Finishing Basement - Bathroom /Laundry Room Plumbing

[HereInOhio]

I’m finishing my basement and looking for help of how you would plumb the drain and venting for the laundry room and bathroom. I have a gray water pit I will install a sewage ejection pump since the sewage exits the house around chest level. I also don’t mind moving the bathroom fixtures around if it makes the plumbing easier/better. I tried searching the forums before bothering you but couldn't find what I'm looking for, any help would be greatly appreciated.

Key:
Yellow Rectangle- Vanity
Orange/Brown Oval – Toilet
Dark Blue Rectangle – Tub/Shower
Red Box – Sewage exits house at chest level
Diagonal Lines in Green – Washer Dryer
Dark Gray Circle – Rainwater Sump
Blue Circle – Sewage Ejection Basin
Blue Line – Assumption of where drainage will run to sewage ejection basin

*Note – 2” vent will be located around the red box. I will tie into a 3” stack above the flood level of the 1st floor, nothing else goes into that stack above.

At the bottom and to the right there's little dashes in the picture, those represent 1' each and should be to scale for distance.

 

[HereInOhio]

Is there something I could do differently to get more feedback? Assuming it's because I'm asking too much for help designing the complete layout? If I break down my specific questions would that be preferred? I have no problem doing so but was trying to avoid asking a bunch of questions and then having an answer make me rework the plan and having to ask similar questions for my layout.

If it would be preferred my first question is once I break up the concrete how do you guys hook up your toilet drainage/vent.? In my mind there's the two options I listed below.

Picture 1: I don't think will work because the vent has to go horizontal below the flood plane or the pipe would have to be extremely deep to maintain the 45 degree vent to the wall. I asked in a similar situation about putting a long sweep tee laid on its back and having the pipe extend to the wall where it would 90 up to a vent but thought it was considered a horizontal vent and/or the vent wasn't downstream of the toilet.

Picture 2: is the only alternative I can think of to have the vent connect vertically to the toilet drainage. This seems like it would have the drain pipe start pretty deep so by the time it get's to the basin it would be pretty low. Maybe I'm wrong.

Am I missing an easier way to run/vent a toilet with a long run such as this?

Thanks!

 

[Sponsor]

 

[James Henry]

The first drawing you posted is indecipherable. hand draw a floor plan with your proposed drain lines and someone will give you advice.

 

[Tuttles Revenge]

This is how I would design your basement plumbing. Horizontal wet vent the bathroom . This is the shallowest, simplest way to plumb it. The laundry ties in downstream. Everything ties into a sump which is Vented separately through the roof.. the sump must have a vent. The pump should have PVC pressure pipe and connect to a 4" drain.

 

[HereInOhio]

This is how I would design your basement plumbing. Horizontal wet vent the bathroom . This is the shallowest, simplest way to plumb it. The laundry ties in downstream. Everything ties into a sump which is Vented separately through the roof.. the sump must have a vent. The pump should have PVC pressure pipe and connect to a 4" drain.

View attachment 71106

Perfect, Thank you!!

Just to clarify the 2" vent connects to the vanity showing at the top of the drawing and vents the other fixtures besides the ejection basin? For some reason I thought that each fixture needed to be vented between it and the next fixture so I was going to run a 2" vent pipe along the ceiling and drop down to each fixture but your layout would definitely be easier.

• Would 3" pressure PVC be sufficient for the main drain line/wet vent in the layout above (the rest of the house main lines are 3") or do I need 4" to make the wet venting work?

• For the basin the discharge pipe is 2" so I will use pressure pipe which feeds into 3" PVC which exits the house. Don't think I have much of a choice here since the 3" is already ran. I do think this switches to 4" right outside the house but inside the house it's 3".

• For the basin vent it would be really hard to get this to vent on its own out the top of the house. Could I tie into the 2" vent serving as a vent for the rest of the fixtures showing here (which eventually goes to the 3" stack exiting the roof of the house).

• The original 3" stack pipe in the house now only has a 2nd floor shower that ties into it lower on the 1st floor. My intentions were to tie into this (42" to be above the flood level) and it would be above where the shower joins it. IF I could just tie in the 3" in the basement where that pipe connects to the rest of the drainage it would be a lot easier. Would this be an acceptable wet vent to service the layout above including the basin pit since it's essentially a 3" line servicing only a shower?

Thanks again!

 

[Jeff H Young]

I think 3 inch gravity drain to the pit is good. pumping can be 2 inch but should tie into 4 inch gravity drainage (possible 3 inch legal not sure I thought 4 inch minimum youll need to verify) There is a simple plan Tuttles drew up. probebly the easiest least digging as well

 

[Tuttles Revenge]

Perfect, Thank you!!

