Pressure washers are powerful machines that are helping to clean the exterior of your house efficiently. They use high-pressure water to blast dirt away. But in some circumstances, this does more harm than good. Using high pressure on concrete driveways, bricks, and other hard surfaces will be fine. For some softer surfaces, you have to use lower pressure. But there are also some materials where you should not use high-pressure water. Materials that can be damaged should be handled carefully and better cleaned differently.
What should you not pressure wash:
In general, you should not pressure wash materials that are painted. Also, asphalt roofing, Electrical boxes, outdoor lighting, your AC outdoor unit, old motar, grout and windows. Also, take care of the pressure when cleaning your car and engine, bikes, old plastic, and other soft material.
By the end of this article, you will learn specific precautions to follow while using a pressure washer. We will also provide you with the reasoning about why you should not use pressure washers inside your home and which surfaces you should never pressure wash.
Contents
- 1 What should you not pressure wash, 21 examples
- 2 What should you not do with a pressure washer?
- 2.1 ● Do not use high-pressure water for some materials
- 2.2 ● Do not use water only
- 2.3 ● Do not use the same nozzle for every surface
- 2.4 ● Do not use the same spray’s angle for every surface
- 2.5 ● Do not pressure wash every surface
- 2.6 ● Do not use hot water for some materials
- 2.7 ● Do not pressure wash air conditioners
- 2.8 ● Do not pressure wash plants
- 3 Why should you not pressure wash your house?
- 4 Can you power wash inside your house?
- 5 Should you wear a mask while pressure washing?
What should you not pressure wash, 21 examples
The following table shows 21 examples of materials that you should not pressure wash:
Material | Why should you not pressure wash it? |
|---|---|
All painted material | The high water pressure will remove, or weaker the paint on most materials |
Stained wood | You will remove the stain from the wood |
Lead Paint | The lead paint will get into the air |
Asphalt roofing | You will remove the granules from the asphalt roof or damage the shingles |
Old wood | Old wood can be weaker |
Old plastic | Be careful with old plastic. Some can be weakened by the UV rays from the sun and can be damaged easily |
Electrical boxes, equipment, and Panels | The water can force itself in the box or panel and create a short circuit |
Outdoor lighting | The water can find its way to the internals of the light |
Air Conditioner | The pressure can damage the internals of the outer unit |
Old Mortar | Old mortar can be weakened over time and can easily damage |
Grout between tiles | The pressure can wash away the grout. Most grout is also not waterproof |
People and Animals | It does not need an explanation |
Plants and trees | You will wash away most plants and damage trees |
Windows | The pressure can crack the window |
Cars | High-pressure water can damage the paint |
Engine | Water can find its way in specific components like for example, the fuse box |
Bike | The water can enter some more delicate areas like the crankcase or wheel bearings |
Gutters | The high pressure from a different angle can damage the gutter |
Vinyl Siding | The siding can be damaged easily |
Most garden tiles | Be careful not to remove all the sand between the garden tiles |
What should you not do with a pressure washer?
While pressure washing any surface, ensure that you are not using it at a higher pressure than what is recommended. You should use detergents along with pressure washers to get rid of older and tougher stains. Use the correct nozzle for the job. Different nozzle types have different spraying patterns. And different surface types require different spraying patterns to avoid damage. It would be best if you do not use your pressure washer on air conditioners, old mortar, and plants.
● Do not use high-pressure water for some materials
The pressure washer uses high-pressure water to clean different surfaces easily. This pressure is significantly higher than normal water from the tap. You must adjust the pressure of water according to the strength of the surface you are cleaning. If not, you could end up damaging surfaces like vinyl sidings, wood, or your car.
● Do not use water only
Pressure washers are well suited to clean surfaces with tough stains that cannot be removed using a normal hose. To clean some stains, it helps to use a detergent before pressure washing it. This will break up the dirt and kill mold. After applying the detergent on the surface, wait for at least 5 to 10 minutes and then clean it using your pressure washer.
● Do not use the same nozzle for every surface
Every surface requires a different spray pattern of water for effective cleaning. There are a variety of nozzles that can be used at the tip of the pressure washer. They can produce spray patterns ranging from wide to narrow streams. The basic rule is that: the more narrow the nozzle, the higher pressure of water. To wash surfaces like sidings, use a wide 40-degree nozzle. A narrow 25-degree or even 0-degree nozzle works best to clean the dirt from concrete surfaces and remove older and tougher stains.
