QUESTIONMy contractor bought two different types of grout, one sanded and the other unsanded, in the same brand and color. The tiler used them side-by-side (not mixed together) on one wall. Will the difference in materials be noticeable in the end? Should I ask them to redo the work?
ANSWERANSWER - Unsanded cementitious grout should only be used in grout joint widths of 1/8 inch or smaller. If you use it in wider grout joints it will tend to crack.
Sanded grout should be used in grout joints that are 1/8 inch wide or wider. It won't fit into the grout joint to fully fill it if the grout joint is narrower.
If the tile is the same type of tile and the installer installed one wall with sanded grout and the other wall with unsanded grout that is odd and doesn't make sense. Unless he started with one and realized it was the wrong type. If so he should redo the one that is incorrect.
If the grout joint is 1/8 inch wide then you can use either sanded or unsanded grout, but the installer would be expected to use the same one in the entire installation. The only difference in this case is the aesthetic appearance that would may or may not be noticeable to most people.