In some cases when there is moss deeply imbedded in the joints of brick pavers, using the faster method of the hard surface cleaner won’t get all of the moss out. This is a situation where the surface being cleaned can withstand the pressure of the Turbo Nozzle. This video shows how quickly and effectively this attachment removes moss from the patio. Just know that not all surfaces can withstand the use of this nozzle. It can’t be used indiscriminately. A person has to know what surfaces are appropriate for having this nozzle used.
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These lines seen in the photos will appear many months after the work. These photos were taken about 8 months after this company did the pressure washing. It is clear that the person doing the work used a hard surface cleaner attachment and pushed the surface cleaner in straight lines. I’m quite sure that when this person finished the work, the surface looked fine. Because of the design of this piece of equipment, the right and left side of the cleaning area are hit by the water coming out of the tips on the rotary arm hundreds of times per foot whereas the center of the cleaning area is only hit a few times as the surface cleaner is pushed forward. This is why you see cleaner lines on the sides with a dirty area in the middle.
Because the right and left edges of the cleaning area get hit by the high pressure water hundreds of times per linear foot, these areas get cleaner than in the center. When the surface is not that dirty, it doesn’t make a huge difference. It will look uniform. When the surface is really green or black with mildew stains, the surface cleaner removes more of the staining along the edges than in the center. Upon completion of the work, it may not be noticeable but deep in the concrete remains some growth that you cannot see. When fall and winter comes around, the growth that remained in the center of the cleaning area will grow back very quickly whereas the sides of the cleaning area, having been hit hundreds by the spinning of the rotary arm, had all of the growth in the concrete removed which is why you see clean lines along the sides of the cleaning area.
To prevent this in a situation like this where the concrete has been neglected for many years, first spraying the surface with an appropriate cleaner would have prevented the manifestation of these lines many months later.
These surface cleaning attachments were designed for parkades and large parking lots where lines like this don’t manifest when done indoors like a parkade or aren’t bothersome on a large asphalt parking lot. Used in a residential setting, a different technique must be used to prevent a disastrous outcome as seen in the photos.
Cleaning flat surfaces with a surface cleaner is much faster and therefore less expensive. Adding the cost of applying a cleaner and the cost of the cleaner itself will increase the cost of the estimate provided to you. I’m guessing that often, companies don’t offer this because they either don’t know what the surface is going to look like in 8 months or they may not want to lose the job with a higher estimated cost.
We know the proper technique needed to prevent these lines and which cleaners should be applied (if needed) so that these lines don’t show up on you patios or walkways in the fall and winter.