● Do not use the same spray’s angle for every surface
For an effective cleaning with the pressure washer, you must adjust the angle of the water spray according to the surface you are washing. Use 90 degrees for tough stains. But cleaning the underside of the patio table or siding is better using a lower angle.
● Do not pressure wash every surface
Although the water pressure can be changed for most pressure washers, some areas and surfaces should not be washed. Even with the lowest PSI setting. Some areas in the house already show the sign of wear and tear, and pressure washing these surfaces can easily cause damage.
● Do not use hot water for some materials
Power washers are pressure washers that use hot water. The hot water helps to clean the surface faster. But be careful with some materials, as hot water can easily damage them.
● Do not pressure wash air conditioners
At the start of every summer season, most people think it is good to clean their air conditioner. But do not use a pressure washer for this. The water can damage the fins of the machine. It is better to use a vacuum and hose to clean the outside and inside your air conditioner outdoor unit.
● Do not pressure wash plants
The pressure from a pressure washer is much higher than that from a hose. Never use it to water or clean your plants as it will most certainly destroy them.
Why should you not pressure wash your house?
The high-pressure water can seep through small cracks in the wall to the inside of the wall. This can result in unwanted moisture and humidity. Also, using the pressure washer at high PSI settings can result in cracks and holes in the wood. And it can damage old mortar or loose paint on the surface.
Many people pressure wash their house, but only a few people know what damage it can do. To paint your house, cleaning the paint is the first step. But if you want to use your pressure washer for this, it should be done correctly. With the correct pressure, nozzle, and angle. If not, it can cause damage to the inside of your house’s walls and other areas.
● Reason 1 not to use a pressure washer to clean your house: Water inside the walls
The pressure washer shoots water out of its nozzle at high pressure that can reach 3000 psi. This high pressure can be destructive. It can blast through solid wood and some other materials if you do not use the correct pressure. Also, use the correct nozzle, and maintain a proper distance between the nozzle of the pressure washer and the surface.
If you have areas in your house with wood sidings and shingles, there is a high chance that pressure washing will blast the water inside the wall cavities and plaster. These surfaces always are full of joints and cracks. The pressure helps the water find a way through these. And once inside, it is challenging for it to evaporate.
● Reason 2 not to use a pressure washer to clean your house: Loose mortar
If you have a brick house, or part of it uses bricks, you must be thinking that it is ok to use a pressure washer to clean it. Generally, using a pressure washer to clean bricks is fine. But, if there is any loose mortar on the surface, you will easily wash it away. Or you will weaken it and end up damaging it instead of cleaning it. Start cleaning with low pressure, and only increase it when needed.
● Reason 3 not to use a pressure washer to clean your house: Wood damage
Some painters use a pressure washer to clean wood and remove the paint. They use a high pressure only on the hardwood. Softer wood can easily damage. Using high pressure can lead to holes and cracks in the wood.
From the above discussion, we can say that you have to take care when using a pressure washer to clean your house. For some surfaces, it is ok. For others, it is not. It is important to check before starting to keep the surface you want to clean free from any damage.
Can you power wash inside your house?
In general, I do not recommend using a pressure washer inside your house. Although you can adjust the pressure of your pressure washer, it is still high enough to damage most items and materials. Part of the spray will bounce back and add a lot of extra moisture. Glass inside your house can easily crack. In some circumstances, you can use the pressure washer to clean the bathroom floors, bathtubs, and showers. But even in those areas that are built to deal with water, the high pressure can do a lot of harm. Joints and seals are not built for such pressures. They will be ok for regular moisture and water but can be less effective against high pressure.
Should you wear a mask while pressure washing?
In general, you should wear a face mask while pressure washing. The water itself is usually not a problem, but the high pressure can send dirt or other particles flying around. Those can be more harmful to your eyes. Also when you use detergents to get rid of tougher stains, they can be harmful.
Can you power wash inside your house?
No, it is not recommended to power wash inside your house due to the high pressure that can cause damage to surfaces and add extra moisture. Use caution in specific areas if necessary.
Can pressure washing damage old plastic materials?
