Floor-level shower - is backflow from the toilet "normal"?

Hello forum,

In our new single-family house, we have problems with our floor-level shower on the upper floor.

After some time, we have unpleasant deposits under the shower's trap (clearly things from the toilet - which is connected to the same wastewater pipe - T-connection, i.e. toilet and shower are directly next to each other).

After I pointed this out to the plumbing company, I was told that a certain backflow from the toilet is normal (because of the floor-level shower) and nothing to complain about. It is recommended to clean thoroughly every two months!

I don't have to accept this answer, do I? A test with "substitute liquid" clearly showed that the stuff reaches the shower.

Regards NemoN

P.S. The house was planned and built by a general contractor. We have not signed any liability waivers.

Hello,

I don't have to accept this answer, do I?

I'm not really a plumbing person, but no - you don't have to accept that. Because if it were "so normal," no one would choose the T-arrangement anymore. I would suspect that something went wrong during the rough installation.

Have you already moved in and the acceptance has therefore taken place? Have you informed your general contractor about this situation? If not, you should write to him and request an inspection and remediation; he owes you the warranty, although he may pass it on. If he does not respond, send a defect notice with a deadline and only if this proves fruitless, request a cost estimate from an external plumbing company. Then inform your general contractor about this and only if there is no response, commission the external plumbing company. You can then pass these costs on to your general contractor.

However, I assume that your general contractor is also interested in counting satisfied builders among his clientele; so he will react.

Rhine regards

Hello construction expert,

thank you for the hints. That is how I will do it!

Regards
NemoN