A pressure washer can become an invaluable tool for home maintenance. However, this does not mean you should purchase a pressure washer and proceed to spray everything in and around your home. It is a good idea to make sure you understand which surfaces a pressure washer is likely to damage before you remove your new tool from the box and put it to use.

Wood Siding

While you can use a pressure washer to clean wood siding, it is probably not one of the situations when using pressure washing is a good idea. If the pressure from the machine is too strong, water will make its way under the siding’s exterior surface. When this happens, insulation damage, mold growth, and the destruction of wiring are among the possible consequences.

Asphalt Shingles

It is best to keep your pressure washer away from your roof if you have asphalt shingles. A pressure washer may cause problems by stripping the protective granules from your roof. It is also an extreme safety risk to use a pressure washer in a high place.

Air Conditioners

Many horror stories exist that tell the stories of homeowners who thought it was a good idea to pressure wash their outside air conditioning units. A strong stream of water can crush the fins that are part of the casing for the system and cause problems with airflow. This damage can result in costly repairs and shorten the lifespan of your AC system.

Lead Paint

A pressure washer is not a safe tool for the removal of lead paint. A pressure washer will send paint chunks into the air surrounding your home. The paint chunks will then have the potential to become a health risk for you, a member of your family, or a neighbor. A better idea is to carefully remove, contain, and dispose of unwanted lead paint.

Living Creatures

This one may seem like a no-brainer, but accidents involving pressure washers and living things are not as uncommon as one may think. The nozzle of a pressure washer should never become aimed at a pet, plant, or another human being. Pets and animals may receive serious injuries, and a plant will face sure destruction.


You may be able to get away with pressure washing your car on a low setting, but it is probably not worth the risk. Pressure washers can damage cars through small dents and chips in the paint. This damage can cause further problems by making your car or truck more vulnerable to rust. If you do choose to wash the exterior of your car with a pressure washer, make sure:

  • Don’t park on gravel
  • Use a wide stream of water to protect fragile areas
  • Loosen grime with a brush attachment
  • Stand more than three feet away from the vehicle


You might become tempted to clean the inside of your gutters with your new pressure washer. However, it is a good idea to resist this temptation. You are better off using your hand or a stick to remove large debris. You can then rinse things off with a water source that uses less pressure.


Glass is often not able to withstand the force of a pressure washer. This fact has not stopped homeowners in the past from testing this theory, however. Broken windows are a steep price to pay for an attempt at avoiding the labor involved with washing the windows of your home by hand. The same holds for the windows of your car and other things made with glass.

The Bottom Line

A pressure washer is a useful tool that can save you time, energy, and money when used properly. But using a pressure washer on the wrong surface can result in disastrous consequences. Owners of pressure washers should understand that pressure washers are not the best option for all surfaces.

The last thing you want to do when you’re saving money by doing it yourself is end up costing even more money than it would have cost to hire a professional in the first place. On top of potentially saving your home, property, and bank account, a professional offers the following benefits:

  • It is safer to hire an experienced pro
  • The job will be done faster and with no effort on your part
  • Using a professional is better for the environment

If you have any doubts about whether or not it is safe to pressure-wash something, it’s best to err on the side of caution and let a professional handle it.