Hi...

Me and my wife wanted to replace our existing plastic shower base with a poured concrete and tile job. But talking to our last contractor he said that in order to raise the drain for the added tile height, that they would have to come in from the ceiling below to work on the pipe & drain. Couldn't they just cut the plywood flooring beneath the shower to get at the drain? Will the subflooring loose it's structural integrity if it's cut?

Thanks,

Bode

Hey Bode,
I'm assuming the pipes are PVC.
There is a way your plumber can extend the raiser without tearing into the ceiling Providing there's enough room to cut the old raiser down and couple a longer stub-up to it. It will be tight but it can be done.
Cut a hole in the subfloor smaller then the flange type shower drain,(see image) that will set on it and take a set of inside cutters,( see image) and make a cut close to the trap. If there's room he can now install a DWV coupling and extend the raiser as high as he wishes. If space does not permit this then the ceiling will have to be opened up and a new trap and raiser installed but if all it needs is the raiser extented then try my way first.
Good luxk, Tom