Hello, I’m Alexander and I’m excited to get started in this community!! I did a driveway pressure wash the other day and it was a very dirty driveway. I put a 1.5% SH mixture on the driveway. Let it sit for 10 minutes. Then pressure washed it with a wand and surface cleaner. My machine is 4000 PSI and 3.5 GPM which I understand isn’t very powerful but I went very slowly and I did multiple passes but the driveway just wouldn’t get cleaner then this. Any suggestions would be greatly appreciated 
Do you have any before shots? Did you let the SH dry during that 10 minutes? Is this photo from when it was still wet/damp? Looks like that concrete is just old and has wear and discoloration to it. Only thing I would add is that on really dirty driveways you may need to post-treat closer to 3%.
Hey thanks for responding! I did let the concrete sit for 10 mins and this is the before picture:
I would like to get a higher dilution but I’m not sure how to do that because my down stream injector with a check valve only does about 1.5-1.7.
And also, I did let the SH dry while doing nothing to it for 10 mins and the after picture is from when it was still not fully dry. A little damp.
Cheapest way would be to use a pump up sprayer, but on large drives that sucks… x-jet or batch mix/proportioner would be the more costly but efficient ways to get a hotter mix.
Don’t let it dry unless you’re post treating. The hotter a mix you hit it the less dwell time it needs.
Based on the before it looks like that concrete is just weathered/aged… also since it was still wet it will look different once fully dry. Go back and take a look, and if need be clean it again.
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I gotcha, that’s so helpful thanks so much! I’ll definitely look into the pump up sprayer because my budget isn’t super high atm
A 2-gal pump up sprayer that can safely handle bleach/harsh chemicals would be the cheapest way. Another option would be to use a 12v sprayer that would also be rated for bleach/harsh chemicals. There’s plenty of options online, but Northern Tool or Ace would sell them. My latest 12v came from Tractor Supply and it’s being going strong since last fall. You can also oftentimes find a used ATV sprayer and that would work as well; it’ll have the tank, pump, hose and gun on it already.
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what tips are in your surface cleaner? Did you check them on the nozzle chart?
Something’s not right here. That driveway doesn’t look touched at all. Either we are getting our leg pulled or that’s the worst case of magnesium I’ve ever seen…well, 6 years worth anyway.
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I’m not sure. What is the nozzle chart? I am new to pressure washing driveways as you can probably tell. I am familiar with the nozzle chart for the wand nozzles but do surface cleaners have a chart as well?
That’s what I’m saying! I took a lot of dirt off as well. I’ll attach a picture of all the dirt I was taking off and it still came out looking awful. I’m very confused.
Yeah I’m thinking the pump sprayer will be the move for me. Thanks for the advice!
Nozzle chart applies to surface cleaners you just divide by however many nozzles you have. I don’t think that surface cleaner has removable nozzles however.
doubt you can do anything to that drive except seal w/color acrylic sealer like eagle sealer
looks like it’s been torn up over years and probably sealed without cleaning
Get you a pump up and go back out there and spray a little section with straight SH, let dry and send us a pic.
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“SH” you mean hypochlorite de soduim ?
Sodium Hypochlorite
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