This quick guide will outline what jet sizes you should use for your flat surface cleaner (SFC) or whirlaway. The SFC is a brilliant tool for cleaning large areas of patio or driveway, with 2 fast spinning jets with skirting to control the dirt it allows for quick cleaning whilst also helps manage the mess. Although, depending on the surface you are cleaning you may choose to change your jet size.

Angle sizes on Jets

There are several size jets to choose from on your whirlaway from 0 to 60 degrees. Typically, 15 or 25 degrees are the standard. Although, for block paving a size 15 jet is chosen for Surrey Jet Washing, when cleaning block paving. 15 degrees are chosen for block paving as they provide a quicker deeper cleaning, and because they are hard wearing it will not damage them.

When cleaning concrete slabs 25-degree jets are chosen, this is because they apply less pressure reducing the risk of damage. Whilst still providing a thorough clean.

choosing the right jet

When cleaning tarmac or decking a size 40 jet is advised, this is because high pressure can damage these surfaces. Therefore, a size 40 jet is chosen because of the wide angle it reduces the pressure point on the hard surface. As always, test on a safe test patch before continuing with the rest of the surface. Consult Surrey Jet Washing if you have further question or seeking free advice, we are always happy to help.


To conclude, the size jets you choose to use in your FSC or whirlaway depends on the surface. Typically, it is between 15 degree and 40 degrees. 0-degree pencil jets and size 60 chemical jets are not suitable 99.9% of the time.