Roughing in toilet & sink

**TontoYoder** · 12-25-2010, 10:43 AM

I'm an amateur at plumbing, but customers have asked me to add 1/2 bath to ground floor.
They had the foresight to plan for an eventual toilet, so there was 4" pipe and a closet bend capped off under the concrete slab that I've chipped away.
The 4" pipe is at a 45∘ angle from rear wall and the closet bend turns upward 12" from the existing rear wall.

Since I'm adding a rear wall of 2X3s to hide the plumbing from an added vanity, I have to adjust the 12" distance from the new wall.
I also don't want the toilet upstream from the vanity right? So, apparently I need to go in a somewhat roundabout way to make the sink connection?
Could folks check the proposed diagram to see if I'm doing this correctly?

**cacher_chick** · 12-25-2010, 04:21 PM

Your existing plumbing might have the water closet vented through the lavatory.

Your drawing fails as there are no vents shown on either fixture. You also cannot have a section of pipe upstream of the fixtures as it would harbor waste after a backup. It would make more sense if the WC was at the end of the line. Without knowing how the WC was intended to be vented, you are stabbing in the dark.

**TontoYoder** · 12-25-2010, 05:49 PM

Originally Posted by cacher_chick

Your existing plumbing might have the water closet vented through the lavatory.

Thanks, but I'm not sure what you mean. The existing plumbing here is merely PVC pipe in a concrete slab and I don't know if they were planning for a sink or not. Since it's a slab, it's difficult to go exploring.

Your drawing fails as there are no vents shown on either fixture. You also cannot have a section of pipe upstream of the fixtures as it would harbor waste after a backup. It would make more sense if the WC was at the end of the line. Without knowing how the WC was intended to be vented, you are stabbing in the dark.

"Stabbing in the dark" is pretty much how I feel, so I'm here looking for help.
I've expressed my concern about the venting, but the customers seem unconcerned. There's a nearby vertical stack that services the master bath above, so they're assuming the drain in the slab connects to that stack and would be vented through it.
I have considered doing a back vent on the sink that would run over and tie into that vertical stack---I assume that stack continues up through the first floor into the attic and vents through the roof (I CAN access the attic and check that). At least that would be something I could SEE and be certain it was installed, but I didn't want the extra expense and labor if it was redundant.

I DO see your point about avoiding extra pipe upstream of the fixtures, so I'll avoid that.
I was just trying to add a cleanout somewhere in the new work, but I guess I could hide one in the proposed vanity.

I'm still confused about the suggestion of the WC being at the "end of the line". I thought that would put the WC upstream of the sink (which I thought I needed to avoid).

Thanks for any input.

**cacher_chick** · 12-25-2010, 07:39 PM

You should start by familiarizing yourself with the plumbing code that is in effect in your area. You will need to apply for a permit, which will require a complete isometric drawing of the drain and vent systems. This will need to be approved by the building inspector, who will later inspect and witness test(s) of your installation to ensure that it is compliant.

In many states, only a licensed plumber can perform the type of install you are looking at. Other states add the exception that a homeowner can perform work on his her own residence. The plumbing code, permits, and inspections all must take place either way.

hj · 12-26-2010, 07:06 AM

The term "customer" implies that YOU must be a contractor of some kind, but not a plumbing contractor, since doing this kind of work, ALWAYS requires a contractor with a license and a permit. IF this is the case, then you are normally, NOT qualified to do the plumbing, and the building department would NOT issue a plumbing permit until a licensed plumber applies for it. Doing it yourself, especially without ANY plumbing experience, can open you up to many bad things, starting with the fact, that when you get done, the homeowner can refuse to pay you, and the courts would side with them.

**jadnashua** · 12-26-2010, 10:47 AM

As mentioned, in many places, the work must be done either by the homeowner OR a licensed plumber (and requires a permit and inspection(s)). In some places, even the homeowner isn't authorized to do plumbing, even in their own house (Massachusetts is one place like that). Not saying that it doesn't happen, just that you open up all sorts of potential legal problems if you Do do it. A drain (normally) cannot be used as a vent, so you can't tie into the vertical stack unless you run the new vent line above the highest flood plane of any drains above it.

**TontoYoder** · 12-26-2010, 12:48 PM

Originally Posted by jadnashua

..... A drain (normally) cannot be used as a vent, so you can't tie into the vertical stack unless you run the new vent line above the highest flood plane of any drains above it.

In this particular community, there's a good deal of work that's done without observing requirements.
I have already suggested that they should have a plumber do the work, but I guess I'll have to be more insistent.
Thanks for clarifying the vent/ vertical stack issue---I think I had the concept right, but I had the height wrong: any added vent would have had to connect in the attic in this particular house(though that WOULD have avoided poking another hole in the roof).

**Terry** · 12-26-2010, 01:10 PM

Your worst customer is one that insists that a cheaper way with short cuts is all they will pay for. And then when the ***X hits the fan, they don't want to pay.
When the job is done right, there can't be a complaint.
Code books are fairly thick, and for a reason. There is a known way that plumbing works, and no good reason to shortcut it.
They way you have been drawing it, won't pass any inspection I know of. But's it's a very simple job for a journeyman plumber. Easier to do sometimes, then it is to teach.

**TontoYoder** · 12-26-2010, 02:13 PM

There seems to be an over-emphasis from the plumbers on the customers not PAYING, but
there's absolutely no question whether they would pay or not.

My concern has always been getting the fixtures to work properly.

**Terry** · 12-26-2010, 03:21 PM

Our point, is that the job should be correct and pass inspection.
I realize that there are many contractors out there that are doing electrical and plumbing.
I looked at a bath remodel for a real estate agent on his home, his bargain plumber (handyman without a license) had plumbed the new master bath without any venting. Needless to say, it was interesting how the shower filled up with black goo everytime the soaking tub drained.
And yes, he got paid for that kind of work. So yes, it doesn't matter that much I guess.

**Gary Swart** · 12-26-2010, 03:42 PM

Well Tonto, you seem concerned that you don't have the knowledge or skill to do this right and the customer doesn't want to be for a skilled plumber to do the job. Here's a novel idea. Tell the customer NO, I don't know how to do it right, and I won't risk my reputation by doing it wrong. Yeah, you might lose this customer, but perhaps you'd be better off without him. Just a thought.