Designing Kitchens and Bathrooms - grout vs silicone the floor/wall returns

I have recently had the floors and wall in my bathroom retiled and had all the spaced between the tiles grouted with the exception of the space where the floor meets the wall (floor wall return). Is it OK to have this grouted as well or is it better to have this sealed with siolicone.... does it matter? As a side note, the corners where the 2 walls meet have been siliconed.

Thank you.

Floors/walls expand in different directions at different rates, no way grout will last in those joints. Caulk is usually the best there. And there are colored caulks available to match grout colors.

http://www.sashcocontractor.com/Contractors/Mor_Flexx.aspx

I've been playing with this stuff here at the lumber yard and it's awesome. Strong (I stuck two big cement bricks together with it--not a recommended use I guess) and flexible. Very crazy stuff. Unfortunately, it looks like mortar, not necessarily grout. Is you grout mortar colored?

We're selling this for under $5 a tube, not sure how much you'd pay in your area, but check it out.

Don't try and reinvent the wheel. As suggested by bill, they make color matched caulks that will make this joint blend right in with the rest of the grout. It is the right product for the job.

I thought the same thing (ie it is better to have the edges where the walls and floor meet siliconed), However, the builder that's organised the bathroom renovations is saying...
"... grouting of the floor / wall returns are always done by using sand and cement. Silicon in this area tends to go black and mouldy. All floor / wall returns have been fully waterproofed. Water cannot penetrate through to the tile screed or to the sub strata. Siliconing the returns has absolutely no waterproofing advantage."

What would be your response to that?

Waterproofing is not the issue here. The walls and floor will move independently, and this will result in cracked grout over time, thus the need for caulk instead of grout.:)