Water dripping from bathroom into dining room. Help!

[marcolinux271]

We remodeled our bathroom with tiles and marble in the shower last January.
Yesterday my wife took a shower and the water instead of going down the drain started coming up. I tried to pump the drain and debris and sand (maybe grout) came out. It took a while before the water went away.
I decided to take a shower in the other bathroom and, right after, that sewege water started dripping through the ceiling into the dining room downstairs.
The plumber that came said that all upstairs is clogged up because of the debris, sand, etc., but the builder that remodeled the bathroom said that's not the problem.
Any advice?

[LonnythePlumber]

There should be no sand or debri in the drain. Sounds like the builder and tile guy used your drains for a trash bin. I do not believe the plumber put the builders trash in your drain.

[jimbo]

Well, tile guys have been known to rinse out mortar and grout buckets, and this sounds like it may be a problem.

However, a clog and a leak are two different things. Please clarify. Is the leak coming from the newly tiles shower, or the bathroom you don't use?