Wednesday, May 5, 2004

Pressure washing your home: What to know before you buy

Proper maintenance of the exterior of your home will add value and years. However, most people never think about pressure washing until that nasty black Georgia mildew has already formed on your gutters and overhangs. In this article, we discuss the four major areas of your home (home, gutters, driveway, and decks) that can benefit from pressure washing and some things you need to know as you decide what to wash and whether to do it yourself or contract the work out to a professional.

• Houses. The home is the most common thing that people think about when someone mentions “pressure washing.” That’s because your home is where mildew develops the quickest, and is the most visible from the street. Even “maintenance free” exteriors like vinyl siding will develop unsightly mildew and algae every year or two.

House washing is something that you can do for yourself, but you should do so with great care. Slippery bleach, soap, water, and ladders together create an serious fall hazard. Also, chlorine bleach is required to kill mildew, but atomized bleach droplets from a pressure washer can cause severe damage to your eyes and lungs. Also, consumer pressure washers require very high pressures to blast away the mildew. This has its own risks as forcing water into siding materials can cause irreparable damage. Also, high pressure water can easily bypass window seals, gaps in the siding, etc. and cause serious water damage inside your home.

A qualified professional will use a special mixture of chemicals and high-tech equipment to clean your home at low pressures without water intrusion or damage to your plants. When interviewing house washing professionals, ask them what chemicals and pressures they will use. If you have a unique siding like cedar or masonite, ask them how they will get it clean without causing damage. If they are hesitant to discuss their chemicals, equipment, or process, be wary. And always use a professional who is licensed and insured. A typical home cleaning will run $125-200 and take 2-3 hours to complete.

• Gutters. The black streaks that form on your gutters are a type of oil that rainwater leaches out of your shingles. There is no way to prevent these black streaks from forming, but you can slow the process down by keeping your gutters clean to minimize the amount of water flows over the outside of your gutters. These oil streaks are very difficult to remove, and the chemicals required to remove them successfully are not available to the general public.

Fortunately, a regular cleaning by a qualified pressure washing contractor will remove them quickly. However, if you have ignored your gutters so long they are already a consistent shade of gray be aware that your first cleaning may require tedious and expensive hand scrubbing.

• Driveways. Over a period of years, your new driveway will fade from a bright white to a dingy blackish color. This darkening is a combination of mildew, auto exhaust, and tire rubber and grime. Consumer grade pressure washers will remove this dirt very effectively, although doing so is quite a slow and tedious job. This built up grime causes no damage to your drive and can be left alone without worry. However, cleaning a driveway has a dramatic effect on the curb appeal of a home and should be seriously considered if your home is up for sale or soon will be. A typical driveway cleaning costs $75-90 and takes about 1-2 hours.

• Decks. Pressure washing wood without causing damage takes skill, experience, and the right tools. The last place to learn how to use a pressure washer is on your wood deck. If you have no experience working with a pressure washer, you can do a great deal of damage quickly. Professional deck washing is not cheap, but if you consider the years it adds to the life of your deck it is a great value. However, if you are the do it yourselfer type who insists on pressure washing your own deck, here's a few things you can do to avoid causing damage.

Don’t use chlorine bleach on wood. Chlorine bleach is a popular deck cleaner because it is cheap and it brightens the appearance of the deck quickly and easily. But like most things that appear too good to be true, it is. Chlorine bleach destroys a part of the wood called lignin that is responsible for holding the wood together.

If you have ever pressure-washed your deck before and had to deal with rinsing off squishy pulp, that’s the lignin that has been eaten away by the bleach. It’s also years of deck life down the drain. If you didn’t notice the pulp, you may have noticed that your deck was “fuzzy” after it dried. That fuzz is deeper layers of wood fiber that are no longer bound together.

Bottom line: Unless you like replacing your deck relatively often, don’t use cleaning products that contain chlorine bleach (sodium hypochlorite) on wood. If you’re hiring a professional find out what they are using and make sure that they are not using chlorine bleach.

Spend money on the proper tools. Cleaning wood without causing damage requires a high volume of water (4 gallons/minute or more) at a relatively low pressure (around 800 psi). Most consumer grade pressure washers are limited to about 2 gallons/minute at full pressure and produce less than one half gal/min when dialed down to 800 psi. A good commercial grade pump and proper set of nozzles will provide the water flow to do the job faster, easier, and with much less damage.

Don’t use a rotary “turbo” nozzle on wood. A turbo nozzle is a takes a very small intense stream of water and rotates it very quickly to create a much wider cleaning area. They are standard equipment on almost all consumer grade pressure washers because these units lack the power to deliver a wide cleaning fan at useful pressures. The problem with turbo nozzles is that although they may give the appearance of a wide fan, they are actually a tiny jet at thousands of pounds of pressure. And that type of intensity can literally tear the outer layers off your deck and/or leave permanent scars in your wood. Turbo nozzles were designed for blasting dried mud off bulldozers and other heavy equipment. Leave them in your toolbox for the next time you need to clean your wheelbarrow and shovels.

Buy a breathable sealer. Protecting your deck for harmful UV rays will add tens of years to its life. However, polyurethane, paint, and other coatings that create a film on the woods surface trap moisture in the wood and greatly accelerate deck rot. Select a quality stain/sealer such as those offered by ReadySeal, Compton’s, or Olympic. These products will protect your wood while allowing it to cast off excess moisture and preventing premature wood decay.

Pressure washing can be a fast and inexpensive way of improving the looks and value of your property. Whether you do it yourself, or contract it out to a professional, a little bit of knowledge can make the process much easier and less expensive.

— Philip Doolittle

(Philip Doolittle is the owner of PowerHouse pressure washing. PowerHouse pressure washing services Fayette county and surrounding areas and can be reached at 770-460-0469.)