View Full Version : Plumbing a basement bathroom
J_ONeil
May 24, 2010, 04:23 PM
I am sure this has been asked several times, in fact I have read through many of the posts but I would like to ask about configuration for my situation.. I have attached a proposed floor plan and some pictures what I can see in the basement regarding vents/pipes.
Can someone help me understand what the pipes are in the basement that I see coming out of the floor and down from the ceiling?
I am trying to draw up a schematic of the plumbing plan; vents and drains but not sure what all of the existing pipes are. The house is almost 4 years old.
Thanks,
Joe
Milo Dolezal
May 25, 2010, 01:39 AM
Which direction do you plan on running and connecting your new waste pipe ?
massplumber2008
May 25, 2010, 04:16 AM
Hi all:
It looks to me like all the drain work is done underground... right, Joe? You're looking to run the waste and vent pipes above the floor... correct?
I'm coinfident that the 2" pipe by the shower will need to have a 2" test tee fitting (see image) installed and then you can pick up the sink waste. Here, you'll install a 2"x1.5" sanitary tee fitting at about 17.5" or so to center of the fitting off the floor so that when the 1.5" pipe ends up at the sink it will be at about 19" to center of the finish floor (you want to pitch the pipe at 1/4" per foot back toward the 2"x1.5" sanitary tee fitting. Then you'll run that 2" up and connect into the 2" vent pipe in the ceiling (called a future vent). This will effectively WET VENT the toilet, and shower and vent the bathroom sink.
The toilet pipe needs to end up at 12" to the center of the toilet pipe off the new rough stud wall. That is, when the wall gets sheetrocked the toilet will want to be at 11.5" off the finish wall to the center of the toilet pipe... OK?
I think the big question here is how are you planning on picking up that bar sink drain ? As far as you show in the pics. There is no drain pipe or vent for that bar sink. You will either need to chip out the floor and cut into the waste pipes underground to send a 2" pipe over to the bar sink...picking up the bar sink and running an 1.5" vent to connect into the other 2" vent for the bathroom, OR you can also install a laundry tray pump that can pump the water from the bar sink over to a waste pipe. The sink and the laundry pump would require separate vents... ;)
Anyway, we're glad to draw something up here, but let us know more on the bar sink and anything else we may have missed.
Mark
J_ONeil
May 25, 2010, 08:51 AM
Yes.. the bar sink is the big question.
I am thinking at this point to just run with the laundry tray pump and pump it over to the waste pipe where the sink is tied into. So as I understand it then; I will have to run a vent for the sink and the pump over to the vent that goes up through the floor. Correct?
I am assuming that I can drain into the same location as the bath sink, if so should I tie in above or below the lav sink sanitary Tee?
Kind of like this:
-| -vent from bar sink and pump (clearly not to scale)
|
|
|
|/ - lav sink sanitary tee
|
\| - bar sink sanitary tee
|
|-- - test tee
_|_______________________basement floor
I am assuming that if using the pump I can pump around the perimeter of the bath wall (behind the toilet, along the west foundation wall and over to the 3" wet vent behind the shower). Correct?
Thanks for your help.
Joe
J_ONeil
May 25, 2010, 02:52 PM
Here is a drawing I put together to layout what I was thinking. Can you critique and offer adjustments?
Thanks,
Joe
massplumber2008
May 25, 2010, 03:26 PM
Hi Joe...
The only real change that I see you need to make is to run the pump vent up and through the roof by itself. Some local inspectors may allow you to connect it to the existing vent in the attic just before it exits the building, but most frown harshly on this practice.
You will also want to connect the pump into the drain via a wye fitting, and be sure to pitch the pump's drain pipe from the highest point (above the pump) to the lowest point at the drain connection by the sink... 1/4" pitch per foot is code. Don't forget to install the check valve and a PVC shutoff just above the pump's waste line as required by code and the manufacturer...just in case you need to work on that pump in the future. Finally, most laundry pump manufacturers require that you drill a 5/32" hole in the pipe (inside the pit)just above the outlet to prevent the pump from becoming air locked... check out the instructions for your pump for best results, of course!
Let me know if you would like to discuss more...
Mark
J_ONeil
May 25, 2010, 05:30 PM
Well the vent situation is going to make me rethink this whole plan. I am more apt to dig up a portion of the floor before I start going up top as it is a 2 story home and there is no easy route up to the roof from the basement.
So then my question is can I tie the bar sink vent in with the existing vent like in my diagram. I am assuming that I will need to vent that drain.. correct?
Thanks again, you've been a big help.
Joe
massplumber2008
May 26, 2010, 04:32 AM
In a 2 story home the only way we usually get vents into the attic is to go up through a couple closets that are hopefully on top of each other. Here, we'll justify the pipe to the front left or right so that you can't see the pipe when you look into the closet.
Otherwise, if you connect into the plumbing underground, conect into the drain pipe using a wye fitting and run 2" pipe up and out of the ground. Install another 2" test tee fitting and then install a 2"x1.5" sanitary tee fitting to pick up the bar sink (1.5" here). Then you can reduce the 2" to 1.5" and connect it into the other bathroom vent pipes... so yes, you need to vent the bar sink!
Remember, to pitch the vents so that rain water that enters the system through the main vent can flow back to the drains by gravity. All pipes get hung every 4 feet.
J_ONeil
May 26, 2010, 01:21 PM
OK, I have an updated drawing and just a couple more questions;
- Can I tie into the waste line from the toilet?
- If so can I actually insert a wye fitting at the toilet pipe under the floor and install that way; effectively putting the toilet 'downstream' from the bar sink.
I will definitely pitch the vent pipes as well (specifically those from the bar sink as they have the longest runs. I haven't cut into the floor yet so I still have no clue what is under there. But I am assuming it's like a 3" drain line under the concrete.. is that a safe assumption?
Thanks again.
Joe
massplumber2008
May 27, 2010, 04:26 AM
You can't really take off the end of the pipe like that at the toilet. Instead, install a WYE fitting about 1-2 feet behind the toilet elbow. Roll the wye fitting slightly above the center line of the drain pipe and you can use the bar sink drain/vent to act as a WET VENT for the toilet... ;)
You'll need to open the floor to know the pipe size, but my guess is that you have 4" underground.
That should do it! Keep me posted...
Mark
J_ONeil
May 27, 2010, 01:38 PM
Mark,
Thanks again. When you say "behind the toilet"; do you mean like I have indicated in the drawing with the dashed lines?
massplumber2008
May 27, 2010, 06:57 PM
I can see where you would think that... ;) I meant for you to install a wye fitting in just behind the elbow as in my red drawing below. Let me know if this makes sense now?
I also added another older drawing showing the same thing except, in your case, you will run the vent to join the other vents as you drew it up earlier. Don't forget the 2" test tee (not shown here) just after you come out of the ground... OK?
Mark