Pipe banging and causing what looks to be waste water leaking

Apologies in advance for not knowing exactly what these things are, but I am hoping the pictures attached can help.

In the basement beneath the stairs I have what looks to be a main drain pipe as well as a vent, these go into something in the floor for wastewater to drain into. Again, sorry for the terrible explanation.

Typically when something is draining, although not always, the drain pipe bangs and noticeably moves, which over time has caused some leakage around where it enters the floor. As I am sure you can imagine, the smell is pretty bad and can linger in the hallway. Not to mention any potential health hazards from the leakage.

As far as I can tell it is no single thing causing the banging. I have heard it happen with the basement toilet, washing machine, also in the basement, but also heard it happen while upstairs and with what I assume nothing draining in the basement.

I have read about using water hammer arrestors, but would I need to install one on anything that causes the banging? Initially, I would likely put one on the washing machine and basement toilet, then see if that stops all of the banging, if not try to track down what else causes it.

So, going on the assumption that a hammer arrestor will stop the banging. my next thing is how do I correctly seal the pipe where it goes into the floor to stop any additional liquid / smells coming out.

Thanks.

 

So what is in the pit, looks like a sump/grinder, must be a motor down there. Clearly the one fitting needs to be tightened/replaced!

 

Yes, you have a sump/ejector pit. There is a submerssible pump and float switch that turns on when the chamber gets full and it pumps the waste up to the sewer. The banging you hear is the swelled or fat section of pipe. It's a check valve. When the pump shuts off and the water in the pipe starts flowing back down the pipe the check valve slams shut.

As for the leak is looks like the coupling has a bad joint. You might need to cut out both couplings and replace them with two new ones and a short nibblet of pipe or use a no-hub coupling.

 

Thanks Pilot Dane, is there any way to quiet the check valve? or is it just something to live with. The whole section of pipe jumps when it bangs which is why I think that coupling started leaking in the first place.

Is there a reason for there being 2 couplings like that? Looking at my picture 20180410_094954 the pipe looks slightly crooked between the 2. I suspect the plumber could not line the discharge pipe from the pump up with the pipe coming down from above so used a small piece at a slight angle to make it work.

What would be the better option to repair? 2 new couplings and a small section of pipe, or the no-hub coupling? If the check valve is always going to cause the pipe to move, I want as few points of possible failure as possible. Assuming when I want to carry out the repair I just need to shut off power to the pump (and tell the family to not use any water for a period of time).

Looking into things a little more, I wonder if it makes sense to just go ahead and replace the pump itself (it is about 10 years old), the lid, check valve and piping between them both. Just need to determine which pump I should get... any recommendations on both the pump and check valve appreciated. THanks.

 

There isn't much you can do to the check valve but you can wrap it in insulation to quiet the sound. You can also install bracing and clamp the pipe to provide more support which could help prevent it from breaking fittings loose.

I assume the couplings are from when someone had to work on the pit. As you can see there is no room to remove the lid. The gasket around the pipe will not slide over a fitting so the only way to remove the lid is to cut the pipe. It's no big deal. PVC is cheap and easy to glue together. I would get a male adapter, a few feet of pipe and a new coupling. Cut the pipe just above the top coupling and throw away everything below. Glue the male adapter onto the end of the pipe and lift the sump lid and insert the pipe up through the grommet and screw it onto your pump. Cut the pipe to length and re-connect to the existing piping with the coupling.

I would not replace the pump unless it fails. A good pump will be at least several hundred dollars and your existing pump could have another 10 or 20 years left... or it could die tomorrow. I would NOT replace your working pump with a store brand one from a big box home center as what's in your pit now is probably better quality.

 

Great, thank you. Sounds simple enough. My wife will be happiest not to have the stink that it currently causes!!

 

I would echo Pilot Dane's suggestion:
I think a 2x4 between the two walls with a 2" pipe bracket to better secure the pipe in one or two places will really help the banging.

Every time the pump turns on/off, it creates a bunch of force on the pipe both twisting it a bit, and also the push of water/waste in the pipe. Right now, the pipe is bouncing around - which is both probably making a bang, as well as potentially loosening any connection. That movement probably contributed to the connection issue you have at the bottom pipe with the leakage.

 

That's not a bad idea at all, I might have to put a second piece of 2x4 on the one side horizontally between the vertical frame pieces. But, can then attach a new piece of 2x4 with the pipe bracket to hold the pipe in place nicely.

 

I like Pilot Dane's plan overall, but making the replacement connection with a no-hub would allow future examination/inspection without having to cut the pipe again.