Help with correctly venting/plumbing drain system.

[trg]

Hoping someone can help me with a my drain venting system. Attached are pics of the current system which has no internal vent. When the septic was done, a vent was added OUTSIDE the home where the septic line exits the basement since there was nothing inside. I am gutting the bathroom and hoping to fix this. My question is how i should go about venting this, or should i leave it as is. Currently, the kitchen sink is 1.5" which goes into a 2 inch line. The bathroom sink, and washer stand pipe also go into this line. That goes into the main 4" line. The Shower goes directly into the 4" line, as does the toilet. I was thinking of basically keeping the existing style system, with putting the kitchen sink, bath sink, shower, and stand pipe into the 4" line individually. Then venting it by tapping into the 4" just after the toilet (or vent it before?), and running it up to the roof (like the attached pic). Would this be a correct way to wet vent the whole system? I would be ripping out all of the existing piping and replacing with new, using the correct sanitary tee's etc. I attached a pic of my layout to approximate where each drain needs to be. Everything is basically right over the septic line where it exits the house, except the kitchen sink. Any advice on how to figure this out would be appreciated. This is the one aspect of my renovation that has me very confused. I am in NJ and the code is NJ Uniform Construction code.

 

[frodo]

i'm busy.....i can help you tonight, friday night

 

[trg]

i'm busy.....i can help you tonight, friday night

Any help or guidance you could provide would be greatly appreciated.

 

[frodo]

rip it all out, start over.

you are going to need to open some walls upstairs for vents, there is no way around it.

even if you use an auto vent, you have to have a minimum of 1 vent out the roof.

 

[frodo]

you can use an auto vent ,,use it at the kitchen, the lav sink, and washer

run the toilet and tub out the roof

 

[trg]

you can use an auto vent ,,use it at the kitchen, the lav sink, and washer

run the toilet and tub out the roof

Yea the house will mostly be gutted which is why im taking care of this. Is it correct to vent the toilet, and shower like the 3rd pic? Just wye off, and then run a vent right to the roof? As far as stand pipe for the washing machine, can i have the trap below the floor in the basement for it? Does the AAV need to be higher than the trap, or higher than the inlet for the drain?

 

[frodo]

............

 

[trg]

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Thanks a ton frodo, i appreciate it. Few more questions. On the standpipe for the washer, does the aav need to be above the inlet? Also, since im using a pedestal sink in the bathroom, fitting an aav outside of the wall would be tough. Can i vent the sink into the attic, and connect it to the toilet vent? Or would it have to go through the roof on its own? The bath sink is on a center load bearing wall but i think im allowed to bore 40% of the stud width through the top plates. Last question is adding another standpipe in the basement for water softener. Since this drain would be below the rest of the drains, should it be plumbed in any specific way?

 

[trg]

http://www.ipscorp.com/plumbing/studor/trapvent

I wonder if something like that would meet code? I think that is compact enough that i could fit in behind my pedestal sink.

 

[frodo]

Thanks a ton Frodo, I appreciate it. Few more questions. On the standpipe for the washer, does the aav need to be above the inlet? Also, since I'm using a pedestal sink in the bathroom, fitting an AAV outside of the wall would be tough. Can I vent the sink into the attic, and connect it to the toilet vent? Or would it have to go through the roof on its own? The bath sink is on a center load bearing wall but I think I'm allowed to bore 40% of the stud width through the top plates. The last question is adding another standpipe in the basement for water softener. Since this drain would be below the rest of the drains, should it be plumbed in any specific way?

the AAV
has to be above the standpipe and exposed for maintenance
no, it can not be in the attic

put it behind a mirror, the code says accessible not readily accessible

i would pump the back wash up a low drain in the basement is trouble down the road

 

[trg]

the AAV
has to be above the standpipe and exposed for maintenance
no, it can not be in the attic

put it behind a mirror, the code says accessible not readily accessible

i would pump the back wash up a low drain in the basement is trouble down the road

Sorry for confusion, i didnt mean put the aav in the attic. If i ran a roof vent for the bath sink, could i run the pipe into the attic and then tee into the shower or toilet pipe just to minimize holes in the roof? Or would it have to go through the roof by itself? Do you think a water softener built in pump has enough lift to pump from the basement to the washing machine stand pipe the floor above or should i pump into a vessel and then use something like a condensate pump to do it?

Do you think that integrated studar trap vent would work in place of a normal p trap and aav? It looks nice and compact and would fit behind the pedestal sink i think.

Also is there any reason why i should use 3" for the drain? Its currently 4". I would think bigger is better.

 

[Mr_David]

Can i vent the sink into the attic, and connect it to the toilet vent?

Yes ! You can connect it to the toilet vent any where above the flood rim of all the fixtures shared by that vent

Or would it have to go through the roof on its own? No it would not unless you could not connect it to another vent

The bath sink is on a center load bearing wall but i think im allowed to bore 40% of the stud width through the top plates. Last question is adding another standpipe in the basement for water softener. Since this drain would be below the rest of the drains, should it be plumbed in any specific way?

Stand pipe for water softner should have a p-trap and a vent. the vent can rise up to the next floor and also connect to another vent as long as that connection is above all flood rims of fixtures above that are shared by the vent.
This is so a stoppage anywhere in the system can not back up and drain out through the vent

 

[Mr_David]

Toilet vent in your picture NOT ideal. Only if no other way due to horizontal section of vent can easily become fouled during a stoppage.
best to use a low heel outlet 90. Run the vent straight up into the wall.
come out the bottom of the LH 90 with another 90 or combo and send it any direction you want.

 

[trg]

Toilet vent in your picture NOT ideal. Only if no other way due to horizontal section of vent can easily become fouled during a stoppage.
best to use a low heel outlet 90. Run the vent straight up into the wall.
come out the bottom of the LH 90 with another 90 or combo and send it any direction you want.

Yep, i'm going to do it that way with the sanitary tee. Is there any reason to use 3" over 4" that is currently there? Also, do you know if that studor trap-vent meets code?

 

[frodo]

4'' is fine, I can not tell the difference between 3'' from 4'' in a picture

I have no idea if an auto vent is legal in your area, I do not know where you are located

call your local plumbing inspector and ask

 

[trg]

I spoke to the inspector and went over the plans. He told me a few things he needed. Thanks again for your layout frodo.

He said i can tee the shower vent into the toilet vent, but he wants the 2" where it goes into the attic adapted to 3" going out of the roof.

He also said he wants a test tee on the back of the main drain line, instead of a clean out. Im guessing the best way to do this is between the 3x3x2 sanitary tee and the 90 degree elbow like this pic:

http://i1341.photobucket.com/albums/o757/ignigokt/20150910_175648_zpsvuz6zwsl.jpg