Venting / wet venting

[drfeno]

Hello,

I'm trying to design the drain plumbing for a 2nd bathroom I'm putting in. the bathroom is on the 1st floor of the building, but it sits on a foundation with a basement below so everything is quite accessible. The attached image shows a plan view of one proposed layout. My question is, is it OK for the vent to be positioned where it is, upstream of all the drainage? I would think it would be OK, but I don't know for sure. Also, the shower and toilet would be wet vented in this layout. Reading the code seems to allow this, but again I'm not sure. Also, are the pipe sizes OK. Of course all drains are pitched toward the building drain. Any thoughts would be welcome.

Thanks

 

[drfeno]

Maybe this image is better. the vent would come off the vanity drain trap arm. Also, the vent would make some turns before going through the roof. Pitch would always be maintained of course. the 2" horizontal would connect to the 3" toilet drain using a Wye, coming in from the top. The 2" shower drain would connect to the horizontal branch using a wye coming in from the side. Would this config pass inspection?

 

[frodo]

your drawing was a good drawing, i up voted it
but i could not resist playing with it, no disrespect intended

 

[drfeno]

Thanks, I have a couple of specific follow up questions regarding the actual fittings and their orientations.

1. Where the 2" horizontal wet vent ties into the 3" from the toilet, should the 2" come into it from the side or from the top? Reading the code regarding wet vents is a little confusing to the layman. it says connections must be horizontal. I would think it would be OK to come in from the top, but the side would be easier for the actual space I'm dealing with. I see you drew a little angle piece there, but due to the isometric, one could interpret that to mean from the top or the side.

2. Is it OK for the dry vent (once it exits the vanity trap arm on its way to exiting the roof) to make some twists and turns? Due to some interesting framing it cannot go directly up from the vanity. Of course it will have positive pitch.