Vent locations on new build

[Wayner123]

Hello all,

I have been reading a good deal on here and I thank each of you who have contributed over the years to help guys like me. I have attached my floor plan, and I am stuck on where to put the vent(s) for the bathrooms. I want to keep the vents to a minimum as this is a metal roof and I don't want to have that many pipes sticking out of the roof.

Can you please take a look at my plan and let me know where you would put the vent(s)? I can move things around a good bit at this stage (floor plan design), but this will be a concrete slab, and I want to make sure it's right now before anything goes vertical.

Also, right now the connections are drawn in as tee's, but I will use the proper swing fittings and wye's when actually laying it out. Any help is greatly appreciated.

 

[John Gayewski]

Hello all,

I have been reading a good deal on here and I thank each of you who have contributed over the years to help guys like me. I have attached my floor plan, and I am stuck on where to put the vent(s) for the bathrooms. I want to keep the vents to a minimum as this is a metal roof and I don't want to have that many pipes sticking out of the roof.

Can you please take a look at my plan and let me know where you would put the vent(s)? I can move things around a good bit at this stage (floor plan design), but this will be a concrete slab, and I want to make sure it's right now before anything goes vertical.

Also, right now the connections are drawn in as tee's, but I will use the proper swing fittings and wye's when actually laying it out. Any help is greatly appreciated.

Every trap needs a vent. Your sinks (lavs) need vents. You can't plumb a whole house with 0 vents through the roof. Just run all of the vents into the attic/roof rafter space and connect them. An aav here or there is fine, but they don't keep the air pressure equalized which needs to be done to keep things flowing at speed. You can penetrate anywhere your heart desires, but closer to the highest point on the roof is better. A metal roof uses a boot which is screwed and caulked to the metal surface. They are fine and work fine for many many many years if installed properly.

 

[Sponsor]

 

[Wayner123]

Every trap needs a vent. Your sinks (lavs) need vents. You can't plumb a whole house with 0 vents through the roof. Just run all of the vents into the attic/roof rafter space and connect them. An aav here or there is fine, but they don't keep the air pressure equalized which needs to be done to keep things flowing at speed. You can penetrate anywhere your heart desires, but closer to the highest point on the roof is better. A metal roof uses a boot which is screwed and caulked to the metal surface. They are fine and work fine for many many many years if installed properly.

Thank you for your advice. I know the plan only shows 2 aav's, but I know (thanks to this forum) that I need more venting, and per code I have to have at least 1 stack that runs through the roof.

However, I don't want to run 7 pipes (3 in guest and 4 in master bathroom) into the "attic" area. So I was looking for an idea of how to use 1 vent per bathroom.

Hopefully that helps to clarify what I need advice on.

 

[Reach4]

Your lower right bathroom has two fixtures entering before the vented lav drain. The lav is doing the wet venting. You want to run the toilet to join downstream of the wet vent entering.

 

[Wayner123]

Thanks to all so far. I have re-worked the master bath area, and I hope this configuration is legal. This allows for one vent for the bathroom.

 

[John Gayewski]

Thanks to all so far. I have re-worked the master bath area, and I hope this configuration is legal. This allows for one vent for the bathroom.

From the lowest point to the highest point in this picture go like this. Wye for the toilet, wye for the lav, wye for the shower. Then they can share the vent. Put these wyes on the main don't wye off of each other.

Each wye branch needs to stay horizontal (with slope) and be within the trap arm lengths required, until they turn up for the fixture. The longer underground run for the lav doesn't need to be within a certain length. Just the shower and toilet.

 

[John Gayewski]

The larger problem you have with horizontally wet venting this is your first bathroom. It needs to have nothing but that bathroom draining into it. Meaning a bathroom group can only have one set of bathroom fixtures draining/venting together.

 

[Jeff H Young]

The larger problem you have with horizontally wet venting this is your first bathroom. It needs to have nothing but that bathroom draining into it. Meaning a bathroom group can only have one set of bathroom fixtures draining/venting together.

I thought IPC code allows 2 bathroom groups to be wet vented?

 

[Reach4]

His two bathrooms are far apart, and there is kitchen and laundry in between.

 

[Wayner123]

Thank you guys for all your help.

From the lowest point to the highest point in this picture go like this. Wye for the toilet, wye for the lav, wye for the shower. Then they can share the vent. Put these wyes on the main don't wye off of each other.

Each wye branch needs to stay horizontal (with slope) and be within the trap arm lengths required, until they turn up for the fixture. The longer underground run for the lav doesn't need to be within a certain length. Just the shower and toilet.

I have attached a drawing that I believe shows what you are recommending?

His two bathrooms are far apart, and there is kitchen and laundry in between.

Are you saying I can wet vent then, or that I can't because of the down stream connections?

