Ask Me Help Desk - Toilet Vent

I am putting in a septic system at my cabin, there is a toilet in the bathroom that will need to be tied to this new septic system. The toilet has a 4" pipe that runs through the crawl space, under the footings and is stubbed outside the cabin. This pipe is a straight pipe with total of about 13' long. I would like to put an elbow on this pipe and run it along the outside of my foundation tying it in with a Y to the pipe that will connect the septic tank to my main drain. It would be so much easier tying in the toilet outside my foundation than working in a 16" crawl space and trying to tie the toilet into my main drain inside the foundation.

My question is, where do I vent my toilet?? Can I vent my toilet outside the foundation near where it is currently stubbed, or is this 13' run to far from the toilet? I was hoping to vent after the elbow on an outside wall then put a clean-out just before the Y connecting to the pipe coming from the septic tank.

I know I have code issues etc... This is for a seasonal cabin only and the plumbing will need to be redone when I build a year round place in a few years. The septic tank, lift, and drain-field are all sized and planned for the future cabin.

Thoughts?

Thx-Henny

Quote:

Originally Posted by Henny

I am putting in a septic system at my cabin, there is a toilet in the bathroom that will need to be tied to this new septic system. The toilet has a 4" pipe that runs through the crawl space, under the footings and is stubbed outside the cabin. This pipe is a straight pipe with total of about 13' long. I would like to put an elbow on this pipe and run it along the outside of my foundation tying it in with a Y to the pipe that will connect the septic tank to my main drain. It would be so much easier tying in the toilet outside my foundation than working in a 16" crawl space and trying to tie the toilet into my main drain inside the foundation.

My question is, where do I vent my toilet ??? Can I vent my toilet outside the foundation near where it is currently stubbed, or is this 13' run to far from the toilet ?? I was hoping to vent after the elbow on an outside wall then put a clean-out just before the Y connecting to the pipe coming from the septic tank.

I know I have code issues etc... This is for a seasonal cabin only and the plumbing will need to be redone when I build a year round place in a few years. The septic tank, lift, and drain-field are all sized and planned for the future cabin.

Thoughts ??

Thx-Henny

... to exceed 5' and water closet drains should not be allowed to pass by another unvented fixture. If during your remodel or if you have other fixtures in the cabin you have not mentioned there may be a safety issue if the closet is not allowed to vent its gasses via another fixture, fixture group or main stack. If by venting outside the cabin there is no chance of these gasses re-entering the cabin then the setup may be OK for temporary use but does not meet code (5' to vent).

You mentioned "the water closet drains should not be allowed to pass by another unvented fixture". In this case, the water closet drain would be on a separate line and tied to the main, (outside the house), before the other fixtures tie to the main. There is no main stack or any roof vents for that matter. The two sinks, (Bath & Kitchen), have P Traps and an in-line vent about 6"-12" about the traps.

If I understand you, I still should have a vent in the water closet line to vent gasses outside the house. I can run a 3" vent up the outside of the house that will be a vent for the water closet only. I know 13' is not code but neither are in-line vents. Do I gain anything by venting the water closet on the outside of the house some 13' away from the stool??

Thanks-Henny

Quote:

Originally Posted by Henny

You mentioned "the water closet drains should not be allowed to pass by another unvented fixture". In this case, the water closet drain would be on a seperate line and tied to the main, (outside the house), before the other fixtures tie to the main. There is no main stack or any roof vents for that matter. The two sinks, (Bath & Kitchen), have P Traps and an in-line vent about 6"-12" about the traps.

If I understand you, I still should have a vent in the water closet line to vent gasses outside the house. I can run a 3" vent up the outside of the house that will be a vent for the water closet only. I know 13' is not code but neither are in-line vents. Do I gain anything by venting the water closet on the outside of the house some 13' away from the stool ????

Thanks-Henny

... that this outside work was easier than the crawlspace work. What do you mean by in-line vents? Some may argue that a water closet is self-venting but this is only true if the water discharged is strong enough to carry the gas to and through the septic and somehow allow it to disperse into the air harmlessly in the leach field. Sounds a little far fetched to me. As you know, methane gas is poisonous and explosive and I would like to get it into the air as soon as possible. Next to nothing at all, 3" of vent 13' from the closet will be helpful but not nearly as good as the maximum 5' to the nearest vent.

The in-line vents are a vent that screws into the top of the vent pipe on the fixture. Example, below the sink the P Trap runs from the drain and T's into a pipe. That pipe drains through the floor one direction and extends above the P trap the other direction. Instead of this pipe venting through the roof or tieing into a stack, it extends only 6"-12" above the P Trap and has an in-line vent screwed into the top of the pipe. These vents do not meet code but are used in situations where you don't want to tear open a wall to run a vent up through the ceiling/roof.

I have a bathroom sink, shower drain, and kitchen sink all connected and draining into one 2" pipe. This is my cabins main and only drain that will be connected to the septic tank main pipe with a 4" to 2" reducer. This connection will happen inside the foundation in the crawl space under the kitchen sink. The stool has a seperate 4" pipe that exits the cabin about 10' away from where this main drain will connect to the septic tank pipe. I am proposing to run a pipe outside the cabin along the foundation and connect it to the main septic tank pipe with a Y or sanitary T. This connection happens before the connection to the cabin main so I figured I'd be good to go.

Does this make sense??

Thx-Henny

Quote:

Originally Posted by Henny

The in-line vents are a vent that screws into the top of the vent pipe on the fixture. Example, below the sink the P Trap runs from the drain and T's into a pipe. That pipe drains through the floor one direction and extends above the P trap the other direction. Instead of this pipe venting through the roof or tieing into a stack, it extends only 6"-12" above the P Trap and has an in-line vent screwed into the top of the pipe. These vents do not meet code but are used in situations where you don't want to tear open a wall to run a vent up through the ceiling/roof.

I have a bathroom sink, shower drain, and kitchen sink all connected and draining into one 2" pipe. This is my cabins main and only drain that will be connected to the septic tank main pipe with a 4" to 2" reducer. This connection will happen inside the foundation in the crawl space under the kitchen sink. The stool has a seperate 4" pipe that exits the cabin about 10' away from where this main drain will connect to the septic tank pipe. I am proposing to run a pipe outside the cabin along the foundation and connect it to the main septic tank pipe with a Y or sanitary T. This connection happens before the connection to the cabin main so I figured I'd be good to go.

Does this make sense ???

Thx-Henny

... sense and although it would be great not to have to add a vent on the toilet, it looks as though it's the 13 footer that will have to do it. Since the toilet makes for a very strong trap and a large volume of water flows when it is flushed, I suspect it will also push the gas out this vent.

Make certain the water main and the toilet are always functioning well to keep water in the toilet and the tank, thus preventing the gas from entering the house.