How To Pressure Wash A House

When researching for this post, we came up with many ways to pressure wash a house and a few that argue against using a pressure washer on your house at all. The truth is, as long as you take care, and are mindful of what you’re doing, pressure washing is the easiest way to clean a house. The thing to remember is that houses are usually made from more than one material.

 There’s bricks, wooden fascias, plastics, aluminium, concrete, well, you name it and there’s a good possibility that someone will have included it in the construction of a house somewhere. That means treating different surfaces in different ways but it doesn’t mean you can’t use a pressure washer. You just have to be armed with a bit more know-how that’s all.

The Correct Pressure For The Surface Being Pressure Washed

Most commercial pressure washers are too powerful, and that can damage your house, but domestic machines are less powerful, and you’ll be in control. And let’s face it, you don’t want to damage your own home. So let’s have a quick look at building materials and the maximum safe pressures for cleaning them without damage.

Building materialMaximum pressure
Aluminium500 PSi
Brick1000 PSi
Wooden fascias (softwood)600 PSi
Wooden fascias (hardwood)1500 PSi
Plastic (vinyl)  fascias1600 PSi
Concrete3000 PSi

We would just add here that in the interests of safety it is not advisable to wash windows with a pressure washer. Not only can the high-pressure break the glass, but it can also loosen and even remove putty resulting in the glass falling out.

Which Nozzle Should You Use For Pressure Washing A House?

pressure washing

Now let’s look at nozzles, pressure washer nozzles come in 5 colours each one with a different spray pattern for a different task. There is also a turbo nozzle which is like a cross between the red and green nozzles plus it spins as it sprays. We always recommend the lowest powered nozzle for any particular job for safety purposes.

Material To be washedRecommended nozzle colour
Wooden fascias (softwood)Green (with care)
Wooden fascias (hardwood)Green (with care)
Plastic fascias (vinyl)Green

Pressure Washing A House – Safety Tips

There are many hazards and pitfalls when doing any DIY around the home, and using a pressure washer causes more than usual. Always remember to:

  • Use the lowest water pressure
    Too much pressure can and will damage your house, always use the lower option when it comes to using pressure washers. We’ve given you the maximum PSi to use but start lower and only work up if necessary.
  • Use the correct nozzle for the surface being washed
    Always be aware that there are many different surfaces on the same building and they need to be treated differently. Don’t get carried away and think one size fits all because it definitely will not end well.
  • Before pressure washing be sure the surface is sound
    If there are any signs of loose or missing mortar, make good and allow to dry for 7 days before using a pressure washer on the repair. Be sure wood is not damaged or flaking.

Personal Safety Tips

It’s not just the building that can get damaged, there are many accidents recorded through the misuse or improper use of pressure washers. You must take responsibility for your own safety. Always:

  • Wear PPE
    Goggles, gloves, boots or closed-toe shoes, long-sleeved shirts and long trousers should always be worn when operating a high-powered pressure washer.
  • Be aware of, and remove all obstacles
    Anything that might cause you to trip including pot plants, garden furniture, tools, toys, pipes, cables etc.Should be moved away from the area you are planning to clean.
  • Protect electrical equipment
    Cover any outdoor sockets, junction boxes, meters, outdoor lighting, alarm systems etc with plastic sheeting secured with masking tape.
  • Cover plants
    Any plants growing close to the area being cleaned should be covered with plastic sheeting or old cloths, to protect them from any flying debris, water damage or detergents.
  • Keep children safe
    It’s only natural that children will want to be wherever dad is, even more so when there’s something going on. Always remember that young children and pressure washers don’t mix. The pressurised water ejected from a pressure washer can do serious damage, and cause some really gruesome injuries, always be aware of what the kids are up to and never spray them with the pressure washer.
  • Look out for pets
    Just like the kids, pets like to be where the action is too. Pressure washers can seriously lacerate skin and inflict really appalling injuries. Be aware of your pets and never spray them with pressurised water from a pressure washer.
  • Never use a ladder
    Using a ladder whilst operating a pressure washer is an accident waiting to happen. Depending on what type of material you’re cleaning, you could have the force of 3000 PSi leaving your pressure washer. That can be difficult to hold and control with both feet firmly planted on the ground.
    But you won’t be on the ground, you’ll be perched somewhat precariously, halfway up a ladder. Imagine trying to hold onto the ladder for support while aiming and operating a water jet at 3000 PSi. The lads at the local A&E department will have a story to tell their grandkids.

