Drain Pipe Height From Floor?

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HereInOhio

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I'm trying to figure out the typical height to install my horizontal drain pipes. One wall has a 2" washing machine standpipe drain going through it as well as a separate 1 1/2" utility sink drain that needs to go above it. I'm in Ohio so under IPC. Do you know if it specifies a min/max height?

The other wall is just a double lav that will lead into a drain in the floor. Here again I'm wondering what height to run the pipe horizontal at? This wall will also need a vent pipe running horizontally through it, which will include a shower head in the middle. I know the vent has to go above the flood level and would assume all the way at the top by the ceiling is a dangerous zone since someone could install crown later on. With the shower head having to extend high on the wall it would be nice to have it above so the supply pipe to the shower head doesn't need to wrap around the vent but it would be pretty close to the ceiling. Any recommendations or advice would be appreciated.

Thanks
 
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Reach4

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I'm trying to figure out the typical height to install my horizontal drain pipes. One wall has a 2" washing machine standpipe drain going through it as well as a separate 1 1/2" utility sink drain that needs to go above it. I'm in Ohio so under IPC. Do you know if it specifies a min/max height?
IPC does not specify minimum and maximum above the floor, but does have a minimum and maximum for the standpipe.

IPC wants a laundry standpipe that combines with anything else go into a 3 inch or bigger pipe.

There is an exception that can let you have a standpipe and laundry tub right next to each other, with some limitations, and feed the combo into a 2 inch pipe. This picture shows an AAV, but of course you can use a real regular vent.
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he other wall is just a double lav that will lead into a drain in the floor. Here again I'm wondering what height to run the pipe horizontal at? This wall will also need a vent pipe running horizontally through it, which will include a shower head in the middle. I know the vent has to go above the flood level and would assume all the way at the top by the ceiling is a dangerous zone since someone could install crown later on. With the shower head having to extend high on the wall it would be nice to have it above so the supply pipe to the shower head doesn't need to wrap around the vent but it would be pretty close to the ceiling. Any recommendations or advice would be appreciated.
I am confused by much of your description. Horizontal drain pipe for a lavatory might just be the trap arm. The other pipes might be vertical. I suggest illustrating what you are asking with a sketch.

Flood level for a shower is the rim of the shower base, not the height of the showerhead.
 
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HereInOhio

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IPC does not specify minimum and maximum above the floor, but does have a minimum and maximum for the standpipe.
Ok I was aware of the standpipe specs. The standpipe has around 5' to run horizontally from behind the washer to where it goes into the floor. Is there a height you would recommend running this 5' horizontal drain pipe? I would think a minimum of 8" high to avoid any trim nails for baseboards. Besides that is it better higher or is there a typical height you aim for?

There is an exception that can let you have a standpipe and laundry tub right next to each other, with some limitations, and feed the combo into a 2 inch pipe. This picture shows an AAV, but of course you can use a real regular vent.
This is interesting, I was going to run two drain pipes until now since I don't have the space to fit a 3" pipe in the wall. Is this frowned upon where I would be better off running two drain pipes or I'm fine running it this way? The washer and utility tub are right next to each other so the distance will be well under the 30".

I am confused by much of your description. Horizontal drain pipe for a lavatory might just be the trap arm. The other pipes might be vertical. I suggest illustrating what you are asking with a sketch.
I'm sorry I am aware I have a way of confusing people with how I explain things. I added a picture to hopefully help. When I say horizontal drain pipe I have sections of pipe running in the wall roughly 8' (in green). I'm trying to figure out how high I should put those off the floor? I understand it will be sloped so it will change slightly but a rough aim to. Based on your first statement that there's not a min/max do you have a recommendation?

Maybe I'm thinking about this too much but I don't know if it's best to have it at 18" which is what I was going to rough in the drain for the lav or if it's best to leave the 18" rough in but have the pipe drop down 6" or so before running horizontal around 12" off the ground? This is where I'm confused what would be best.

Flood level for a shower is the rim of the shower base, not the height of the showerhead.
I understand the flood level. I have a 2" vent running through the wall (Dark Blue) that has to be above the flood rim of the highest fixture, in this case the lav (purple). Based on my assumption it would probably be best not to completely hug the ceiling to avoid any crown trim nails going through. Since I have the shower head practically at the ceiling, the pipe that runs from the shower control valve to the head (teal) will have only 1/2" to wrap around the front or back of the 2" vent pipe. Is there any standard or recommended heights for vents that have to run horizontally through walls? If not are there any tricks when you need to get pipes around them?

Sorry if this still isn't clear.


Bathroom.GIF
 

John Gayewski

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Run thr horizontal drain about 12" from the floor. No tricks. Just run the vents toward the back of the stud pockets so your shower pipe can be in front.

1.5" vents are fine. When they combine maybe go to 2"
 

wwhitney

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The standpipe has around 5' to run horizontally from behind the washer to where it goes into the floor. Is there a height you would recommend running this 5' horizontal drain pipe? I would think a minimum of 8" high to avoid any trim nails for baseboards. Besides that is it better higher or is there a typical height you aim for?
Nothing typical, whatever height works for your situation.
This is interesting, I was going to run two drain pipes until now since I don't have the space to fit a 3" pipe in the wall. Is this frowned upon where I would be better off running two drain pipes or I'm fine running it this way? The washer and utility tub are right next to each other so the distance will be well under the 30".
Either way is fine.
I'm sorry I am aware I have a way of confusing people with how I explain things. I added a picture to hopefully help. When I say horizontal drain pipe I have sections of pipe running in the wall roughly 8' (in green). I'm trying to figure out how high I should put those off the floor? I understand it will be sloped so it will change slightly but a rough aim to. Based on your first statement that there's not a min/max do you have a recommendation?


