James Dulley
Deck Maintenance Basics

Deck Building Basics

Deck Cleaning and Treating

Power Washer Basics

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People often ask me what I use at my own home. I use the new Craftsman Dial-A-Cleaner pressure washer. It has four built-in containers to make it simple for switch among various cleaning tasks.

Recommendations -


The minimum pressure you'll need in a power washer for cleaning decks is 1500 pounds per square inch (psi). Either hot water or cold water power washers may be used. Many deck restoration contractors recommend using cold water power washers in the 2800 to 3200 psi range. If you choose a hot water pressure washer you will need between 2000 and 2800 psi. Hot water power washers may also be used to melt grease and chemicals.

Nozzle Tips

There are generally 4 tip sizes used for power washers:

0· — Do not use for wood. The spray pattern is a concentrated straight stream that will damage wood.

15· — Use for tough cleaning jobs. This is a good choice for deck cleaning.

25· — Use for modest cleaning jobs.

40· — Use for light cleaning jobs.

You want to use the highest tip size that will get you the desired results. The smaller the tip size the more careful you must be not to damage the surface.


A good commercial grade power washer in the 2800 to 3200 psi range will generally have a 9 to 11 horsepower motor. Honda and Tecumseh engines have high performance ratings.


Power Washers generally come with 50 to 100 feet of high pressure hose. If you need to get the machine closer to the surface to be cleaned, it's usually best to add more supply hose. Supply hose should be 5/8" garden hose. You will lose about 100 lbs. of pressure for every 50 feet of high pressure hose.

Water Supply

Most power washers require 3 to 5 gallons per minute of water supply to operate. Know what the requirement is for your unit. Always make sure you have enough water pressure to supply your power washer. Water pressure is not generally a problem with most city water systems.

Homes on well water will sometimes not have enough pressure. If you are in rural locations, be sure the power washer you will be using will operate on the average water pressure in your area. A good way to check water supply is to try and fill all, or most of a 5 gallon bucket from a faucet within one minute.

Power Washing Techniques

There is a definite technique for power washing. If not done correctly, you can damage or scar wood. The best way to learn power washing techniques is to practice on old boards. The wand should always be kept in motion when it is close to the wood. Stopping the wand while still spraying water will scar wood. To avoid scaring, arc the wand up and away from the surface at the end of each stroke.

A power washer with a 15· tip will clean a strip about 4 inches wide when held about 6 inches above the wood. Always wash with the wood grain. Becoming adept at power washing takes a little practice before you find the best way to clean the different surfaces on a deck.