Hi there?
The shower in my basement has been overflowing with smelly ?sewer? Or dirty water
At least 3 times a week 8 months after it was built by a contractor. (we hardly used the shower since it was first built). It started probably once a week and is worse now. The city inspected and advised it is "not their problem". My contractor claimed he did put in a "U" tube when he installed the shower. Should we remove the entire shower and jack it higher so we can have a deeper "U" tube to prevent the sewer from flowing backward? Or what may be the problem?

Hey Joe,

A deeper trap won't stop the backups. This is caused by a blockage or poor drainage. I don't think raising the shower or tearing up the floor5 would help, however, they make a backflow preventer,(see image) for floor drains that you might try. Check them out at;
Flood guards for floor drains - check valve to prevent flooding from FAMOUS PLUMBING SUPPLY (http://www.plumbingsupply.com/floodguard.html) Good luck, Tom