Hi Dustin, yes, pressure washing can damage old plastic materials. It’s best to handle them carefully or clean them differently. Remember to adjust the pressure based on the surface you’re cleaning.
How do you adjust the pressure for different surfaces?
Adjust the pressure based on the surface material being cleaned. Use lower pressure for softer surfaces like wood, painted materials, and plants. Be cautious to prevent damage.
How can you protect wood surfaces when pressure washing?
Thank you for your question, Logan. Materials like painted surfaces, stained wood, lead paint, and more should not be pressure washed to avoid damage. Specific precautions are crucial when using a pressure washer.
Should you pressure wash your outdoor lighting fixtures?
Hi Julian, I recommend not pressure washing outdoor lighting fixtures to avoid damaging the internals of the light. It’s best to clean them differently. Hope this helps!
What are the risks of pressure washing cars and bikes?
Pressure washing cars and bikes can damage the paint and delicate components. Avoid using high pressure on these surfaces. Be cautious with materials that can be easily harmed by water.
What type of nozzle should be used for different surfaces?
For different surfaces, use lower pressure for soft materials and be cautious with painted, old, and delicate surfaces. Always adjust pressure, use detergents, and choose the correct nozzle. Hope this helps!
What about using a pressure washer on outdoor furniture and cushions? How should those be cleaned without risking damage?
It is not recommended to use a pressure washer on outdoor furniture and cushions, as the high pressure can damage the materials. It is better to clean them using a gentle soap and water solution.
What precautions should be taken when pressure washing air conditioners?
Thank you for your question, Alfredo! When pressure washing air conditioners, avoid using high pressure to prevent damage to the fins and internals of the unit. Be cautious with delicate materials!
Why should you not pressure wash materials like painted surfaces and roofs?
Thank you for your insightful question, Kathryn! Materials like painted surfaces and roofs can be damaged by high-pressure water from pressure washers. It’s essential to handle them with care and choose a different cleaning method.
Should you clean air conditioners with a pressure washer?
Using a pressure washer on your air conditioner can damage the internals. Be cautious and avoid using high-pressure water on delicate materials. Take care when cleaning different surfaces.
Are there specific surfaces that should not be pressure washed?
Thank you for your question, Bradley. Materials like painted surfaces, asphalt roofing, electrical boxes, and old mortar should not be pressure washed to prevent damage. Be cautious with softer materials and follow specific precautions.
What should you be cautious of when using a pressure washer to clean painted surfaces?
Thank you for your question, Kathryn. When using a pressure washer on painted surfaces, be cautious of removing or weakening the paint. It’s best to use lower pressure and avoid high-pressure water on painted materials.
Should you wear a mask while pressure washing?
Thank you for your question, Daryl. It’s best to wear a mask while pressure washing to protect yourself from flying dirt and particles. Stay safe!
Can pressure washing damage plants and trees?
Hi Colleen, yes, pressure washing can damage plants and trees. Be cautious when cleaning around them to avoid harm. Check out the blog post for more details on what materials to avoid pressure washing.
Should you be concerned about water getting inside walls when pressure washing a house?
It’s best to avoid pressure washing inside walls as the water can cause unwanted moisture. Also, be cautious when cleaning painted materials, asphalt roofing, and plants. Stay safe!
Is using a pressure washer safe for old mortar and grout?
It is not safe to use a pressure washer on old mortar and grout as it can damage them. Always use caution with softer materials.
Is hot water safe to use for all materials with a pressure washer?
Using hot water with a pressure washer is not safe for all materials. Avoid using it on painted surfaces, asphalt roofing, electrical boxes, old mortar, grout, and more. Make sure to adjust the pressure and follow precautions.
What about using a pressure washer on outdoor furniture and cushions? How should those be cleaned without risking damage?
Hi Esther, it’s best to avoid pressure washing outdoor furniture and cushions to prevent damage. Use a gentle cleaner and a soft brush instead for a safer clean.
Should you use detergents with a pressure washer?
Hi Lucille, thank you for your comment! It’s important to use caution with pressure washers. Avoid using them on painted surfaces, asphalt roofing, electrical boxes, AC units, and more. Stay safe!
Is it safe to pressure wash windows?
It is not safe to pressure wash windows. The high-pressure water can crack the window panes. Stick to traditional window cleaning methods to avoid damage.