Construction Contractors Community

CleanTeam · Joined: 23 Sep 2007 Posts: 6

I read the post by Barry on a great tool for cleaning cement, but how about cleaners? What do you guys use for cleaning concrete like driveways and so on? I am new to the business and still learning so any advice from experienced pros would be very helpful. Thanks in advance.

expertwasher · Joined: 23 Sep 2007 Posts: 12 Location: Maryland

I would also like to know what everyone uses. I have my own mix but that is not to say that someone doesn't have something better. I have found that homemade cleaners work better than anything I've found in the stores.

Barry M · Joined: 05 Sep 2007 Posts: 90 Location: Indiana

For residential driveways, patios, sidewalks, and pool decks 99% of the time I use my regular house wash mix (12% chlorine and soap). The chlorine will take care of tannin stains caused from sticks and leaves and will also kill any mold and mildew. The soap it obviously for the dirt and grime. I use a downstream injector and apply the chems at low pressure with my pressure washer. I'll mix 4 gallons of 12% chlorine and 1 gallon of house wash soap in a 5 gallon bucket. Stick the chem hose in the bucket and coat the cement, let it dwell for a couple minutes and start washing using cold water, hot water might speed up the cleaning process a little but IMO its off set by the extra fuel cost to run the burner. Rinse well after washing to get all the dirt and debris washed off.

For gum removal on commercial jobs I'll do the same as above and then go back with hot water and a 15degree tip and start peeling up gum where needed.

For oil stains on driveways caused from an oil leak from a vehicle I've always used pressuretek's F13 and some hot water. In the past I've also had some luck with full strength Purple Power from Wal Mart. With oil stains most of the time, depending on how old the stain is, there will still be a shadow left on the cement no matter what you use to clean it. A good rule of thumb is to use sodium meta silicate on petroleum based oil stains and potassium hydroxide on animal or vegetable type oil stains like you would find around a restaurant dumpster pad.

As far as rust stains go with cleaning concrete, I've only had luck removing irrigation rust stains. All other rust stains like the ones caused from a metal chair sitting on cement or from a radiator leak are extremely tough to impossible to get off. With irrigation rust on cement I wash the surface like mentioned above, rinse well, and then I will apply a mix of water and oxalic acid. Ox comes in powder form and is sometimes sold as deck brightener (same thing) pressure tek sells some called F 8. I will mix 4 pounds of it to 5 gallons of water and apply with an xjet. Let it dwell and the rust will just disappear, rinse well, and your done. If your going to downstream it then just mix it stronger, if your going to apply it straight using a pump up sprayer or something similar then mix it a little weaker. Pressuretek also sells xjet and downstream injectors if your wandering.

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Pressure Washing Contractor Providing Deck Cleaning, Concrete Cleaning and Other Power Washing Contractor Services

Jeannie · Joined: 27 Oct 2007 Posts: 82

Fantastic information on cleaning supplies that should be used and what your mix is. Very easy to make and sounds like it does the job. I simply enjoy reading everyones information as it is very useful even for those of us that want help in other areas of our business.

Bryan C · Joined: 17 Nov 2007 Posts: 13

As Barry mentioned, a good commercial cleaner added with hot water, will usually do a great job. There are the occasional rust or oil stain shadows that remain, but it will still look a lot better...

sealerguy · Joined: 20 Feb 2008 Posts: 3

If your in a pinch and cant locate any oxalic acid, home depot sells a product called rust - aid , it works fairly well on medium surface rust. Seems to melt right off. Normally I just use my phosphoric acid, and that works too.