There are a number of reasons why a pressure washer/jet washer surface cleaner leaves stripes when cleaning a hard surface. This could be due to one or more of the following: nozzles are worn, nozzles are not aligned with the bar, and technique. We will address these in this article, which will ensure you will never leave stripes on a hard surface again.

 Lines on a AstroTurf surface after cleaning by a surface cleaner

A surface cleaner is often referred to as a ‘whirlaway’ in the pressure washing community. It is an attachment which attaches to your high pressure hose, and cleans the surface through usually 2 or more rotating jets. With the aim of cleaning the surface evenly and without streaks or stripes. Broadly speaking the nozzles project the water at a rate registered by the jet washing pump divided by the amount of jets and the nozzle ratings. The jets spin to produce an even cleaning path. Therefore, there should be stripes when using the surface cleaner.

 Large metal pressure washer surface cleaner (whirlaway)

Nozzles are worn

 Equipment maintenance is paramount in ensuring an issue free job, always check the equipment before starting a job. Having clean and unworn nozzles is crucial for the proper functioning of a jet washing surface cleaner. Overtime and use, the nozzles become worn. The high pressure starts to wear down the size of the jets, this may be uneven across the 2 or more jets on the surface cleaner. What’s more, dirt can ingress into the tight jet holes. Both aforementioned scenarios, can create uneven pressure. Therefore, the cleaning performance is significantly effected. In turn, may result in stripes when cleaning a hard surface using a surface cleaner.  The nozzles are responsible for creating the pressure needed to clean the surface effectively. If they become worn or clogged, the pressure can decrease, leading to a less thorough cleaning job.

Additionally, worn nozzles can cause damage to the surface being cleaned. As they may create uneven pressure or even gouge the surface. Therefore, it is important to regularly inspect and replace any worn or damaged nozzles. This ensures the best possible cleaning results and prevent any potential damage to the surface being cleaned. By maintaining clean and functional nozzles, you can improve the efficiency and effectiveness of your jet washing surface cleaner.

Nozzles are not Aligned

The nozzles or jets, on the whirlaway have to be aligned with the arm of the bar otherwise the bar will not spin. The surface cleaner arm, found under the hood is set at an angle, Which allows the jets to propel the arm in a circular motion. Although, if the jets slit is not aligned with the arm of the jet, this results in the arm not spinning adequately or spinning at all. It is easy to not implement this, especially if you are a beginner, as it is not always clear that this is necessary for the functioning of the surface cleaner. But it is essential to the sufficient function of the surface cleaner. As discussed in the last section, proper functioning of the surface cleaner is essential to a successful hard surface clean. As if the surface cleaner is not spinning adequately this could also be the cause of stripes when cleaning using a surface cleaner.

 Underside of a flat surface cleaner, showing the arm and nozzles under the skirt.

Use a ‘figure of 8’ Technique

Technique when using a surface cleaner is essential, as without proper technique this could result in an uneven clean leaving stripes. Use a ‘figure-of-8’ technique to ensure the surface is cleaned evenly, and one area or section doesn’t get more attention than others. The technique also ensure a better ‘blend’ of the cleaning area. With correct technique there would be no stripes; consider the surface when planning the clean.


We have found 3 possible reasons why the surface cleaner is leaving stripes when jet washing, worn nozzles, misaligned nozzles, and technique. We can break it down into equipment maintenance and technique. Therefore, when preparing for a job ensure that all equipment is in good shape by checking the condition and fitting of the jets, and the rest of the equipment for that matter. Also, when on the job, ensure you are using the correct technique for the equipment and type of surface. This will significantly reduce the chances of leaving stripes when using a surface cleaner again. If you are still facing this issue, please get in touch and we will be happy to advice further.