Redoing a bad job on concrete staining.

by Kimber
(Dyersburg TN)

Q. My contractor did a horrible job on staining my concrete. I have several spots (huge in width) that are uncolored and he said it was impossible to color those spots due to the fact that it wouldn't take the color. Is there any way to undo or redo this job so that I may get a better result?
Thank you

A. If the stain was cut with water (most are) try using it full strength. Sometimes the concrete is power troweled so smooth the surface is very dense and the acid stain needs to be used full strength for it to etch the surface and deposit the color. You may also have to apply it twice to get the desired color you want.

You could also try sanding the area with a palm sander and a fine grit sand paper to open some of the pores in the concrete before you stain it.