Advice on adding a sink and laundry drain to a main stack.

[Raymond4646]

This is in a 1 story home. Sink and laundry drain will be in the basement with concrete floor containing in ground sewage pipe that connects to a main stack feeding upstairs bathroom, kitchen and shower with a roof vent.

Main stack has a connection already for a deep laundry utility sink that is fed by the washing machine via flexible hose.

I’d like to extend a branch 14ft away with a sink first, then the laundry drain at the far left of the branch that then connects to the main stack.

After reading through some of the forum posts I haven’t found any specific code compliant setup for what I’m looking to accomplish.

Thank you.

 

[Reach4]

You could put the sink to the right of the standpipe. Not to scale!

 

[Sponsor]

 

[Raymond4646]

View attachment 106172
You could put the sink to the right of the standpipe. Not to scale!

That’s a great diagram. Much better than my scribble lol. So from the top right side of the ptrap where the water exits, I must maintain a height of no less than 30 inches bringing my laundry supply drain box up to 45 inches from the floor is that correct?

 

[Reach4]

Max 42 above the bottom of the trap arm for IPC. That could put the top of the standpipe well more than 45 inches above the floor.

 

[Raymond4646]

Max 42 above the bottom of the trap arm for IPC. That could put the top of the standpipe well more than 45 inches above the floor.

But minimum is 30? I can’t go any lower correct?
Reason why I’m asking is I have a double stack washer dryer and wanted to use “the dryer box” for the dryer vent that exits about from 40-44 inches off the floor.

 

[Reach4]

But minimum is 30? I can’t go any lower correct?

There is a way to have two traps. I think for that, you may be able to use vertical wet venting... The standpipe 2-inch trap would be near the floor, and the standpipe would extend 18 inches or more above the bottom of that trap arm.

The trap for the laundry sink 1.5 inch trap would be a little higher (it has to fit under the sink). It could be a slip joint trap for easier alignment.


Above the two santees would be the AAV.

Could 2 inch carry the combined drainage, or would you need to up that to 3 inch? I don't know. See https://terrylove.com/forums/index.php?threads/3-drainpipe-required.87919/ #11.

At the end of that 14 ft run, what size pipe are you draining into?


The 802.4.3.1 method allows 2 inch to carry both for sure.

 

[Raymond4646]

There is a way to have two traps. I think for that, you may be able to use vertical wet venting... The standpipe 2-inch trap would be near the floor, and the standpipe would extend 18 inches or more above the bottom of that trap arm.

The trap for the laundry sink 1.5 inch trap would be a little higher (it has to fit under the sink). It could be a slip joint trap for easier alignment.

Could 2 inch carry the combined drainage, or would you need to up that to 3 inch? I don't know. See https://terrylove.com/forums/index.php?threads/3-drainpipe-required.87919/

Above the two santees would be the AAV.

For simplicity, I’m going with your first suggestion.
I wont use the dryer vent box. Im framing 2x6 walls so I can adjust where I install the dryer vent box. thank you very much for your assistance.

 

[Raymond4646]

There is a way to have two traps. I think for that, you may be able to use vertical wet venting... The standpipe 2-inch trap would be near the floor, and the standpipe would extend 18 inches or more above the bottom of that trap arm.

The trap for the laundry sink 1.5 inch trap would be a little higher (it has to fit under the sink). It could be a slip joint trap for easier alignment.


Above the two santees would be the AAV.

Could 2 inch carry the combined drainage, or would you need to up that to 3 inch? I don't know. See https://terrylove.com/forums/index.php?threads/3-drainpipe-required.87919/ #11.

At the end of that 14 ft run, what size pipe are you draining into?


The 802.4.3.1 method allows 2 inch to carry both for sure.

It’s a 4 inch main stack. Question, rather than 1.5 for the sink I could use 2 inch to keep it uniform correct?

 

[Reach4]

It’s a 4 inch main stack. Question, rather than 1.5 for the sink I could use 2 inch to keep it uniform correct?

I think yes.

Is that so you don't have to buy 10 ft of 1.5 inch pipe for a short run?

Maybe have a 1.5 inch slip joint trap from the tailpiece (https://www.homedepot.com/p/Oatey-1-1-2-in-White-Plastic-Sink-Drain-P-Trap-HDC9704B/316622155), to a "2 inch trap adapter" (such as https://www.homedepot.com/p/Charlot...male-Trap-Adapter-PVC-00104W-1000HD/205801116 that is cemented to a piece of 2 inch pipe into a 2x2x2 santee in the standpipe.

Charlotte Pipe 2 in. DWV PVC Sanitary Tee PVC004001000HD - The Home Depot

PVC fittings are for drain, waste and vent purposes. They are used in gravity-fed waste elimination systems and are for Non-Pressure systems. To be installed with solvent cementing, threading, flanging,

www.homedepot.com

 

[Raymond4646]

I think yes.

Is that so you don't have to buy 10 ft of 1.5 inch pipe for a short run?

Maybe have a 1.5 inch slip joint trap from the tailpiece (https://www.homedepot.com/p/Oatey-1-1-2-in-White-Plastic-Sink-Drain-P-Trap-HDC9704B/316622155), to a "2 inch trap adapter" (such as https://www.homedepot.com/p/Charlot...male-Trap-Adapter-PVC-00104W-1000HD/205801116 that is cemented to a piece of 2 inch pipe into a 2x2x2 santee in the standpipe.

Charlotte Pipe 2 in. DWV PVC Sanitary Tee PVC004001000HD - The Home Depot

PVC fittings are for drain, waste and vent purposes. They are used in gravity-fed waste elimination systems and are for Non-Pressure systems. To be installed with solvent cementing, threading, flanging,

www.homedepot.com

Yes exactly what I was going to do! That adaptor through the wall connecting to the 2” behind the wall.

All exposed piping inside the sink vanity will be 1.5.

I really appreciate the assistance! Thank you sir!