Horizontal Venting Layout Check, Venting, and Garage Floor Drain ?

[MikeFromMO]

Updated design in latest post at the bottom.


First post and have a few questions.

We’re putting up a 40x60 foot building on our farm we bought. We’re going to put a small apartment in it. Basically 4” concrete slab 40x60 feet with slab on top.

Working on doing the rough plumbing now.

Here’s some photos to give a better idea of the project.

We’re on IRC 2015 here for this project.
Question 1.

Is it possible to use a double 3” x 2” wye where 3” is the center opening on both sides with 2” feeding into it and achieve a horizontal wet vent? Toilet would feed into the 3” and run straight across, 2” from lav (vented to roof), and 2” from shower into the other (not vented to roof). From there 3” line to a wye in the 3” main line.

This would by far be the easiest setup routing wise.

Question 2

If the double wye won’t work. Would the below setup meet the horizontal wet vent requirement. (Obviously not sloped correctly just mocked up.)

Question 3

The apartment where all the plumbing is 14’ wide from inside to the garage portion of the build.
Would it be possible to vent everything (bathroom, kitchen sink, washing machine) out one 2” stack on the outer edge of the building by the shower? What about the laundry sink in the garage portion or would that be too far on a 2” vent line? ( it would be about 13.5 to 14 feet from the vertical vent coming out of the Sanitary tee to the vertical vent pipe location near the wall by the shower.

There’s a loft above and I’d like to not have a pipe running through the middle.

Question 4.

As an afterthought (after we poured foundation) we talked about putting in some floor drains to catch melted snow and water off of vehicles. The main drain line is 3”

I was going to put a clean out down on the very end. The 90 degree elbow represents the clean out and the two wyes are where we would put the drains.

Is there any way to do this without running vent lines?

Thanks in advance!

Mike

 

[James Henry]

I use the same code. Mark on the floor plan where the drain exits the building and if their are multiple exits. I can't make heads or tails between the floor drain picture and the floor drain sketch.

First off. Question 1. The answer is No. " there can only be one fixture upstream of a horizontal wet vented system". when you connect the shower to the lav you now have two fixtures upstream of the wet vent. the shower and the toilet. You can connect the lav downstream of the toilet and then the shower downstream of the lav. That is 2015 IPC acceptable.

Question 2. would be a No. You can connect a wet vent vertically off the drain or horizontally but you cannot offset from vertical to horizontal on any vent lower than 6" above the flood level rim of the fixture.

Question 3. You need to tie all the vents together and pop a 3" vent out the roof. 14' is nothing.

 

[Sponsor]

 

[MikeFromMO]

I use the same code. Mark on the floor plan where the drain exits the building and if their are multiple exits. I can't make heads or tails between the floor drain picture and the floor drain sketch.

First off. Question 1. The answer is No. " there can only be one fixture upstream of a horizontal wet vented system". when you connect the shower to the lav you now have two fixtures upstream of the wet vent. the shower and the toilet. You can connect the lav downstream of the toilet and then the shower downstream of the lav. That is 2015 IPC acceptable.

Question 2. would be a No. You can connect a wet vent vertically off the drain or horizontally but you cannot offset from vertical to horizontal on any vent lower than 6" above the flood level rim of the fixture.

Question 3. You need to tie all the vents together and pop a 3" vent out the roof. 14' is nothing.

On question 2 the lav is coming in at less than a 45 degree angle not vertically to the other line. May just be the perspective. Would that be acceptable?

 

[James Henry]

On question 2 the lav is coming in at less than a 45 degree angle not vertically to the other line. May just be the perspective. Would that be acceptable?

It will not pass like that. before any building drainage is designed the general location of where the building sewer will connect must be known. if you can point that out for me I can give you you some basic ideas.

 

[James Henry]

As far as Question 4. goes. Theirs a difference between a Garage floor drain and an Emergency floor drain. an Emergency floor drain is for rooms that carry water lines and may leak or overflow and a Garage floor drain is for water that you bring in... I personally would install a trench drain in the garage but I would not hook it up to the house drain because you would have to have p-traps and trap primers installed and you would be sweeping dirt down it and it would just foul the house drain up. You should do some research and decide whats best for you. And just because a floor drain is open to the air it still needs a way to vent or it wont drain. (Been there, Done that).

 

[James Henry]

It's Saturday, I got nothing better to do.

 

[MikeFromMO]

I think I’m over complicating this whole thing.

I’m going to need a 3” vent line through the roof anyways (thank you for pointing that out.). I forgot it had to be the same total size as the main drain in total vents.

If this would work that is....

Toilet dumps into 3” san t with 2” side entry. 3” Vent runs out of top of San T.

Lavatory drains into this 3” vent line via a 3”x3”x 2” San tee.

3” vent continues running out of top plate and all (2”) vents from kitchen sink, washing machine, and garage laundry sink tie into this 3” line.
3” line continues and penetrates roof.

 

[MikeFromMO]

This is the new layout that I hope will work better. Hopefully this checks off all the boxes.

The double cleanout on the 3” would be a double sanitary tee.

The vents from the laundry sink, bathroom Lav, kitchen sink, and washing machine, will tie into the 3” line that runs from the Toilet up through the roof.

 

[James Henry]

You can't vertically wet vent a bathroom with a kitchen sink. That will work with just the lav attached but you have to run the sink drain somewhere else off the line.

 

[MikeFromMO]

You can't vertically wet vent a bathroom with a kitchen sink. That will work with just the lav attached but you have to run the sink drain somewhere else off the line.

To clarify the kitchen sink would have a can’t coming out the top of its San tee’s to tie back into the 3” line that comes up from the double sanitary tee.

like I said the wet venting was just over complicating things for no reason I think.

I guess the question is can the kitchen sink go into the 3” drain line that runs down to the toilet like that or does it have to have its own independent 2” line running down to a 90 long sweep and then into a wye on the 3” main drain line.

 

[James Henry]

You didn't leave yourself much of an opening with your layout because of the sink and toilet being back to back. I wouldn't tie the kitchen drain into the toilet drain because theirs to much potential for a clog at the main drain y-fitting, especially with a garbage disposal. You may be able to pull off what I drew out on the photo but to me I can only see 2-D from a photo.