:o Hello,
We just had our first rough plumbing inspection and the inspector did not like the way I was thinking of venting a shower stall. We are roughing in plumbing for a ground level bathroom where the piping will be under concrete. In one corner of the bath we want to install a 38" neo-angle shower. This is in a corner formed by the foundation which is ~3' tall here and ~12" thick. Using the correct fall of 1" in 4' the drain line will be about 7" below the finished floor. I can not figure out how to vent this stall. Does the vent have to come before or after the P-trap? From reading, a vent line has to intersect a horizontal drain line at no less than a 45 deg angle... If there some way to tie a vent into the P-trap and run it under the shower (horizontally) :oand then up behind the shower (if I fur out the wall for it).
Help!!
Daniel Neuman
Oakland CA

Good morning Daniel, I'm not about to go head to head with a plumbing inspector on his own turf. :o He has the last word. :-X However I can make a few suggestions ;D. Are you close enough to tie into the lavatory drain? Since most bathroom groups vent from the lavatory this would vent the shower as well as the group. Or you could stay within 5' downstream of the trap and roll up a drainage tee on a 45 degree angle and level it out with a street 1/8 bend. That puts you on a horizontal plane and you could run over and up the wall you're going to fur out. Try running that by your inspector. ;) Good luck, Tom

Hello,
I was originally going to tie the shower pan and sink together. The sink riser is about ~4' from the shower pan riser. I was planning on using 3" drain line and tie the two toghether with a wye and run a 2" vent on the lav. Downstream from this would be a wye branch for the toilet which would be vented through a 2" vent and the two vents would tie into one 2" outside and go up through the roof overhang. The inspector did not like this set up.? He said the shower is not wet-vented he said it was not vented at all... I need to qualify this as the inspector was not the 'official' plumbing inspector but a less qualified fill-in... so he might be wrong.
How exactly would you tie into the lav drain?
Any help you can give would be greatly appreciated.

p.s. does anybody know what the headheight has to be over a toilet that is under a stairway? I am getting different numbers from different people.. 7' 6'6" or 6'? Anybody know?
Daniel Neuman
Oakland CA

I don't see why the inspector had a problem with the original layout. To my way of thinking the vent you ran on the toilet wasn't necessary. The lav vent should have vented the entire bathroom group. Let me call your attention to section 1412.1 of the Standard Plumbing Code entitled "Wet venting, single bathroom groups." A single bathroom group of fixtures may be installed with the drain from a back-vented lavatory, kitchen sink or combination fixture serving as a wet vent for a bath tub or shower stall and for the water closet provided that:
(a) not more then one fixture unit is drained into a 1 1/2" diameter wet vent or more then four fixture units drain into a 2" diameter wet vent.
(b) The horizontal branch connects to the stack at the same level as the water closet drain or below the water closet drain when installed on the top floor. It may also connect to the closet bend.
Your layout would seem to fit in here. I would tie into the lav drain the same way you would. The height of a toilet enclosure should be addressed in your local building code. We just worry about them sitting down, not standing up. ;D If you can't any satisfaction out of your inspector take your plans down to the building department and clear it with the head plumbing inspector. Good luck, Tom

Hello,
What the inspector was saying was that it was not a wet vent. He said a wet vent is when a drain from one fixture drains into the vent of another fixture. What I believe we are talking about here is me tying the shower drain into the drain of the lav with a wye as close to the vent as possible. I was thinking that if I used 3" abs and a 2" backvent on the lav that that would be fine... he didn't think so. I will have to look up which version of the plumbing codes are in effect here in Oakland CA and then maybe go see the head man... its such bad karma to piss an inspector though...
Daniel Neuman
Oakland CA

What the inspector was saying was that it was not a wet vent. He said a wet vent is when a drain from one fixture drains into the vent of another fixture.

Silly me! And here for the last 50 years or so I must have been reading the code book wrong. A wet vent occurs when the drain of a fixture drains into the "DRAIN" of a fixture that is vented. This is one inspector I wouldn't mind going head to head with. Take your plans down to the building department and clear it with the chief inspector. And then request another inspector to inspect your job. Good luck, Tom

?? Well I have not been able to get ahold of the head plumbing inspector... I think that is by design. I have my rough plumbing inspection this Monday 14th so I am just going to go for it.
Another thing that popped up. Are you allowed to run the pipes so that they will be imbeded in the concrete? One of the inspectors told me that they were only allowed to penetrate the concrete but the lateral runs could not. I don't have the fall for this. I know that the plumbing has to be wrapped in that foam stuff where ever its in contact with concrete. The contractor that is doing the slab pour says they do it all the time and thinks the inspector is crazy.
Now you are telling me I only need one vent from the toilet to do the entire thing... boy that would be easier..
Now the plan is to vent the lav and shower stall with 1.5" ABS while their drains will be 2" and this branch drain will meet with a 3" wye. The toilet will be vented with a 2" line which will meet up with both 1.5" lines before going outside. Then I will switch to copper DWV pipe to go up the three stories to my roof. How does that sound.
Daniel Neuman
Oakland CA

