View Full Version : Need to understand venting my bathroom drains
taysan
Mar 15, 2008, 06:44 PM
We're about to embark on a full gut/reno of our main bathroom. I will be hiring a professional plumber to make the small changes we need to do to the supply and drains, but I want to make sure I understand what they should be doing :)
It's a 10 x 8 foot room as shown in the attached diagram. This is more or less the layout as it is now. Sink and toilet are not moving and have been in place for the 8 years we've owned the house. The tub and shower drains are more or less where they are in the diagram. I have not opened the floors so am only guessing at how the drain pipes are configured. The main stack is in the corner as shown and vents to the outside through the roof directly above the bathroom.
Is this configuration proper? Are the drain runs too long? How does the shower vent in this situation?
massplumber2008
Mar 16, 2008, 04:41 AM
Hey Taysan:
Without knowing what is under floor I can't tell you exactly what should be what.. ok?
Most likely, however, the main underground line is straight shot from stack to toilet(3 or 4"). Then, the sink and tub are piped so that the tub and the toilet are WET VENTED by the sink(2" pipe for all this). The shower will need to have its own vent(2" out of ground reduced to 1.5 inches above ground). The wet vent and the shower vent connect at 6 inches higher then the rim of the sink and should connect back into the stack in corner. This is best case... unknown if it is what is under your floor, of course. Vents pitch from stack back toward the drains always!
If it is a straight shot over to the toilet that tub may also need an individual vent... may not, but note that it may... depends on how deep the pipes are. Anyway, let me know if you need more... Mark.
.
speedball1
Mar 16, 2008, 05:15 AM
Perhaps I'm a little dense this morning but in your drawing, are you showing the vents or the drains. The line going to the stack. Is it a drain or a vent?
If it's a vent then all the fixtures appear to be individually vented which is just dandy. However, If you're showing us the drain and the only vent is the lav armed out to the vent stack then I have a major problem with your layout.
1)The shower's unvented. 2) your discharging a major fixture, (your toilet) past a unvented minor one,(your tub). Perhaps I'm looking at this all wrong, if I am post back and tell me where I took the wrong turn. Regards, Tom
massplumber2008
Mar 16, 2008, 05:23 AM
Tom:
My guess on this was that he drew what he thinks the WASTE line does underground (has not exposed yet)... I stated that a plumber would probably not do what he presented. Most plumbers,as you know ;) , would run from stack straight over to toilet and then go from there. Anyway, that is how I saw it.
Taysan... what is it.. Let us know... Now you have two plumbers guessing!
.
taysan
Mar 16, 2008, 01:17 PM
To clarify, these are what I think are the waste lines - this is the 2nd floor of my house, and I will be ripping up the floor boards and re-doing some/all the lines.
So, being that I will be ripping up the floor, I suppose my question would be what SHOULD the waste and vent lines look like for a room with the fixtures located as per the labels in my drawing.
The walls and ceiling will also be opened up, so I have an opportunity to take new vents into the ceiling and either over to the stack or directly through the roof (which of course I'd rather not have to do).
The wall on the right of the drawing is a partition wall and will have the plumbing for the shower in it. The walls at the top and left of the box are exterior solid brick walls. There is a bulkhead around the stack in the upper left corner.
The supply for the tub will come up through the floor as it is a clawfoot tub with a deck mount faucet mounted in the center of the tub.
Here's a better image of the planned layout. Sink and toilet are remaining where they are today. Right now the tub and shower are reversed, with a corner tub where the new corner shower will be, and a corner shower where the new clawfoot is going.
massplumber2008
Mar 16, 2008, 02:01 PM
Taysan:
Much will depend on exactly how the drain pipes are laid out upstairs... and that all depends on direction joists face... but for now...
I gave you basic layout of bathroom like this in last post... (except now pipe for tiolet will not run straight over to toilet... will follow joist bay).
I figure pipe comes straight out like your first drawing, then 3" long sweep 90 into toilet drain. The 2" waste line for the lavatory can act as a wet vent for the toilet (this vent stays 2" all the way back to the stack) The shower will need its own vent (1.5") and looks like the tub will too (1.5"). These will connect together 1.5" and then run over to the stack as well. All vents connect into stack at least 6 inches higher then the height of the sink top.
Hope that helped. If it did, please RATE THIS ANSWER... Thank you... Mark.
Let us know if you need more... ;)