AOE: Water damage and backwater valves

A few years ago my rental home experienced what I like to call an “adverse ownership event”.  In my book, an AOE is the kind of thing that makes you wish you were a renter and not a homeowner.  While I love home ownersihp, there are the occasional incidents that make me wish I could just call a land lord and say “this is your problem”.

My AOE was a sewer line flood of my basement rental unit.  My renter was home and out of nowhere, the sewer line started backing up into his unit.  He called me and I had to get to work dealing with it.  Luckily, he noticed a Roto Rooter truck at the neighbors house, my neighbors had cleared their sewer line and it had jammed further down and blocked my line.  This was luck for me because it meant I could show my insurance company that someone else was responsible which means they’d pay for the damage (more on this in a later post).  The reason my neighbors could affect me like this is because we are on a shared side sewer.  The side sewer is the sewer line that connects your home to the city main line.  It is the homeowners responsibility to maintain the side sewer, in a shared side sewer situation, multiple homes use the same side sewer line.
When the sewer line backed up I ran to the house and got the Roto Rooter guys to clear the blockage all the way down to the sewer main so that the sewer line to my house would start to drain again.  Next up I had to call a water damage company, you’ve seen the commercials on TV, these are the companies that claim to make things like it never happened.  When dealing with sewage, anything the waste water touches has to be removed, all of the dry wall, wood paneling, carpet, etc…
The water damage people removed the carpet, the bottom 6 inches of the wood paneling, and the drywall.  Unfortunately they couldn’t remove the floor tiles because they contained asbestos.  I had a specialist company come out to remove that (thankfully insurance paid!).
The basement unit was extremely old, at least 30-40 years so I used this as an opportunity to redo the basement unit and modernize the kitchen and bathroom.  My main concern at this point was, how do I keep this from happening again?

The answer to this question is pretty straight forward, I have basically two options, I can redo the sewer to my house so that I’m not sharing it with anyone else which would be way too expensive for me to justify, or, I could install a backwater valve.
A backwater valve is a one way valve that lets sewage go out, but prevents it from coming back into the house.  It’s an extremely simple device and not expensive, mine is a $200 valve I bought at backwater-valves.com.  The valve has a plastic gate in it which floats, if water flows back in then it will automatically raise the gate and keep water from going back into the house.  Once this happens, the only danger we have is that someone in the house will run water and fill the pipe.  To prevent this from happening, we attached an alarm to the backwater valve so that we know when the valve has stopped.
When the alarm goes off, the tenants call me and I call someone to clear out the sewer line.  Easy and I sleep much better at night knowing this won’t happen again.
Installing a backwater valve can be tricky, you need to  install it between the point where your house sewage drains and where the  shared line starts.  This usually means digging down fairly deep to install it, in my case, it meant my contractor renting a jackhammer and installing it in my basement.