Garage Sink Drain/Vent Question

[Jarrd]

I am wanting to put a sink in my unheated garage. I only have one pipe I can connect to for the sink drain. This is all inside the house up against the garage foundation to avoid freezing in the winter. I have added a picture of what I am thinking of doing but not sure if it will work. The blue it what I am thinking of adding for the sink drain. Everything else is existing. I tried searching quite a bit but can't find anything quite like my situation if this will work?

I'm trying to work with what is existing to make it work. If it doesn't work that's fine but just looking to get some feedback if it will be up to code or any other suggestions on how to make it work with what I have?

Thanks in advance for the help.

 

[WorthFlorida]

Having a drain in a garage is unusual since gasoline fumes are heavier than air, the gasoline fumes can enter the drain and be troublesome should the trap dry out or spilled gasoline drains into it. The main question is where does this floor drain into? Your septic system, city sewer or a sump pump. Are you sure it has a trap? Does the floor drain trap freeze in the winter? The pipe for venting, is it for venting only to the roof? Anything above drain into it? If yes an AAV can be used. If the clean out already exist then it most likely drains into the septic system.
I'm not a plumber but it looks like tapping into the vertical vent pipe, you'll be creating a wet vent for the floor drain. Some areas do not allow certain wet venting. Hopeful someone else will answer that question.

 

[Sponsor]

 

[Jarrd]

Having a drain in a garage is unusual since gasoline fumes are heavier than air, the gasoline fumes can enter the drain and be troublesome should the trap dry out or spilled gasoline drains into it. The main question is where does this floor drain into? Your septic system, city sewer or a sump pump. Are you sure it has a trap? Does the floor drain trap freeze in the winter? The pipe for venting, is it for venting only to the roof? Anything above drain into it? If yes an AAV can be used. If the clean out already exist then it most likely drains into the septic system.
I'm not a plumber but it looks like tapping into the vertical vent pipe, you'll be creating a wet vent for the floor drain. Some areas do not allow certain wet venting. Hopeful someone else will answer that question.

Thanks for the reply.

I’m not exactly sure where the garage drains to. It’s pretty common to put a drain in the garage on new homes here in MN. It was put it when they built the house. They ran it from the garage into the house and put a p-trap there so it doesn’t freeze in the winter. Then it runs to a San tee and into the floor. I’m pretty sure the vent runs straight to the roof. I don’t see anything else draining into it.

I know wet vents are allowed here, the toilets on the upper lever are wet vented. code says fixtures must be on the same floor level. I just don’t know if setting it up the way I showed above would work or be fully to code.

 

[Jeff H Young]

looks good with exception you need 2 inch santee at bottom for floor drain and 2x1 1/2x 2 santee above and a 2 x1 1/2 x1 1/2 santee or combi for sink. So the vertical will be all 2 inch and horizontal to the sink reducing to 1 1/2 when it becomes a trap arm

 

[Jarrd]

looks good with exception you need 2 inch santee at bottom for floor drain and 2x1 1/2x 2 santee above and a 2 x1 1/2 x1 1/2 santee or combi for sink. So the vertical will be all 2 inch and horizontal to the sink reducing to 1 1/2 when it becomes a trap arm

Ok. Perfect. That makes sense. Thanks for the assistance!

In case anyone is wondering, I’m using a hot/cold freeze proof sillcock the “faucet” to prevent the water lines from freezing since the garage is unheated.