Hi all,
After two applications of tile grout on my bathroom floor it still crumbles and comes out. Mixed according to the directions but no luck I'm about to apply third coat after removing the old.Any suggestions on what I might be doing wrong ?

Pete

What are the mixing instructions? I frequently buy the premixed grout because I'm lazy but it never fails for me. Make a small ball of your grout with just a teaspoon of water, shape it into aball and allow to set over night. Tomorrow it should be hard as a rock and not crumble, if it does return the grout to where you bought it.

Try adding some liquid vinyl component that the sell with grout. Supposed to make it more flexible.

I would start by asking what do you have under the tile? Did you install a cement board base and screw it off 4" on center? If there is any give what so ever in the sub floor your grout will not stay put no matter what you do. I always use a vinyl based grout, however, if the sub floor is not installed correctly not even god can keep the grout in place. OK OK yes he could... but you get the idea.
Good Luck,
Mike