Belly or too little slope?

[lawwatchscotch]

Getting my basement finished and had my sewer line cameraed to get ahead of any issues. It's 4 inch PVC under slab installed in 2020 by a company I no longer have confidence in. The camera identified a belly in a section of the pipe that was holding water and submerged the camera, but minimal waste. Plumber initially said not to fix it, but I'm worried about it causing a problem later and having to rip out a portion of the newly finished basement.

It's accessible and easy to get to now, if it's worth it. We excavated the nearest fittings to get depths and determined that there's space to create roughly 1 inch of fall over that 20 foot section, which is under the 1/4 code requirement.

Will that relatively minimal fall be better than the belly such that it makes sense to fix? I have to assume that taking the belly out so it's all at least sloped the right way is better than doing nothing? The plumber is the plumber doing my basement and I trust him - he's also doing it at a cut rate so the expense isn't an issue and he's not making much money on it at all.

 

[Jeff H Young]

actually comes out to 1/20th ipf slope pretty flat . raise that end 2 inches youd be good and take that belly out . might as well fix it right . sorry the plumber is doing poorly on the job that sucks

 

[Sponsor]

 

[Breplum]

Absolutely, you should address the situation. Code will allow 1/8 inch per foot for 4" pipe. You've got crap.
In minimal fall situations, we would use highly compacted base and switch to cast iron to insure no belly. Plastic is way prone to not being straight right off the shelf.

 

[Tuttles Revenge]

I would recommend fixing the belly now while the upside cost is the lowest.

the IPC allows 1/8th slope on 3" pipe.

We had a job recently repairing some major bellies in the slab of a home that was quite extensive to fix. Caused by poor backfill material. The sewer backup in the house caused some really expensive damage and repair.

On another project that was exterior sewer, we hired a company that used a vibrating cable to remove the belly in a buried drain without excavation.

 

[Jeff H Young]

Absolutely, you should address the situation. Code will allow 1/8 inch per foot for 4" pipe. You've got crap.
In minimal fall situations, we would use highly compacted base and switch to cast iron to insure no belly. Plastic is way prone to not being straight right off the shelf.

Ive never put cast iron in like you mention, but I really like that Idea a couple sticks of 4 inch wont break the bank! but abs is so damn bowed its impossible to fight . nice and flat you can get away a little under Im hoping he dosent have a bathroom rough in to tear out but whatever it takes just do it once !

 

[lawwatchscotch]

Thank you, everyone. Unfortunately increasing the slope to 1/4 inch/foot wasn't an option because the lines extend on boths ides of this section and we just don't have the budget to rip it all out again 4 years after paying 30k to a plumber who did it poorly. The good news is we excavated the section today and found a joint that had been unsupported was causing the belly. We replaced with solid PVC and new, good, compacted backfill to support it, and managed to get 1/8 fall. I feel pretty good about it, I think, even if I'm annoyed that the original company did such a poor job.

 

[Jeff H Young]

great 4 binch all you need is 1/8 th and you have that but I was going off the statement o that you had 1 inch fall in 20 feet 1/8 inch is 2 1/2 inches in 2o ft . 1/8 inch is no worry at all

 

[lawwatchscotch]

great 4 binch all you need is 1/8 th and you have that but I was going off the statement o that you had 1 inch fall in 20 feet 1/8 inch is 2 1/2 inches in 2o ft . 1/8 inch is no worry at all

Totally - When the plumber eyeballed the measurements before we got it fully excavated he thought it might be 1 inch total fall over the 20 feet. Once we got it opened up we realized we could do more! Thank you!