Adding a utility sink outside...

[xa1200]

We’ve always wanted to add an utility sink in the backyard and now is a perfect time to do it during social distancing. Excuse the mess.. we don’t explore the deep end often. Previous owner left us a lot of surprises.

Is it possible to tap into the existing shower drain by:

sink > p-trap > pipe through the wall > this pipe will have a drop of 1/4 > 90 degrees into 1/8 bend and wye to the horizontal line?

 

[MACPLUMB]

You need a Tee after the P-Trap with a riser with a AAV to vent the drain

 

[Sponsor]

 

[xa1200]

You need a Tee after the P-Trap with a riser with a AAV to vent the drain

Thank you!

Is there a minimum height for the riser? As you can tell, I don’t have much vertical space there.. but I’m assuming you mean prior to penetrating the wall?

 

[Reach4]

Is there a minimum height for the riser?

Usually 4 inches. You need space for the AAV, and space to unscrew the AAV.

https://s3.amazonaws.com/s3.supplyhouse.com/product_files/Oatey-39017-User-Guide.pdf

 

[xa1200]

Usually 4 inches. You need space for the AAV, and space to unscrew the AAV.

https://s3.amazonaws.com/s3.supplyhouse.com/product_files/Oatey-39017-User-Guide.pdf

Thank you! Will be a fun project!

Naturally curious.. would there be an issue draining into the 4" toilet drain line via the same method?

 

[Reach4]

Naturally curious.. would there be an issue draining into the 4" toilet drain line via the same method?

Depends. Do you mean draining the sink upstream of the toilet, or downstream? If upstream, you could be interfering with a bathroom group wet vent.

 

[xa1200]

Depends. Do you mean draining the sink upstream of the toilet, or downstream? If upstream, you could be interfering with a bathroom group wet vent.

It would be downstream (after the toilet drain).

 

[Reach4]

I think you would be OK. I would try to wye in from higher.

 

[MACPLUMB]

42" is the correct answer for vent height, run up on the outside wall, tie in below like you want,
BUT use shielded metal coupling bands, all rubber are for outside foundation,

 

[xa1200]

Ok I've been researching about DWV a bit more.

1. Instead of making a physical penetration in the wall, can i route the pipe to go down the crawl space hole and enter the toilet drain pipe with a wye? The sink will be right next to this hole.


2. Does it appear that the toilet drain does not have a vent pipe? This section connects with the sink piping in the first post and all goes to the same "stack". I wonder if this was done incorrectly?

 

[xa1200]

Any takes?

 

[MACPLUMB]

Be aware that if you block off any part of the crawlspace access, you might have problems in the future when someone
needs to under to work and/or parts and materials down below !

 

[xa1200]

Be aware that if you block off any part of the crawlspace access, you might have problems in the future when someone
needs to under to work and/or parts and materials down below !

We plan on staying here a long time! But we can easily remove it without leaving any holes in the wall too! Plus I think a 1.5 inch pipe would not take up too much space.

Do you think my new plan would work? I was afraid of making too many turns with the wet vent.

 

[Reach4]

I suggest that you make a line drawing of the drain and vent piping as you think it goes.