Looking for some advice. I started my power washing business last year. Ive been doing mostly house cleaning and having pretty good results. I was contacted to give a price on cleaning a local tennis court (actually its four courts side by side). I went and paced it off, roughly 21300 sq feet of area. Pretty dirty with some surface damage in one corner. Most of the surface looks in great shape, just dirty. The owner has realistic expectations regarding results.
I have a 3000psi/5 gpm hot water machine. I also have a 20 inch surface cleaner thats currently washing at around 1800 psi with the included nozzles. I only have the ability to DS at the current time so Im limited on my concentration of SH.
So my thought is…If I get the job, I’ll order an M Jet and wash with 2-3% SH and either Simply Green or Elemonator. I’ll use primarily the surface cleaner, using less pressure and caution on the damage areas. I’ll wash 1/4 of each court at a time, trying to keep everything wet and the area manageable. As far as price, I was thinking .07 -.10 cents per square foot.
Any advice? Am I crazy or does my thinking sound like a reasonable plan? Thanks in advance!
I used a surface cleaner once and ruined a court. Others seem to have no problems. We blow them very very well with a blower, xjet straight 12.5% then rinse a lot. One side at a time. I hate them with a passion but every apartment complex seems to have one.
My plan was to do a test area first. I certainly can order a couple more nozzles to lower the pressure of the surface cleaner just to be safe. I wonder what would be a good size? Straight 12.5%? Wow, I wasn’t thinking I would need that strong. I can always start low and work my way up. I was also planing on using hot water, around 150 degrees. Thanks for the advice!
Ours are asphalt with green thermoplastic paint. Mostly covered with mildew and black. Yours might be something else. I wouldn’t use hot water. You aren’t removing grease and it might break down the paint.
Less pressure, more SH and no heat. Thanks. I know the surface is asphalt but not sure what kind of paint they used or how old. I have several questions when I meet him on Monday. I also need to check runoff and water supply.
As far as my surface cleaner…my gauge shows 1800 psi at the trigger. It has two nozzles, does that make it 900 psi at each? or 1800 at each?
I’ll try to post a couple pictures tomorrow. This would be a great job to get, both in exposure and future work. Thanks again for the advice.
Couldn’t be 1800 at each if your machine is at 3000 psi. I’m curious for someone who knows the machine/technical stuff better to answer this though, because 900 psi anywhere from a 3000 psi machine doesn’t feel right in my dinosaur brain.
Ok, first, are you sure you’re only getting 1800 at the trigger? Do you have a pressure gage? Check it coming out of the pump first. Then check it at nozzle. There’s no way in hell you should be losing 1200 psi, even running thru heater coil. On a 5 you should only be losing about 130psi per 100ft of hose. Can lose some psi going thru heater. May want to put a valve so you can bypass heater if not using heat.
What ever you have at the trigger is split between nozzles as far as volume goes. So that means you’ve only got like 1800 or less psi on your surface cleaner depending on nozzles. Look at see what size nozzles you have.
While you’re at it, check your flow. Just stick end of hose or whip line in a bucket for 1min.
Match GPM numbers to the nozzle and you get max PSI advertised for your pump, right? Isn’t there a nozzle chart somewhere for reducing PSI at the nozzle?
I have a pressure gauge, but I’ve actually never used it. Don’t know what I’m looking for. Ha!
I recently just finished cleaning 52,000 Sq ft of tennis courts.
The number one thing to do is “set expectations”.
The courts I did were covered in dense black mold, so surface cleaning was a must. But you need to 100% fine tune the pressure and dial in the proper soap for pre washing.
Pick a far corner and complete a test area large enough to see the results when dry.
Using a surface cleaner will def leave somewhat visible lines, but if your set up right it’s fine in the end.
Over time the lines start to fade.
Just make sure you advise them of this before starting. Setting expectations is key in this industry.
Here is a pic of half a court washed. My camera is screwed up so disregard the black spots you see.
Looks great. What chemicals did you use to clean with? What concentration worked best? This court is covered with black mold. I’ll try to post a couple pictures this afternoon.
As far as pressure…It’s my understanding that pressure at the gun will change based on the tip being used. My 5.5 tip produces 2600 psi at the gun, my 9.0 produces 1200 psi. Unless I’m wrong, showing 1800 psi when using the surface cleaner, means that my nozzle is not optimum for my unit (if you want higher pressure). The surface cleaner has GP 2504 nozzles X 2. I’m wondering if that might be a good thing for this tennis court. Lower pressure should be safer on the surface, as long as it has enough pressure to clean. I’m still thinking that the pressure is divided by the number of nozzles. In my case 900 psi X 2. Am I correct? Thoughts?
Already answered this above. You control pressure of surface cleaner with tips just like you do with any other nozzle. You’re splitting your flow, not your pressure.
See chart above- You have a 5gpm machine - if you have a 2 nozzle spray bar then you want max flow always, so 5 /2 nozzles you want 2.5gpm per nozzle (left column). Then to determine your pressure just look to the right, find pressure you want, look down and it will tell you what nozzle you need to achieve that pressure. So in your case, if you have 2504 nozzles then you’re getting 1500 psi out of each nozzle.
That’s pretty low. Even for residential concrete, you want between 2000-2500. But may work find for the tennis courts, just try a small area out of the way.
Thanks Racer for the information. I knew something must be divided by 2. I missed that in your earlier post. Here are a couple pictures. It looks better wet today than it did dry.
