[frogman64]

Is there such a thing as a back flow check valve that can be installed to prevent clogged drain serving multiple units from allowing water to back up into my first floor unit's bath tub? Such a back up occurred in another unit while tennants were on vacation. Overflow from tub caused major damage including mildew, mold, carpet, subfloor, etc.

If available, how and where is it installed?

[massplumber2008]

Hey Frogman:

Yes there is a check valve that can be installed in these cases... it would be installed anywhere in the drain line going to the tub.

However, you said you are on first floor..? When the other tenant had sewer backflow... was he on 1st floor, or was his apartment in the basement..?

These kinds of things usually show up in a basement laundry area or basement apartments... but they can also show up at other floors as well.

It is not common for landlords to install these checkvalves because one or two drain lines clogged... or the main drain clogged.

In fact, not your issue really... you are a tenant right? I would recommend that you get a renter's insurance policy that covers sewer damage, etc. if you think this will happen again. I don't think landlord will hire plumber to come in, open ceiling at unit below you and install a check valve to the tub (would only force the waste to the next highest fixture anyway--->> toilet).

Fact is that if you have enough units above you and you aren't around for awhile and a sewer drain line backs up, there can be damage... NEXT APARTMENT OPT FOR UPPER FLOORS!! ;)

Hey, seriously, I understand why you are asking the question. It really is a good question. I just don't think it will help you much in this case.

Let me know what you think... Mark

[iamgrowler]

Is there such a thing as a back flow check valve that can be installed to prevent clogged drain serving multiple units from allowing water to back up into my first floor unit's bath tub? Such a back up occurred in another unit while tennants were on vacation. Overflow from tub caused major damage including mildew, mold, carpet, subfloor, etc.

If available, how and where is it installed?

You could install a backwater valve, but doing so would just push the overflow to the next highest fixture, which would likely be the toilet, after that it will be the bathroom lavatory, and then after that, the kitchen sink.

Should you decide to protect each fixture with a backwater valve, you run the risk of having the overflow plug up your vents -- And once they've plugged up, the overflow will come down the vents *PAST* the backwater valves and right up through your traps and into the fixture again.

In short, the answer is no, not without creating bigger and far worse problems.

If each unit were plumbed independently (drains and vents) of each other, then a backwater valve would be ideal, but that isn't how multi unit buildings are plumbed; Drains and vents are shared in multi unit buildings.