Pros and cons of power washing

It's not just national monuments like Mount Rushmore than could benefit from a good power wash every now and then.

Is there grime on your siding that good old-fashioned elbow grease won't take away? Stains on your concrete driveway? Is the deck looking dirty?

Power washing or pressure washing - the terms are used almost interchangeably - might be an option.

"People find it so powerful," said Ken Collier, editor-in-chief of The Family Handyman magazine. "It's so fast and it's so liberating."

You can hire a pressure-washing company, or do it yourself. Machines come in electric and gas models, and can be rented or purchased.

Are there risks?

"Too much pressure on vinyl siding or stucco can cause damage to the surface," said Doug Rucker, owner of Clean and Green Solutions in Kingwood, Texas, near Houston. "The same thing with concrete cleaning."

Similarly, excessive pressure on a deck can tear up the wood. "When we're cleaning wood decks, we're using what we call low pressure," he said.

When you're cleaning the exterior of the house, window and door seals need to be protected to prevent leaks. Windows could also break if you inadvertently hit them with the same pressure you're using for the rest of the house.

And, there's always the risk of working on ladders with a machine that has recoil. "It's something where ladder safety is very important," Collier said.

Homeowners also need to be aware of overhead power lines.

Still, many people decide to do the work themselves. Home supply stores offer an array of pressure washers; prices range from about $100 to more than $1,000.

Collier said most of the skill in using a power washer lies in applying the right pressure and tip. "It's like anything else - you have to learn how the tool operates," he said.

Gas pressure washers tend to be more powerful, noisier, heavier and more expensive than electric ones. Manuals that come with the units should explain what types of job they're good for.

If you decide to rent a power-washing machine, Collier advised, "Have a job in mind, ask what tip you need and if there's an additive that will help with the cleaning."

And don't forget the prep work. "The finished product is only going to be as good as the preparation you did," said John Nearon of Exterior Wood Restoration in Cicero, Indiana.

People unaccustomed to such work might be advised not to try it themselves, Collier cautioned. "Lots of people do it themselves, but it's also something that for most people it would be a hire and done," he said.

Hiring a contractor to power wash a home could cost 12 cents to up to 20 cents per square foot, depending on the location and surface,said Rucker, who also provides training for power washers. Before hiring a company, ask questions:

• Insurance. Is the contractor insured to cover any damage or injury that might occur when cleaning? Don't be afraid to ask for a copy of their insurance certificate binder, Rucker said.

• Training. Do workers get continuing education to keep their training up to date?

• The process. "Talk to them about how they're going to clean it, what kind of process they're going to use, down to the products they're using," he said. In the Southeast, for example, he said bleach is used to kill mold and mildew and keep it away longer.

• Safeguarding landscape. What will they do to protect trees, shrubs or other plants around the house or property being cleaned? Rucker said wetting down plants and keeping them watered is important. If you cover them, he said, do it only for minutes at a time.

Power washing isn't just for big projects; it also can be used for things like patio furniture and cars.

Collier likens the experience of using a power washer for the first time to switching from a hand lawnmower to a gas, self-propelled one. "It's kind of a momentous thing," he said. "You can't say the same thing about most tools."