The Pressure to Wash Before You Paint

It's that time of year again – time to start thinking about what your house is going to look like in the spring when the grass is growing, the flowers are blooming, and the sun starts spending more time in the sky.

We spend much of the winter stuck looking at the inside of our house, but now we need to consider what people see when they're looking at the outside. Whether you need to do some painting or even just clean off a layer of dirt, a thorough pressure washing is a great place to start.

If you've never used a pressure washer before, it can be a little intimidating. After all, the average pressure washer harnesses a lot of power. It can strip off dirt and paint from wood, metal, bricks... almost anything really. You do need to be careful, but if you follow a few easy guidelines, you'll be fine.

• Keep the kids away. The allure of playing with water in the yard is a strong one, but pressure washers can generate tremendous force and should be used with care.
• Read the manual. All pressure washers are different, so be familiar with the one you're using.
• Know how to shut it off quickly. The spray wand should have a trigger that you can quickly release to stop the flow of water, but you should also be able to quickly shut the machine off if needed.
• If you're using an electric model, make sure it's grounded – if it has a 3-prong power cord, plug it into a 3-prong outlet – and never spray in the area where the machine is plugged in.

Tips on tips

Without the nozzles or tips to concentrate and direct the water, your pressure washer is just a fancy water pump. Some models include a variety of nozzles and some do not, so if you need to buy a nozzle, the first step is to decide what you're going to be cleaning. Types of nozzles can vary, but most of them will be labeled by angle and fall between angles of 0° and 40°.

• Zero degree - As it implies, this nozzle shoots water straight out, but at a much higher velocity. This one should almost never be used on woodwork as it could easily damage the wood. A zero degree nozzle is best used in removing grout from between bricks or stones.
• 15 degree – This tip is designed to act like a scraper or chisel. This is the nozzle you are most likely going to need if you want to strip paint from wood or metal.
• 25 degree – This tip may remove some loose paint, but it is primarily intended for cleaning. If your existing paint is in pretty good shape, but is just dirty, you should probably clean it with this nozzle before repainting.
• 40 degree – The 40 degree nozzle is more of a rinsing tip than a cleaning tip, but is particularly useful when you need to clean windows or other delicate features.

Before you get started

Once you've got your pressure washer, you know how to use it, and you've figured out what nozzles you need, it's time to take a look at your workspace. These are fairly common sense guidelines, but it's a checklist worth looking at before getting too far along.

• Clear the space around where you are cleaning. Cut back any shrubs, remove any hanging plants, and take down any exterior decorations that could get damaged. Close all of the windows. Remember, you will be spraying a lot of water, so you might consider covering delicate plants and flowers.
• Determine if you need a ladder. For most pressure washers, you should be working between six inches to two feet away from the surface you're cleaning, so if you are cleaning the exterior of a multi-story house, you'll probably need a ladder. Remember, just because the water can reach the target, it doesn't mean it is cleaning effectively.
• Check your hoses and cords. You don't want to stop halfway through and reconnect to a different spigot, nor do you want to unplug and re-plug the machine into a different power outlet. Do a quick check that everything will reach everywhere you want to go, and that the power outlet you're using will never be in the path of the spray.

Test it!

You're almost ready to get started, but before you start spraying the wall right next to the front door, you should test your setup on an inconspicuous part of the house. If the pressure is too high or you have the wrong nozzle attached, you're much better off learning that while cleaning the corner of the house around back behind the bushes than on the part you can see from the street. Also, keep in mind that just because the whole house was painted at the same time with the same paint, different parts may be harder to clean than others.

Get it done

Pressure washing is a quick way to thoroughly wash your house, your deck, and even your patio furniture. And it's easy enough for almost anyone to do themselves as long as you prepare and use proper caution.

Do you have a power washing routine that you can share with newcomers? Any tips that we haven't mentioned here?

Jay Harris, a Home Depot sales associate in the Chicago area, is a regular Home Depot blog contributor on outdoor projects and products. Jay's interests range from riding lawn mowers [1] to chainsaws [2].