Maybe I'm thinking about this too much but I don't know if it's best to have it at 18" which is what I was going to rough in the drain for the lav or if it's best to leave the 18" rough in but have the pipe drop down 6" or so before running horizontal around 12" off the ground? This is where I'm confused what would be best.
Either way is fine. I'm assuming the vertical green line is a drain that carries only the two lavs. Then if you put your horizontal pipe in the wall at the lav stub-out height (slightly different for each lav, due to the slope), you just need one vent takeoff in between them. That dry vents the left lav and wet vents the right lav. The left hand stub-out is a LT90, the right hand stub-out is a horizontal combo

Or if you run your horizontal wall pipe lower than your vent stub outs, you'll need a san-tee at each lav. So you'll have two dry vents, which you can combine as shown.

As John commented, your vent for the two lavs can be 1-1/2" either way, which will make routing it behind the shower riser easier than 2".

Cheers, Wayne
 

HereInOhio

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Nothing typical, whatever height works for your situation.

Either way is fine.

Either way is fine. I'm assuming the vertical green line is a drain that carries only the two lavs. Then if you put your horizontal pipe in the wall at the lav stub-out height (slightly different for each lav, due to the slope), you just need one vent takeoff in between them. That dry vents the left lav and wet vents the right lav. The left hand stub-out is a LT90, the right hand stub-out is a horizontal combo

Or if you run your horizontal wall pipe lower than your vent stub outs, you'll need a san-tee at each lav. So you'll have two dry vents, which you can combine as shown.

As John commented, your vent for the two lavs can be 1-1/2" either way, which will make routing it behind the shower riser easier than 2".

Cheers, Wayne

Yes, the green is the discharge and is wet venting the wc and shower so I believe I need a 2” vent for that portion limiting the space for the shower raiser to pass by.

Thanks for the response and fitting advice! I wasn’t aware you needed the LT and combo when stubbing out so I’m glad you said something.
 

wwhitney

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The IPC will let a 1-1/2" dry vent on the lav be used to wet vent a bathroom group. Any portion of the wet vent carrying 2-4 DFUs has to be 2".

So starting at the left hand sink, with the horizontal wall pipe at the lav stub out height, you could do the following order:

1-1/2" LT90 stub-out - 1-1/2" pipe - 1-1/2" upright combo for dry vent - 1-1/2" pipe - 2x1-1/2x1-1/2 horizontal combo for stub-out - 2" pipe - 2" quarter bend - 2" down into the slab.

Cheers, Wayne
 

HereInOhio

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The IPC will let a 1-1/2" dry vent on the lav be used to wet vent a bathroom group. Any portion of the wet vent carrying 2-4 DFUs has to be 2".

So starting at the left hand sink, with the horizontal wall pipe at the lav stub out height, you could do the following order:

1-1/2" LT90 stub-out - 1-1/2" pipe - 1-1/2" upright combo for dry vent - 1-1/2" pipe - 2x1-1/2x1-1/2 horizontal combo for stub-out - 2" pipe - 2" quarter bend - 2" down into the slab.

Cheers, Wayne
Thanks for the layout, makes perfect sense and will save me a bit of work!

I'm having a hard time finding the 2x1-1/2x1-1/2 horizontal combo. I'm sure a plumbing house would carry it but they all close before I get off work. I can find 2x1-1/2x1-1/2 san tee or I can use a 2x2x1 1/2 combo with a reducer bushing? Assuming the latter is preferred?

For venting everything:
The 2" vent drops down from the ceiling and will split off into the 3 vents for the basement, 2" for the ejection pump will go straight down to it, a 1 1/2" vent will go to each side (left to the bathroom group portion and right to the standpipe/utility sink).
1) Looking at the charts a 1 1/2" vent for the standpipe section is sufficient, correct?
2) Can I use an upside down 2" x 1 1/2" double san tee to connect all of these vents together or would I be better off with a 2" cross (non san tee) with reducer fittings?
 

wwhitney

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0) I was going to say that a 2 x 1-1/2 x 1-1/2 combo doesn't exist and to just use a 2 x 2 x 1-1/2 with a reducer bushing in the straight inlet. But I see it does exist. Either way is fine.

1) Yes

2) Either is fine, I'd choose the double san-tee or stacked san-tees.

Cheers, Wayne
 

HereInOhio

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Standpipe Vent.GIF


I am trying to keep the vent as close to the standpipe as I can but I have an obstacle to work around doing so. The distance from the standpipe to where it drains into the floor is just over 7'. If I can install it around 5' from the trap it would make the installation much easier and look nicer. How far from the trap am I permitted to install the vent?
 

wwhitney

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The pipe from the trap outlet to the vent (AAV in this case) is call the trap arm. The trap arm has to fall at 1/4" per foot minimum as usual, but its total fall is limited to one pipe diameter to prevent siphoning. The IPC has no further restrictions on trap arm length.

So for a 2" trap arm, if you get the slope exactly 1/4" per foot, your trap arm can be up to 8' long.

Cheers, Wayne
 
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