When our contractor poured the concrete for sidewalks and handicap ramp, concrete splashed onto the vinyl siding. Is there a product or way to remove this more easily than hand-scrubbing? Pressure washing did not work.

  • Is getting the contractor back to clean up their mess no an option? Seems like their responsibility.
    – JPhi1618
    Commented Sep 27, 2019 at 14:42
  • No. Unfortunately the contractor has sustained a back injury and is out of commission for the foreseeable future.
    – peinal
    Commented Sep 27, 2019 at 14:51
  • Understood, just wanted to get the obvious out of the way. Any chance of posting a picture? The extent of the problem might be important for certain solutions.
    – JPhi1618
    Commented Sep 27, 2019 at 14:53
  • I will try to do so at my 1st opportunity. It'll probably be Monday. But, til then--suffice it to say it is significant on the first 12-24".
    – peinal
    Commented Sep 27, 2019 at 14:59

1 Answer 1


If [the concrete] has set, soaking the concrete with a strong detergent solution helps loosen its adhesion so you can scrub or scrape it off. Georgia-Pacific recommends mixing the following ingredients to make a strong cleaning solution for vinyl siding:

1/3 cup detergent
2/3 cup trisodium phosphate
1 gallon water

Scrub with a soft-bristle brush or scrape with a plastic paint scraper. To give the scraper more leverage, wedge it underneath a concrete deposit and tap it with a hammer; this usually makes the concrete pop off.

If you have a concrete deposit that just won't budge, muriatic acid is sure to dissolve it. If, on the other hand, the concrete is spread over too wide an area to make scraping, scrubbing or washing by hand impractical, you can opt for a pressure washer, but check the siding product warranty to be sure you won't void it by pressure-washing. Both options should be considered last resorts.

Using Muriatic Acid

Step 1 Put on goggles and rubber gloves to protect yourself from the corrosive effects of muriatic acid. Mix one part acid with three parts water in a bucket to create a 25 percent solution.

Step 2 Test the acid solution before using it. It's safe for vinyl, but your siding may not be 100 percent vinyl. If it's safe, spread it liberally in the concrete with a natural-bristle paint brush. Don't use a synthetic-bristle brush -- the acid dissolves the bristles.

Step 3 Allow the mixture to dissolve the concrete. It may take several minutes, and you may have to apply more. As the concrete dissolves, wash it off with a garden hose.

Step 4 Clean off the residue with a kitchen scouring pad. Use the pad only after rinsing to avoid dissolving it in acid.


  • Where does one obtain trisodium phosphate?
    – peinal
    Commented Sep 27, 2019 at 15:30
  • 1
    It's commonly available at hardware stores as a cleaning agent. Might be labeled "TSP".
    – isherwood
    Commented Sep 27, 2019 at 15:33

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