I hired a cut rate concrete contractor to redo my driveway because all the bigger firms were too busy. He did a decent job, but he did a couple things that I now need to fix since the chances of seeing him again are about zero.

First, he used red chalk line to mark his cuts on the slab-- it rained the next day and now I have red stains all over my driveway. I tried scrubbing with simple green and using a power washer, but the stains are still there. Is there any way to clean this?

chalk stain

Second, he was just plain sloppy when pouring the cement, and splashed the mud on the aluminum siding of my garage. How can I remove the cement from the aluminum siding without scratching it up or needing to repaint it?


Finally, he and left small rough areas on the already screeded slab where his "helper" walked on it and didn't re-screed. Can I use a sanding disk to sand down the rough areas on the slab?


  • Is it a brush finish surface or a hard troweled surface? How long has it been down? Could you post a picture, especially a close up of the foot print
    – Jack
    Jun 26, 2018 at 5:25
  • @Jack it's a brush finish. I'll post pictures when it gets light. Thanks!
    – user101289
    Jun 26, 2018 at 6:06
  • I say leave the driveway surface alone at this point. Sanding might make the area slick, lower the coefficient of friction, and heighten the difference. Only an expert would know what to do that would not make the situation worse. Maybe the chalk lines will become obscured by progressive mottling and darkening of the surface. An elderly guy in my neighborhood was unhappy with cracks that had to be repaired in a new driveway and in the end the contractor stained the entire driveway to obscure the repaired cracks. Jun 26, 2018 at 8:52
  • sun will cleanup those red marks for you. eventually. might try bleach or hydrochloric acid to speed it along.
    – dandavis
    Jun 26, 2018 at 21:00
  • The footprints look as if cement is deposited on the surface of the concrete, not impressions as I would have thought at first. Which is the case, impression, or deposit?
    – Jack
    Jun 28, 2018 at 2:58

1 Answer 1


Mix CLR and water and apply to the chalk line. Brush with a stiff brush, wipe up the residue, and rinse. Works perfectly every time, for me at least.

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