Twowaxhack, I've not cleaned any house drains. As an engineer, I deal with engineering principles. The issue here is not a code issue, but what would provide the best choice for a system that would work for this situation. As there is no flow in the upper stack connection, the "venting" would better be served using a wye. And if the "loop vent" approach would be installed here, I would do away with the AAV as the compressible air in the vent will suffice for any pressure/vacuum problems caused by the flow down the stack. And after further thinking, I would actually suggest a full 4" wye for that connection which would provide a larger surface access to the air entrained in the flow down the vertical stack. A 4"x2" bushing in the "vent" wye and 2" pipe as you suggest would round out a better workable system than your sketch. In my professional opinion.
Adding utility sink to basement. Any code issues? Help? I
- Thread starter Bomaifam
- Start date
Help Support Plumbing Forums:
You can’t compress air in a plumbing vent system. It’ll blow water out of the ptrap or bubble.
Goodbye, forever.
Goodbye, forever.
In this case, Twowaxhack, we are talking mm of water pressure, not inches of water pressure for this installation. And as your design has the same issue with compressing the air in the "vent system", I'm not sure why you don't understand that the more air in the "vent loop" you have, the less pressure that will be exerted on the water in the trap. Nor do you appear to understand that the larger surface area you have at the top "vent" connection using a 4"x4"x4" wye, the better access the "vent" has to the air in that vertical run. And this design would not require an AAV, although you could put one in at the top of the "loop vent" if you really thought it would be a benefit.
This is the difference between "plumbing theory" and actual "engineering principles".
Bomaifam, Based on Twowaxhack's "Goodbye, forever" comment, he may have blocked me. So do as you like and use whatever design you deem has more merit. He is a Professional Plumber, and I am a Professional Engineer. This is not a code issue as neither of these designs meet the code. One last thing that needs to be checked. As this building has an upper and lower unit, my assumption is that the basement is common. And from your pictures, I'm assuming that both units share the same sewer outlet where you are wanting to install this sink. If that is the case, when you start into this project, be sure you coordinate with your upstairs neighbors and that you have everything you need to complete the job in a short amount of time.
One suggestion would be to pre-fabricate an assembly including a new cleanout with the two 2" stubs capped off. Something like the sketch below. Then all you need to do is to cut the existing stack in two places and install the assembly with a couple of shielded rubber couplings. The sink and all associated piping up to the capped stubs could then be installed at your leisure, instead of in an urgent time frame for the entire job. Then at a second short "shutdown" of the sewer system will allow you to make those two final connections.
Good luck and God bless.
Thank you for the detailed diagram. Sorry guys didn't mean to stir up an argument i appreciate the input from everyone. Yeah i plan on letting my tenants know not to flush any toilets and i will turn of the water from the valve in the basement as well while i work. That's a great idea to fab it all up and then just install the whole section at once to minimize downtime. I planned on just pvc gluing the whole thing but some 4" rubber couplings would be even easier and leave me with my pipe for when i remove it down the road.
I would turn the water off and have the other unit flush their toilets. You still have one flush after the water is off. At least one flush, sometimes two.
Then cut the section out of the 4”. I’d reuse the clean out and the existing 4” pipe. You should actually have 4” pipe left over.
This way you don’t have to buy 4” pipe.
There’s no argument, I do this for a living 35 yrs + in fact I own the business and I’m the 3rd generation master plumber and we’ve been in business for over 90 yrs.
So let everyone have their opinion and I’ll sit here with my facts.
Good luck brother
Then cut the section out of the 4”. I’d reuse the clean out and the existing 4” pipe. You should actually have 4” pipe left over.
This way you don’t have to buy 4” pipe.
There’s no argument, I do this for a living 35 yrs + in fact I own the business and I’m the 3rd generation master plumber and we’ve been in business for over 90 yrs.
So let everyone have their opinion and I’ll sit here with my facts.
Good luck brother
Twowaxhack is right, there’s no argument, just the difference in opinion on this non-code installation. His 35+ yrs using "plumbing theory" and my 45+ yrs using actual "engineering principles". Both opinions will probably work, but I would opt for the one with a larger margin of safety.
And as Twowaxhack said, make sure the upstairs people flush their toilets after the water is turned off. And asking them to hold the flush lever down until the water stops flowing into the toilet would also better keep any residual water from coming down from their level.
As I suggested, use "shielded rubber couplings" for this assembly, not just the rubber ones with a couple of hose clamps holding it in place. Any of the big box stores have both kinds. And if you keep the assemble you cut out intact, you could still just use the "shielded rubber couplings" for that reinstall. There are no code issues for the use of those, and that would save you a ton of work when you go to leave. No gluing anything; just loosen the rubber coupling clamps, slide them down and up, reinsert the old assembly, slide them back into position, tighten up the clamps and walk away. Job done.
Good plumbing!
And as Twowaxhack said, make sure the upstairs people flush their toilets after the water is turned off. And asking them to hold the flush lever down until the water stops flowing into the toilet would also better keep any residual water from coming down from their level.
As I suggested, use "shielded rubber couplings" for this assembly, not just the rubber ones with a couple of hose clamps holding it in place. Any of the big box stores have both kinds. And if you keep the assemble you cut out intact, you could still just use the "shielded rubber couplings" for that reinstall. There are no code issues for the use of those, and that would save you a ton of work when you go to leave. No gluing anything; just loosen the rubber coupling clamps, slide them down and up, reinsert the old assembly, slide them back into position, tighten up the clamps and walk away. Job done.
Good plumbing!
In my opinion, this 4x2 tee should be a 4x2 long turn wye. Just my opinion though.
Finished it up. Ran all the faucets in both units and didn't have any issues with air pressure. The tee that goes to the trap ended up being a lot higher than i thought and was too high for the sink legs. They Were pretty flimsy anyway so i just made a wooden frame for the sink. I wanted a 2" drain for the sink because it will be draining a lot of solid stuff and didn't want any clogs. So i put a shower drain in it instead with a 2" outlet. I fabed everything up like you said ahead of time and just cut out the old section and clamped it in its place. For some reason every supply store near me was out of 4" cleanouts so i used a 4" sanitary tee with a bushing with internal threads and installed a plug.
Attachments
Looks great. Just remember this is not to code and needs to be replaced before any inspection by the AHJ (Authority Having Jurisdiction).
Right. I saved the old pipe with the cleanout so if needed i can just clamp it right back in
Those type rubber couplings will not pass a home inspection in my area, or a plumbing inspection. So that may or may not be a factor when you reinstall the old section.
Thanks good to know. I left enough pipe that i could gglue some couplings on so I'll just do that to be safe when the time comes
That would be best.
