Can you check my DWV rough-in?

[mystryda]

Hi,

Can you check my DWV rough-in?

I've attached a sketch of the roughin with the non-obvious fittings labeled, along with the bathroom layout. To give a scale, the upstairs full bath on the right is 6.5'x6.5'.

The 3" branch that everything drains into will run in a soffit below the joists. I'm trying to keep everything else in the joist space. Exterior walls are along the bottom and left. The upstairs 3/4 bathroom on the left might not get put in, so the venting on the right needs to be sufficient on its own.

Two things I'm concerned about:
--Is the venting for the toilet sufficient/correct? I read something about needing extra venting when there's a fixture after the toilet.
--Does the upstairs stack empty into the downstairs stack (next to 1/2 bath) correctly? Something about the upstairs waste emptying into the stack below the downstairs waste--so do I need two stack in parralel past the downstairs toilet?

Thanks!

 

[Terry]

The wet vents for the shower or lav need to come in downstream of the toilets.
You have them upstream.

The lav can wet vent "over' the shower, not the other way around.

The waste for the upstairs can to come in "below" the toilet downstairs. The downstairs lav can wet vent over the toilet.

 

[Sponsor]

 

[mystryda]

Terry,

Thanks for the quick response.

Does this fix the problems you saw? Any other suggestions?

Cheers,

 

[Terry]

Yes,
That fixexs it.
Good job.

 

[hj]

You had it right the first time. The shower was NOT wet vented, and the lavatory had its own vent. The left hand toilet has a flat vent and NOTHING to flush it out, regardless of where it is attached. The right side is a better vent, but the old way was also adequate since the flat vent was being flushed by the lavatory. I cannot correlate your DWV drawing to the bathroom floor plans, but if the right had sink drain is close enough to the vertical riser, you do not need that "run around" for a vent. You may also not need the separate vent in your new drawing if the lavatory on the left is close enough to connect directly to the vertical riser. What kind of "side inlet fitting" are you using for the tub, because very few of them are drainage fittings approved for that location.

 

[Terry]

I was too quick last night.
The left lav and shower were fine the first time.
If you were to wet vent the lav, it would have been over the shower.
The trap arms on the lavs can be up to 42" long. It would get rid of some pipe and fittings you have.

 

[mystryda]

Take 3

So got rid of the big loop on the sinks (all waste arms less than 42"), and vented the left-most WC differently. I could only find a side inlet elbow in 3", so I switch to a med. sweep 90 plus san T fon the vent. Better?

I noticed that the layout has an error, which may cause some confusion. The toilet and sink in the full bath are flipped; I've attached the new drawing.

Thanks again for the help.

 

[hj]

A side inlet elbow is NOT an approved drainage fitting in many areas, because it does not have a "directional" sweep to it.

 

[mystryda]

So is it better now without the side inlet?

 

[hj]

IT is not only better, it is "legal" without the side inlet.