Installing a sink in garage - best drain solution?

House Repair Talk

Help Support House Repair Talk:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Msupsic

Marc S.
Joined
Jun 24, 2010
Messages
80
Reaction score
1
I'm making a small winery in my garage, and will need to wash dirty dishes/fill and clean the wine tanks regularly. There is currently a cold water spigot in the garage. I was hoping to rig a wash basin up to this so I can use the water supply with an industrial stainless sink.

My main concern is draining the waste water. I would be mostly draining dead yeast, old wine, soap and water and a mild bleach solution used for cleaning tanks.

I might have to drill through the cinder block foundation, into the basement and run drain pipe to either the clothes wash basin, or over twenty feet away to the main waste stack.

What are my options and what, if any laws are there regarding waste water? Can I use PEX or flexible tubing for the drain tube, and just let the waste dump into the sinks down in the basement?

I want to make as few alterations to the garage as possible, in case we ever have to sell the house. It would be good if I can yank the system and leave as little a mess as possible for future owners.

Thanks!
 
I was thinking of the same thing but wasn't sure how the draining and venting would work. I have a water spigot in the garage as well. I would like a wash basin or sink in my garage for rinsing parts and washing my greasy dirty hands without going inside. Look forward to hearing some responses on this. Good Luck!
 
Lets throw in one big potential problem before we even consider the rest...

Is your garage heated? :eek:
 
I've blown in insulation and have a standalone heater in the space. Even without the heater, It doesn't get below 60°F in there... why do you ask?
 
Freezing concerns...
Your drain from the sink will need a vent through the roof or, be tied into an existing vent (check your local code), and will need a 1 1/2" or 2" (check your local code) drain pipe pitched downward at 1/4" per foot to where ever it ties into a drain at.
 
The closest drain pipe is for the sink in the basement. There is a dual wash basin that drains into the sewer main.

I've attached two diagrams. Would it be acceptable to tie into the drain pipe of the basement sink as shown? The basement sink, in turn, drains off into the main waste drain for the house.

sink.jpg

sink2.jpg
 
Last edited:
I'd be worried that he garage sink would suck the P-trap dry on the basement sink and if you tied in above the P-trap, it would backup into the basement sink.
 
Don't they make some sort of valve that you can install so that this doesn't happen?

Would it be easier just to dump the drain pipe into the open wash basin as a temporary solution? I mean, I'll have to remove it when we sell the house anyway.
 
Last edited:
You would need to vent the sinks properly to protect the trap seal.

An over simplified definition of venting is that it allows air to enter the drain behind the slug of water doing down the drain to prevent the water from siphoning out of the trap.
 
You're right about the venting, and I think I've got the solution to this layout. It's called a Studor Valve and does exactly what you described. It opens when there is a vacuum in the pipe, and closes to prevent fumes, etc. from leaking out of the valve.

See attached diagram.

Thanks for all of your help, everyone!

sink_studor.jpg
 
A studor vent may or, may not be allowed under your local plumbing code.
I would check if the local code allow the usage of a studor or, AAV.
They are not the best way to vent and a poor replacement for a through the roof vent.

In your diagram the studor is improperly placed and needs to be changed. Check your local code.
 
Thanks for the heads-up. I bought a Studor kit at Lowes last night, and the installation instructions have it coming right off of the s-trap. In fact, the kit comes with its own s-trap and shows a picture of the studor vent in-line, right after the trap.

Where is it "supposed" to go?

By the way, this is not going to be a permanent installation. I plan on making the whole drain system removable, in case we ever move. I just need a sanitary, enclosed method of draining off my excess wine fluids.
 
S-traps are illegal under every code I know of.
The Studor has to extend above the flood rim of the sink check your local code for distances. The way it is lied into the lower drain also prevents a venting problem. Wet venting between floors is not permitted.
 
Pardon my terminology, I'm sure it's not an S-trap if they are illegal. The kit includes your standard, very legal trap, whichever letter of the alphabet that may be.

I'll be sure to place the studor above the flood line if I do use it. some PVC piping will easily extend the tube above the height of the sink.

As for the wet venting issue, I think there are other systems in the house which already do this. The house was built in the forties, was this allowed back then?
 
No wet venting between floors wasn't legal then either.
This old picture shows proper venting of every fixture...

sizing-4.jpg
 
Back
Top