[jonhayden]

Hi,

I'm going to finish my basement in Colorado and need to move the bathroom rough-in. To start with, the sump pump in the original builder plan doesn't even exist in the builder plans location so that space is free to use. However, because of where they put the water heater, the hallway would be too narrow to use with the existing rough-in. So I'm proposing the following...see image. My question is, will code allow me to do this? Are angles okay? extending the distance okay? pipe size okay? Also, there is no venting anywhere in the rough-in. I've looked up down, sideways, and there is nothing. I asked the builder and he said his plumber said it's okay to use an Air Admittance Valve so I'm hoping that's okay too.

Now, figuring out how to bust up the concrete is another topic all together

Thanks,
Jon

 

[jonhayden]

Not sure if this helps, but my town uses:

The International Plumbing Code, 2006 Edition

 

[tylernt]

Assuming your local jurisdiction has no local amendments, from what I can tell AAVs do appear to be permitted under the 2006 IPC if there is at least one "real" vent through the roof somewhere else in the house.

However, AAVs have to be accessible for servicing and be able to "breathe" air freely, so you can't bury it in a wall. Under the sink would be the logical place for it. The AAV has to be within a certain distance of the traps it serves, so you may need to run the trap arms from the shower and toilet straight to the sink for the AAV, before turning to enter the main drain line. So instead of that branching Y configuration in your pic, you may need more of a T layout with the sink in the middle. I believe you'll also need a 3" AAV to match the largest drain in the system.

 

[jonhayden]

Thanks for your reply tylernt! My home has 2 vents that I can see so I should be okay there. And I was definitely planning on making the AAV accessible. I was even thinking about purchasing something like this recess box:

When you mention a T layout, do you mean something like this?

Thanks again,
Jon

 

[tylernt]

I was even thinking about purchasing something like this recess box:

Say, that's nice, gives you more flexibility on where to put it.

When you mention a T layout, do you mean something like this?

Where will you put the AAV?

 

[jonhayden]

Where will you put the AAV?

I was thinking in the wall that's between the shower and sink.

 

[Beepster]

You say your home has two vents... are any of these accessible from the basement? I believe, if at all possible, you should try and vent your basement bathroom out through the roof. The AAV is just a last resort when it is not possible to properly vent.

B

 

[jonhayden]

You say your home has two vents... are any of these accessible from the basement? I believe, if at all possible, you should try and vent your basement bathroom out through the roof. The AAV is just a last resort when it is not possible to properly vent.

B

They're on the complete opposite side of the basement, which is why I was going the AAV route. Thanks

 

[tylernt]

I was thinking in the wall that's between the shower and sink.

Based on this thread:

http://www.diychatroom.com/f7/distance-toilet-vent-146308/

it looks like that AAV location and your T layout will work. Of course use sweep fittings, not 90° corners.

Shower is 2 DFU, lav is 1 DFU, 2" pipe supports 6 DFU on a horizontal branch, so you're good size-wise.

 

[jonhayden]

Just to confirm. Does this look right? And I'm curious about the type of pipe connection to use between the 3" and 2" pipes. By sweep fitting, do you mean a Y? And is a T okay where the AAV pipe meets the sink/shower pipe? Thanks

 

[tylernt]

Yeah, the 45° Y fittings are the least likely to clog.

As for the 2" meeting the 3", you may be able to find a 3x3x2 Y like the one shown below, but it's just as effective to come off a 3x3x3 Y with a 3-2 reducer coupling, so don't drive all over town looking for the 3x3x2.

As far as I know, vents can use hard 90° tees though.

 

[jonhayden]

Thanks for your help. Much appreciated.

Jon

 

[jonhayden]

Final solution. Need to see if a cleanout is required, but I think this works good for me.

 

[tylernt]

I found this that mentions clean outs:

www.finehomebuilding.com/PDF/Free/021126070.pdf