Not exactly what I said.  You will have to vent the lavatory not the toilet to be in code.  From the lavatory vent with 2" not 1 1/2".    Is the water closet downstream or up stream from the lavatory?  I can find nothing in the code book to outlaw laying a branch in the slab.  Section 410.1, (Breakage and Corrosion) of the Standard Plumbing Code book states, "  Pipes passing THROUGH or under cinder or concrete or other corrosion material shall be protected against external corrosion by protective coating, wrapping or other means which will prevent corrosion."  Since your pipes are PVC  I  don't see where corrosion would be a problem, however local codes may forbid it.  You did pick up a copy of the local plumbing code from the Building Department didn't you?  Why are you converting to DWV copper to go upwith the vent?  Why not just extend the 2"PVC vent up from the lavatory?  If there ia a reason, please let me in on it. Regards, Tom

:) I'm sorry I hope I am not being too much of a pain...
The bath is a small upside down L shaped room. The shower is at the corner of the L, the lav is at the end of the short side and the WC is at the end of the long side. The WC is on the downstream side.
Since the inspector wants to see vents on everything then I plan on only using 1.5" vents for the lav and shower. I think that is all that's required by code?
I am using ABS not PVC plumbing. Here in Oakland they will not let you run any ABS when it is exposed. You can run it underground, in slab but not exposed to sunlight... They force us to switch to metal or cast iron when you run things externally. I chose the copper because its MUCH lighter for a 3-story vent than cast iron. I will run all the vents in ABS and then switch to copper when it penetrates the exterior wall.
I asked about getting a copy of the plumbing codes and they looked at me like my head was on fire. :-[
Hope this clears my conundrum up a bit.
Thanks for the advice.
Daniel Neuman
Oakland CA

I don't see how you can possibly do your own plumbing without a copy of the local codes that you must work under. This is becoming really weird, WE went to PVC from ABS thirty years ago. A vent for each fixture? Did you quote the sections of the plumbing code that I gave you and what did they reply. If the building department ignores the Strandard Codes and substitute local restrictions you MUST DEMAND a copy of the local codes or you are flying blind. As a home owner and a taxpaying citizen it is unfair that they force you to work with out a set of guide lines. Force you to use ABS? Vent every fixture? Prohibit plastic pipe from external use? Oakland may call that,"a plumbing job", here on the West coast of Florida we call that a "abortion" Please keep me in the loop on this. I want to kinow how you make out. Regards, Tom

:o Had my inspection with the 'real' plumbing inspector today. He was a nice-friendly guy who teaches a plumbing class at the local community college. He also ripped me a bit. I used sanitary T's to vent horizontal drain lines and he says I have to take them out and use a combo-wye. I also made a couple stupid mistakes and rant a couple vent Wyes in the wrong direction.
I asked him which code they go by. He said that Californias plumbing code is based on the UPC not the IPC but in CA lots of sections have been deleted and different sections added. I think he said UPC, is there such a thing? I asked where I could get a copy, he said a specialty bookstore and its over 100 bucks!
I asked about the wet vents and he said 'has to be vertical' you can not wet vent horizontally.
CA must be behind the times as PVC is not used. Even the pro plumbing supply places don't really carry it. Its mostly used around here for sprinklers and inground drainage. He REALLY did not want ABS used externally. I have some exterior drainage stuff run in ABS and he was having a fit about it. I had to keep telling him its just the roof runoff not the plumbing and that I would paint it to match the house and then it would last.
All I got to say it AAAAARGH!! >:( >:(
I am so screwed, cause we got the 'wrong' inspectors twice before my slab pour is two weeks behind schedule.
Hope this answered all your questions speedball.
Daniel Neuman
Oakland CA

Hey Daniel, PICKY! PICKY! Your inspectors just got to be the worst. I got to repeat this from The Standard Plumbing Code, (and by the way, UPC= Universal Plumbing Code) Let me call your attention to section 1412.1 of the Standard Plumbing Code entitled "Wet venting, single bathroom groups." A single bathroom group of fixtures may be installed with the drain from a back-vented lavatory, kitchen sink or combination fixture serving as a wet vent for a bath tub or shower stall and for the water closet provided that:
(a) not more then one fixture unit is drained into a 1 1/2" diameter wet vent or more then four fixture units drain into a 2" diameter wet vent.
(b) The horizontal branch connects to the stack at the same level as the water closet drain or below the water closet drain when installed on the top floor. It may also connect to the closet bend. Now drain= horizontal drainage line. A "vertical" wet vent just doesn't make any sense at all. But it's his turf. If they wish to ignore the codes that most of us work under I guess they can do it but I feel sorry for the plumbers that have to comply with it. I can see why they don't want ABS used outside. One of the reasons that we haven't used ABS for over thirty years is because under the hot Florida sun it would lose its ridgitedity and a horizontal run, like from the kitchen stack to the stub out, would just become limp and sag down losing pitch. PVC schedule 40 has a thicker wall and being white doesn't absorb as much heat. Good luck with your project. I'm sorry that my opinions differ from your inspectors but for the last 50 years I've worked up and down Floridas West Coast under countless local code restrictions and have never run into a Mickey Mouse set of local codes like you are under. Please keep me informed of any more codes that you have that set plumbing back thirty years. Regards, Tom