 

[James Henry]

Thanks to all so far. I have re-worked the master bath area, and I hope this configuration is legal. This allows for one vent for the bathroom.

Post your whole house floor plan as a JPEG. So people can mark it up.

 

[Wayner123]

Post your whole house floor plan as a JPEG. So people can mark it up.

 

[Reach4]

What is going on in your laundry room? Two traps, each with an AAV? Two traps sharing an AAV with the horizontal joining 6 inches above the higher flood level?

With separate traps, once the laundry standpipe waste joins the laundry sink waste, the pipe should be 3 inches.
There is an alternative where the laundry sink waste joins the standpipe before the trap. If interested, there is more info on that topic. With separate traps, as you have planned, changing a bit of 2 inch in your plan to 3 inch is not a big deal.

https://wabo.memberclicks.net/assets/pdfs/Plumbing_Venting_Brochure_2018.pdf does not address the standpipe/laundry thing, but may be of interest.

 

[wwhitney]

With separate traps, once the laundry standpipe waste joins the laundry sink waste, the pipe should be 3 inches.

That requirement appears in IPC 406.2: "The fixture drain for the standpipe serving an automatic clothes washer shall connect to a 3-inch (76 mm) or larger diameter fixture branch or stack." However, the IRC's plumbing section (the P chapters) does not have anything equivalent to my knowledge.

So to determine if the requirement applies in a single family dwelling in a jurisdiction that has adopted both the IPC and the IRC, you need to check the scoping section in Chapter 1 of the jurisdiction's version of the IPC. If the jurisdiction has adopted the full IPC including the exemption for single family dwellings, and has adopted the IRC's plumbing sections, then IPC 406.2 doesn't apply. If, however, the jurisdiction has not adopted the IRC's plumbing sections, and has amended away the exemption in the IPC for single family dwellings, then IPC 406.2 would apply if not also amended.

A brief perusal of up.codes indicates that Florida falls in the former category.

Cheers, Wayne

 

[wwhitney]

Are you saying I can wet vent then, or that I can't because of the down stream connections?

Per your drawing in post #12, what you need to do to wet vent the bathroom at the top of the page is to keep its branch drain separate from the building drain. I.e. instead of running each fixture directly to the 4" building drain, start a parallel branch with the lavatory drain hitting the WC drain, and then the combined drain hitting the tub, and finally the branch drain can join the building drain.

Cheers, Wayne

 

[Wayner123]

What is going on in your laundry room? Two traps, each with an AAV? Two traps sharing an AAV with the horizontal joining 6 inches above the higher flood level?

I took out the utility sink for now. If I need to add it back, I will simply take it out the side wall and into the landscaping.

Per your drawing in post #12, what you need to do to wet vent the bathroom at the top of the page is to keep its branch drain separate from the building drain. I.e. instead of running each fixture directly to the 4" building drain, start a parallel branch with the lavatory drain hitting the WC drain, and then the combined drain hitting the tub, and finally the branch drain can join the building drain.

Cheers, Wayne

I appreciate your explanation. In the configuration you explain in post #15, will it go 2" vent > 2" line > 2"x4" reducer > 4" wye (connecting the 4" WC line) > 4" line > 2"x4" 90 sweep (to connect the shower) > 4" line and connect back to main drain? If so, I have attached a drawing which shows this.

My main goal is to limit the amount of "through the roof" vents and attic plumbing I will need. So if it makes more sense to redo all of what I have drawn, I am cool with that too, as long as it helps to reduce roof vents and attic plumbing. Thanks again for all ya'lls help.

 

[wwhitney]

I appreciate your explanation. In the configuration you explain in post #15, will it go 2" vent > 2" line > 2"x4" reducer > 4" wye (connecting the 4" WC line) > 4" line > 2"x4" 90 sweep (to connect the shower) > 4" line and connect back to main drain? If so, I have attached a drawing which shows this.

Yes, that's fine, with the provisos:

Everything listed above as 4" could be 3".
2" x 4" 90 sweep is usually called a 4x4x2 combo.
With a 2" tub trap arm, you'll need a 2" tub trap, which is fine. You can adapt from the 1.5" waste and overflow on the inlet side of the trap. If you use any tubular fittings, they need to be accessible.

Cheers, Wayne

 

[James Henry]

Your struggling.

https://www.ipscorp.com/pdf/studor/Studor_Technical_Manual.pdf

 

[Wayner123]

With my current layout in post #16, which sections would be considered trap arm length?

 

[John Gayewski]

With my current layout in post #16, which sections would be considered trap arm length?

From the fixture to the main.

I'm not sure on ipc. But having the toilet trap arm upstream if the bathtub trap arm isn't allowed in upc. Which I think is actually one of the better requirement differences. You might want to think about switching these.