Lowes created a great chart showing the recommended pressure washer pressures for various cleaning jobs.

Here it is:

Pressure Washer Pressures Chart

Chart was found on the Lowes website here.

What is the Best Pressure Washer Then?

You can see that for around the house you can’t go wrong with a heavy-duty or medium-duty. If you want to wash your car with a heavy-duty just be sure to hold the pressure a little further away. For every doubling of distance you move away you half the effective pressure.

Possible Damage

Here’s a picture of what happens if you hold high pressure too close to your wood deck:

Pressure washing damage

Image source: http://clarkcountypaintinginc.com/pressure-washing/