Just to clarify the 2" vent connects to the vanity showing at the top of the drawing and vents the other fixtures besides the ejection basin? For some reason I thought that each fixture needed to be vented between it and the next fixture so I was going to run a 2" vent pipe along the ceiling and drop down to each fixture but your layout would definitely be easier.
-That design is called Horizontal Wet Venting. You'll need to read more on the whys and hows.. but its an approved method to use the upper portion of a horizontal piping system as a vent for a bathroom group. The single wet vent of the sink drain is sufficient for the bathroom group.

• Would 3" pressure PVC be sufficient for the main drain line/wet vent in the layout above (the rest of the house main lines are 3") or do I need 4" to make the wet venting work? The size of the pipe is determined by the drainage fixture load and the horizontal wet vent drainage fixture load. 3" pipe is sufficient for this particular application. The size of the drain going to the sink would only need to be sized at 2", but in this case it should be 3" in order to have a full sized end of the line clean out at the wall. Then the rest of the drain and vent is sized for the fixture load. The gravity system throughout your entire system can be done with DWV rated pipe.

• For the basin the discharge pipe is 2" so I will use pressure pipe which feeds into 3" PVC which exits the house. Don't think I have much of a choice here since the 3" is already ran. I do think this switches to 4" right outside the house but inside the house it's 3". The discharge piping from the sewage ejector pump and ALL components must be 2" min. Must be pressure rated and must connect to a pipe that meets the min requirement of the rated discharge of your pump, typically 4". You may get a variation from the code if you ask your Jurisdiction Having Authority... the inspector or permit dept etc.

• For the basin vent it would be really hard to get this to vent on its own out the top of the house. Could I tie into the 2" vent serving as a vent for the rest of the fixtures showing here (which eventually goes to the 3" stack exiting the roof of the house). The UPC code says the vent must terminate on its own.. or may be combined with other vents.. I don't know what code you're under and I don't know other codes well enough to give specific advice. BUT the importance of a vent on a sump is 1. It allows the air inside to escape as water is displacing it from upstream fixtures. 2. It allows air to enter as the pump discharges without sucking the traps dry from the upstream fixtures.

• The original 3" stack pipe in the house now only has a 2nd floor shower that ties into it lower on the 1st floor. My intentions were to tie into this (42" to be above the flood level) and it would be above where the shower joins it. IF I could just tie in the 3" in the basement where that pipe connects to the rest of the drainage it would be a lot easier. Would this be an acceptable wet vent to service the layout above including the basin pit since it's essentially a 3" line servicing only a shower?

Thanks again!

 

[HereInOhio]

Thank you for your reply! This will allow me to map it out on the floor and start cutting the concrete as I figure out the rest.

Thank you!

 

[HereInOhio]

Duplicate

 

[HereInOhio]

It looks like under the IPC the ejector pump can be vented the same as other gravity systems. For the basin I purchased (Zoeller 1910-009) it is 82 gpm at 5' raise and 100 gpm at no rise. The discharge pipe will come up from the pit around 7' before connecting to the drain so I figure around 70 gpm.

View attachment 71137

Now I need to find out if I can just vent from the 3" main stack right in the basement or if I need to get to above where the shower connects. I would have the the discharge connect to the drain though a different line than the one I intend to use as a wet vent. That is a 3" wet vent and only is serving to discharge a tub = 3 dfu's. According to 912.3 I can have 12 dfu's if I'm reading this correctly. Can anyone help me here?


As far as the drainage my hands are tied because it's already 3" in the house and would be a lot to redo since there are a bunch of connections when it enters the house.

Looking at the IPC a 3" drain with a 1/8" slope can handle 36 dfu's. 4" bumps it up to 180.

Looking at IPC 709.1 to determine the DFU's I came up with about 18 but the sump is a big question mark.
8 for the bathroom which is higher than the 5-6 for the bathroom group to be safe.
The washer is 2 more
A sink in the laundry room (originally left out) would be another 2
The tub upstairs adds another 3
Sump under 709.2 since it uses 2" would count as 3 dfu's but under section 712.4.2 for the capacity it says 1 gpm = 2 dfu's so that would be around 140 dfu's alone.

I feel like I'm running myself in circles!

 

[wwhitney]

Tuttle's layout is good. The distance of the branch drain from the basement wall is up to you--you could line up with the ejector pit, or you could choose based on ease of connecting the WC to it. The IPC would allows a 1-1/2" lav dry vent to vent the WC and tub, but 2" is good.

