Shower floor tiles

[rf]

I just finished having a walk-in shower installed. The tile floor (of 2" ceramic tiles)is not pitched properly so the water puddles. The contractor wants to correct the problem by putting another layer of properly pitched grout then tiles over the improperly pitched floor. Is this OK or is it necessary to rip it up down to the concrete floor below the vinyl pan and do it over?

Thanks RF

[Charles Spitzer]

if the extra height doesn't pose problems, then doing it his way is ok. he's not using grout, but cement or thinset to pitch it properly. he should rough up the tiles a lot to get that to stick.