What's the best concrete prewash mix?

I’ve experimented with different mixes and I’ve found that downstreaming bleach with some elemonator and dawn(more suds) works the best. I haven’t killed any plants or had any negative experiences yet. Is this what everyone else does? Everyone talks about detergents and such but I rarely hear what those detergents are or in what mixtures. Could some of you pros fill me in?

G’day Zach, I find that while ds’ing is great for houses, but it is just not strong enough for concrete or pavers (my house wash mix puts the SodiumHypoChlorite on at about 1%) so I X-jet (sometimes with the throttle/rpm reduced, or with my low volume pump, to it make it even stronger). Check out the ratio chart http://www.xteriorsales.com/index.php/xjet/49.html to see what’s possible.


I Just use 50/50 SH and water in a 5 gallon bucket and DS it on with some dawn or other soap, Works well for me

All the best
Troy Hillard
Wash Rite House Wash

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Thanks guys for your response! It’s so cool to have an online source like this:) I have read a lot about the x jet but haven’t got one yet. I did notice that downstreaming dilutes it a ton. The x jet dilutes it less?

Yes, check out the ratio chart I linked to. There are a huge variety of ds’ers, so check what the manufacturer says about the ratio and then test it yourself.

Holy moly that’s awesome! That’s way more than downstreaming. I’ll have to buy one of those. Today I powerwashed a driveway that was covered in what looked like black mold. I down streamed bleach on it and it didn’t get rid of it.

Get one Zach, then read the GPM ratio chart, then test it.

I usually x-jet with my 7gpm, but if the concrete is extra filthy I’ll drop the revs to drop the volume and increase the ratio. When it’s extra extra filthy I use my 3gpm pump which draws at (theoretically) 1.2 : 1 (that’s 1 gallon of cleaning solution for every 1.2 gallons of water).

It hurts to think of all the time I’ve wasted d/s’ing house wash mix or using a pump-up sprayer to pre-treat concrete, and then the extra time with the surface cleaner…

Sure it’s a few dollars up front but it will give you much better results in less time - so a win for everyone.



Just ordered one! Thanks a ton:) hopefully it’s here by next Wednesday because I have a big, nasty, mossy, moldy driveway that’s gonna take a serious bleaching to get clean!

That last comment is the same way Guy Fieri describes food on his show.

you have to blast it with a surface cleaner first. I have an 18hp. Honda with a 6gpm pump,. and a Mosmatic SC. A smaller less powerful set up is more work and more painful. So it helps to blast as much as you can with pressure first. Then I run 12.5% bleach through the pickup and apply it with a black fan tip. I always presoak the grass or vegetation near the concrete i’m working on. I see no reason to ever pre-soak cement with bleach… Pressure then 12.5 …let that sit and it will kill everything embedded in the cement. Leave and go to the next job.

So I got a 250 gallon tank how much bleach I got a big concrete job…
What else to put in the mix:?

What’s your process going to be ?

I just got a 6gpm with 16hp engine reg wand… I just usually spray water to clean this concrete is pretty dirty thought to add a bleach…

any plans on getting a surface cleaner ? I’d get one a.s.a.p.

On this job one area is 20x40 swimming pool area, Patio and then triple garage/pea gravel drive way 60’ long…

I have a classic…

Pea gravel driveway i’d bleach first. Can be a real pain to rinse too…

I’ve done a lot of jobs and I just usually WASH WITH WATER and it all cleans up good.

Not done any steps do this 1st and this 2nd I just wash and done with it…

Sure I COULD do it better// of my 10+ jobs I never had a complaint always good job…

Just thought id add some stuff to my water to see what it does??

Pretreating lets you work faster with the surface cleaner. The point of a surfactant is to break down and loosen dirt.

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what’s the answer to my question of WHAT AND HOW MUCH do I add to my 250 gallon tank of water??