You are going to need (4) dry vent takeoffs--one for the bathroom group (lav/WC/tub), one for the utility sink you didn't draw, one for the washing machine stand pipe (unless your washing machine is next to the utility sink and you just discharge into it), and one for the ejector basin.

Those dry vents can combine within the basement in any pattern you like, as long as any connection is at least 6" above the flood rim level of any the fixtures served by the vents being connected. The combined vent needs to go through the roof without ever seeing any drainage from any fixture through it. [No vertical wet venting between stories.] In upper stories, it can combine with vents from other fixtures, again as long as the connection is at least 6" above the flood rim level of the fixtures involved.

BTW, how many WCs total in the house?

Cheers, Wayne

 

[HereInOhio]

The combined vent needs to go through the roof without ever seeing any drainage from any fixture through it. [No vertical wet venting between stories.]

BTW, how many WCs total in the house?

Cheers, Wayne

Awesome. I was really hoping I could vent to the 3” pipe in the basement. It wouldn’t make a difference if I connected it along a horizontal run vs. the vertical portion correct?

As far as the WC’s there’s two currently and this will be the third.

The house has a bathroom on the 2nd story and it’s own vent in the back of the house. There’s the main bathroom on the first floor and the WC vents through the original stack via 1 1/2” pvc but drains into the pipe coming from the upstairs WC/lav. The 2” drain from the 2nd floor tub runs vertical down the 1st floor bathroom wall and drains into the original stack by the floor before turning horizontal running 12’ along the basement ceiling where it exits the house. This is also where everything discussed above will drain into.

It may be easier for me to separate the 2nd floor tub from the main stack and run it’s own 2” drain the rest of the way eliminating any water going through the main stack and allowing me to vent where I’m trying to.

 

[wwhitney]

Awesome. I was really hoping I could vent to the 3” pipe in the basement. It wouldn’t make a difference if I connected it along a horizontal run vs. the vertical portion correct?

Nope. If it's getting drainage from the floor above, it's not a dry vent for your basement fixtures. If it weren't for the ejector pit, you could use an AAV. But as I understand it, the ejector pit needs an atmospheric vent.

Cheers, Wayne

 

[HereInOhio]

Nope. If it's getting drainage from the floor above, it's not a dry vent for your basement fixtures. If it weren't for the ejector pit, you could use an AAV. But as I understand it, the ejector pit needs an atmospheric vent.

Cheers, Wayne

Finally getting around to this project, again. I opened up the wall on the first floor and planning on tying into the main 3" stack at a point where it will be a dry vent (nothing will drain into it from above) and above the flood line (42" from the floor). The first picture is the existing plumbing, I circled in red where I am planning on tying into it via the second picture. Hopefully this is sufficient to keep everything vented as well as adding another vent for the new stuff in the basement (bathroom, laundry room, laundry sink and ejector pump).

Just to clarify, can the ejector pump 2" vent share the venting with the rest of the fixtures being vented in the basement - or in other words have one 2" vent running to the basement to vent everything?

Note: the first floor soaking tub and WC are already vented with separate 1.5" vents or I would've used 2".

 

[wwhitney]

above the flood line (42" from the floor).

Just to be clear, at any joint between vents, the joint should be 6" above the flood rim level of all the fixtures vented by the joining vents. So 42" would be the requirement when the highest fixture on the vents being joined is a sink in a 36" high counter.

As to the ejector pump vent, I think you can join it like any other vent, but I'm not so familiar with ejector pumps. I suggest checking the pump's manual.

Cheers, Wayne

 

[HereInOhio]

Just to be clear, at any joint between vents, the joint should be 6" above the flood rim level of all the fixtures vented by the joining vents. So 42" would be the requirement when the highest fixture on the vents being joined is a sink in a 36" high counter.

As to the ejector pump vent, I think you can join it like any other vent, but I'm not so familiar with ejector pumps. I suggest checking the pump's manual.

Cheers, Wayne

Thanks! I was aware that venting couldn't run horizontally until above the flood line but I didn't know they couldn't join each other until at the same height. I thought if it was a 45 degree or greater connection it would still be considered vertical and assumed they could be joined lower, good to know!

The highest fixture in the first floor bathroom is the sink which is now a vessel bowl type and lower than the standard sink. That being said I know the toilet vent showing in the picture running horizontally wasn't above the old flood line and most likely not 6" above the new connection. I was hoping even though the vent for the toilet is slightly too low that it would be unlikely to be problematic especially with connecting it the way I am and the connection going vertical to get to the correct height before joining the main stack. That is a load bearing wall and I am concerned with drilling new, higher holes through all of the studs along it so I'm leaning towards leaving the existing vent where it is at and doing the best I can to make what I'm doing as correct as I can.