The Safe Way To Pressure Wash A House

By following all of our advice so far, you should remain safe, and your home should remain intact from the whole pressure washing experience. Now let’s look at the correct technique for using a pressure washer. Whether it’s a concrete wall, a brick wall, aluminium sidings, plastic (vinyl) sidings, wooden fascias or any other material, the technique for using a pressure washer to clean it is very similar.

We’ve compiled an easy to follow step by step guide to make pressure washing your house a safe and simple task. Just follow these instructions and your house will be clean in no time.

How To Pressure Wash A House Safely In 9 Easy Steps

You need to be aware of maximum safe pressures (PSi) and nozzle colour for the various surfaces you intend to clean. It’s not a case of “one size fits all”, you can’t blast every surface with the same power and nozzle. Treat areas as separate sections and set the pressure washer up accordingly, when finished move on to the next section.

  1. Connect the garden hose
    The garden hose should connect to the inlet valve on the pressure washer and the other end of the hose connects to the outdoor tap. Turn the outdoor tap on fully.
  2. Pull the trigger
    Without turning the pressure water on, pull the trigger and allow the water to flow for around 30 seconds. This is to ensure there’s no air in the system.
  3. Turn the pressure washer on
    Using the on/off switch on the pressure washer, turn the power on. 
  4. Soak the wall
    Using the white nozzle completely soak the wall, starting from the bottom of the wall work upwards to ensure the whole wall  gets covered in water.
  5. Apply the detergent
    Ensuring you’re using the correct detergent for the surface you’re washing, and the correct type of detergent for your pressure washer, apply the detergent to the wall from the bottom up, using the black detergent nozzle.
  6. Leave to soak
    Allowing the correct time for your product (usually 10 to 15 minutes) let the detergent soak into the dirt and grime on the wall.
  7. Use a brush attachment to remove stuck on stains
    Any really stubborn stains that are proving difficult to remove can be scrubbed using a brush attachment on your pressure washer. The brush works at low pressure so it won’t damage your surface but will remove the stains.
  8. Rinse the surface
    Change to the white nozzle after the correct amount of soaking in time has elapsed. Rinse the wall from top to bottom, remember to never concentrate on any particular area for too long to avoid damaging the wall. Move the water in a circular motion starting at the very top and working down to the bottom. Move slowly over each section, but keep moving.
  9. Allow to dry out
    Once the surface has completely dried out, use a sealer to protect the wall if appropriate for the material type.

For an easy to follow guide on how to pressure wash a roof follow this link.

Frequently Asked Questions

Is Power Washing bad for your house?

Power washing is not bad for your house, as long as it is done correctly. Always use the minimum pressure and the correct nozzle.

Can you use bleach to pressure wash a house?

You can use bleach to pressure wash a house but you run the risk of damaging your pressure washer and voiding your warranty.

How often should a house be power washed?

A house should be power washed as often as is necessary, because if your house is on a main road it will get dirty quicker and need to be washed at a more regular interval. The average house needs power washing once a year.

How long should it take to power wash a house?

It should take between 30 minutes to 3 hours to power wash a house, depending on how dirty it is, and how easily accessible it is.

What time of year is best to power wash a house?

The best time of year to power wash a house is between Spring and early Autumn (fall) This will avoid any extremes in temperatures.

How many gallons of water does it take to clean a house?

How many gallons of water it takes to clean a house with a pressure washer depends on how many gallons per minute (GPM) the pressure washer uses and how long it takes to clean the house. For example 30 minutes cleaning time with a GPM of 8 gallons will use 240 gallons of water.

Is it bad to power wash vinyl siding?

It is not bad to power wash vinyl siding as long as you are careful and use the correct PSi and nozzle.

Can pressure washing damage windows?

Pressure washing can damage windows, the glass can shatter and the high water pressure can remove the putty that’s holding the glass in place.

Should you wear a mask while pressure washing?

You should wear a mask while pressure washing to prevent any accidents caused by flying debris.

What happens if you spray yourself with a pressure washer?

What happens if you spray yourself with a pressure washer is you get hurt. High-pressure water from a pressure washer can cause serious skin injuries.

Are power washer tips Universal?

Power washer tips are not universal, even though they mostly all use the same colour coded system, each company makes nozzles to fit their machines.

What PSI can cut skin?

1,160 PSi can cut skin, 2,900 PSi can cut through flesh, that’s why you should never point the pressure washer at anyone.

Can you lower the psi on a pressure washer?

You can lower the PSi on a pressure washer simply by stepping back. Some machines have a regulator on the pump to increase or decrease the pressure. But standing further away from the object being washed lowers the PSi.

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