.

* Don’t wash when it’s windy.

* Keep the nozzle 10 to 12 inches from the surface, at about a 45-degree angle.

* Use caution when cleaning aluminum or steel siding. A power washer can bend sections--even blow them right off the house.

* Windows can break if you spray directly at them.

* Don’t spray under the laps of horizontal siding; it can lift them. And don’t spray directly into crawl spaces or gable-end vents.

* Don’t let children operate a power washer.

* When operating, never put your hand near the tip of the wand or aim it at a person or animal. The water will penetrate and cause severe injury.

* Keep at least 10 feet from power lines.

You’ll be working with a lot of water pressure, but with a little practice you should be able to control the wand. Keep in mind that a telescoping wand--which you’ll need to reach higher floors--can kick back 3 to 4 feet each time you depress the handle.

You will probably tire from fighting the water pressure. When you do, take a break.