 

[wwhitney]

Thanks! I was aware that venting couldn't run horizontally until above the flood line but I didn't know they couldn't join each other until at the same height. I thought if it was a 45 degree or greater connection it would still be considered vertical and assumed they could be joined lower, good to know!

I think both requirements are based on "what happens if a fixture drain clogs just after the vent takeoff?" Waste can back up to at least the flood rim level of the fixture. That waste should stay in a vertical vent pipe dedicated to the one fixture. If the waste hits a horizontal vent pipe, then it might not drain fully when the clog is resolved, some could remain and obstruct the vent. If it hits another fixture's vent, then it would flow into that vent and foul that fixture's vent.

Cheers, Wayne

 

[HereInOhio]

This is how I would design your basement plumbing. Horizontal wet vent the bathroom . This is the shallowest, simplest way to plumb it. The laundry ties in downstream. Everything ties into a sump which is Vented separately through the roof.. the sump must have a vent. The pump should have PVC pressure pipe and connect to a 4" drain.

View attachment 71106

Hi Again! I finally got the rest of the basement insulated, studded out, electrical ran and some drywall going up today. The walls where the laundry and bathroom is going finalized, I wish I knew an interior designer!

After scratching my head a bunch I thought there is no reason (I can think of) to break up an extra 15' of concrete to get to the existing hole in the ground just to send the sewage back to where it's coming from. Ideally I will just break up the floor right under where the drain exit's the house and install the ejection pump below that. This would allow me to break up 5' of concrete vs. 25'. Any reason this wouldn't be doable?

The first picture is the old layout. If I could move highlighted ejection pump to where the green circle is in the second picture would you be able to recommend the way you would run the plumbing for that layout?

It's worth mentioned that if it would be a better layout for the plumbing I could always swap the sides of the bathroom that the vanity and the tub are on.



Thanks again!

 

[Tuttles Revenge]

The toilet and the tub are the only fixtures that need to be in the floor using standard fixtures. So placing the ejector closer to those is optimal. I often place my ejectors under a clothes dryer so it doesn't take up any foot print ( I have basins custom made out of Large Diameter sewer pipe and no pipe exits the lid ) But the laundry can travel through the wall and over to a point closer to the pump to avoid trenching just as you have in your second drawing.

To answer your question about whether a vent from an ejector can tie into the existing vents.. its No and Yes. In the UPC the code says it should go up independantely, but if it can't then it can tie into the other venting.

 

[HereInOhio]

The toilet and the tub are the only fixtures that need to be in the floor using standard fixtures. So placing the ejector closer to those is optimal. I often place my ejectors under a clothes dryer so it doesn't take up any foot print ( I have basins custom made out of Large Diameter sewer pipe and no pipe exits the lid ) But the laundry can travel through the wall and over to a point closer to the pump to avoid trenching just as you have in your second drawing.

To answer your question about whether a vent from an ejector can tie into the existing vents.. its No and Yes. In the UPC the code says it should go up independently, but if it can't then it can tie into the other venting.

That is a darn good idea to have the ejector pump under the dryer! In this case I will have a "closet" to hide where all of the plumbing ties into the main drain. I already have the ejector pump/basin. For this case I will just install the basin in the same closet with the rest of the plumbing for simplicity.

I'm under IPC, probably important for my questions below. I do not have an easy way to get to the roof so it looks like I'm going to tie into the rest of the venting.

Hopefully I can clearly explain what I am trying to figure out. To me it seems like the easiest way would be to run the 3" pipe from the basin up to the toilet. Along the way I will have a "wye" or "san tee" with 2" coming off to go to the bathtub. Would you continue that 2" pipe another 6" or so past the bathtub to the wall and go up into the wall to catch the rest of the fixtures (vanity, utility tub and washing machine)?

I thought you can only have the bathroom group wet vented together so I'm not sure if tying in the utility sink and the washing machine breaks that rule. If so my thoughts go all over the place from there (eg how many vents do I need, what separate pipes do I need to tie into the drain, what order does the stuff need to tie in and I could go on and on). I figured it would be easier for everyone just to ask the way you would run it and just do that vs. asking 100 separate questions to ultimately get to the same thing.

As always I appreciate your help! These projects are making me really appreciate what plumbers have to know. Just like everything we tend to just see the actual work and not everything that goes into it behind the scenes. Makes it a lot easier to open up the pocketbook knowing this.