Adding a toilet - Plumbing/Venting ?s

[35k0]

I have septic and water stubbed up in the front corner of my garage, the intent was to eventually put a bathroom in the loft, on the other end of the building and this is where the vent pipe is stubbed through the roof.
The reason I didn't stub the septic line up under where the bathroom will be upstairs is that we didn't have enough drop to the septic tanks from that end of the slab.
We won't be finishing the upstairs loft any time soon, so I decided to build a small bathroom, but I decided late, like after the main garage area was finished and after the roof was done. I don't want to poke another hole in my roof if I don't have to. I know, I know, poor planning on part....

To install the toilet and keep the waste stack going upstairs, I was planning to Tee-off the stub and use a rear flush toilet directly into Tee and into the septic stack.
Would you just use an air admittance vent for the main floor toilet/sink or would you direct vent up to the other end of the building and go into that roof vent (can you have a couple 45s and a long sloped run in a vent?

 

[FMB4]

Many states and counties are very strict on septic systems and modifications on them. That said, I'd make sure that you can do the above while still meeting code.

 

[35k0]

Many states and counties are very strict on septic systems and modifications on them. That said, I'd make sure that you can do the above while still meeting code.

Township inspector told me that once the house is up, the permits are approved, final inspection is completed, you can do what you want in regard of plumbing.
Our septic was also sized up for this.

 

[dcg9381]

Township inspector told me that once the house is up, the permits are approved, final inspection is completed, you can do what you want in regard of plumbing.
Our septic was also sized up for this.

That's true here too, there are not further inspections, nor is a new permit needed for plumbing modifications.
Upon resale, we have to certify that the original septic plan and associated inspection is "unmodified" and the liability for signing that remains with the signer past the sale. IE - check into resale. I'd be relatively easy to figure out that I connected "something else" that doesn't match the original certificate to occupy.

We've got an oversized septic system too, but I'm "stuck" and cannot connect anything else to it without re-engaging the permitting and re-inspection process for septic if I hook anything up to it.

 

[35k0]

That's true here too, there are not further inspections, nor is a new permit needed for plumbing modifications.
Upon resale, we have to certify that the original septic plan and associated inspection is "unmodified" and the liability for signing that remains with the signer past the sale. IE - check into resale. I'd be relatively easy to figure out that I connected "something else" that doesn't match the original certificate to occupy.

We've got an oversized septic system too, but I'm "stuck" and cannot connect anything else to it without re-engaging the permitting and re-inspection process for septic if I hook anything up to it.

Thanks for the reply, I am aware and I guess we will address that if we ever decide to sell or move, which is unlikely unless we fall on hard times.

 

[zippyslug31]

I guess we will address that if we ever decide to sell or move, which is unlikely

It's not really a case of whether or not it will have to be addressed, but much more a case of when. Even if you spend the rest of your life there, whoever has to deal with your estate (i.e. your family) would still need to deal with that complication at that time.

Might be best just to do the work, still have the inspector come out and revisit (even though it's already "finaled") and get something in writing that he's good with the work.

 

[nadogail]

Best to pull a permit and get it inspected. If you don’t, when it will need to be brought up to “code “ you will be on the hook for really big bucks.

 

[Sawlog]

Vent to atmosphere, as long as you keep vent going uphill your good. 22.5, 45,60,90’s it don’t matter on a vent.

 

[Sawlog]

A septic system is not sized per bathroom, they are sized per bedroom

 

[35k0]

All great advice, I’ll see what they say.

Fwiw it’s a new system, 3 bed home, septic designer was aware we would add bedrooms when we finish the basement as we had already installed the ejector pit.
The design is a 1500 gallon split tank with a 500 gallon pump tank pumping up to a mound.

 

[FMB4]

All great advice, I’ll see what they say.

Fwiw it’s a new system, 3 bed home, septic designer was aware we would add bedrooms when we finish the basement as we had already installed the ejector pit.
The design is a 1500 gallon split tank with a 500 gallon pump tank pumping up to a mound.

That's good news. Btw, we were on a newly built 3/2 home septic system for ~ 9 yrs. Had pumped once during that time (just 2 of use live in the place). Never had problem, but we did use some of 'septic' treatments several times a year. We also went out of our way to avoid using the kitchen disposal unit.

 

[Skooterj]

Vent pipes can run horizontally any distance as long as they have no chance of filling with water. Even when horizontal, rainwater will drain into your septic system when the pipe begins to accumulate water. If I were you, I would just run a vertical pipe straight up from the basement into the attic space above the loft, then horizontally across the attic to the existing vent through the roof. Slope it if you can, but you do not have to. I wouldn't even worry about elbows, PVC is flexible enough to bend an inch across the length of your attic. So up, a 90, across, another 90, done.

 

[Jackfre]

If you don’t vent it adequately, and I think air admittance valves are for a sink, not a WC, you are quite likely making a new hobby for yourself. Buy a high quality drain snake and make sure the clean-out if easily accessed.

 

[haveissues]

My shop mini bathroom is going in with an air admittance valve and without a permit. If the house gets sold one day I'll just rip it out and the next guy can figure it out if he wants a bathroom in the shop. FWIW, I have heard some towns look for new vents popping through roofs.

 

[35k0]

Thank you everyone, I appreciate the responses and all the suggestions.