Vertical Wet Vent Question

[Ron Wren]

Wow what a great site. I have been reading for days and have learned a wealth of information.

From reading I have a grasp of wet venting but very limited. Most I have read show horizontal wet venting, are there different rules for vertical wet venting?

I have a bathroom I am redoing that the drain stack is offset about a foot from the plumbing wall the back of the upstairs bathroom. I am trying to limit as much as possible the pipes below the joists, and since I cant run vents horizontal the foot to offset to the plumbing wall i think i have a solution wet venting, will this work?

I plan on running the WC line to enter the 3 in stack the furthest down stream, then the shower above it, then staying 2 inch up to the lav and 2 in dry vent through the roof from there.

 

[Reach4]

You cannot turn that shower trap arm down before it hits its vent.

I am not assessing the rest of your drawing.

 

[Sponsor]

 

[Ron Wren]

You cannot turn that shower trap arm down before it hits its vent.

I am not assessing the rest of your drawing.

Wow, that was fast. Thanks for the reply Reach!

So is there a maximum slope before the vent, or does this run into the rule of not falling more than the diameter of the pipe? Just found that after reading your comment. Thanks Again!

 

[hj]

There is NO fitting that will make the angle you show going to the toilet. I would use a side inlet sanitary tee for the toilet and the shower into the side of it.

 

[Terry]

What hj mentions works.

 

[Cacher_Chick]

Listen to hj. Using his method, the WC & shower enter the stack at the same level, which is permitted. It is still a wet vent because the lav is connected above the other two fixtures. The alternative is individually venting the fixtures and tying the vents together (if desired), at least 6" above the flood rim of the highest fixture.

 

[Ron Wren]

I am seeing many many years of combined experience helping me, I am humbled, thank you all for your time!

This has helped my understanding immensely. I just have two more questions.

1) The reason I was dropping the shower and the WC down was because I thought when I made the offset coming down from the sink over to the stack that I would need to keep that at a 45 degree rather than running 1/4 per foot, because a vent cannot run flat until it is above the flood rim. But since this is a "wet" vet rather than a "dry" vent it can offset over at 1/4 per foot drop correct? (See dotted lines on attached drawing.) If this is the case I can keep the connection of the shower up in the joists keeping shower from dropping too much before the vent that Reach mentioned.

2) My drawings are not the best or to scale, so I think my drawing in the original post may have not giving the correct picture. I was planning on coming down vertically just a few inches then putting a 45 and then going at a 45 degree angle towards the stack then connecting a 22.5 degree to a Why on the vertical stack. Does the WC have the same rule as a shower or sink that it cannot drop further than the height of the pipe (3") before it reaches the vent, or are rules on the WC different since its trap is in the device and it fills itself after it drains?

Thanks All!

Edited: Sorry, image was original uploaded on its side I just fixed that.

 

[Cacher_Chick]

With a horizontal vent, the slope should not exceed 1/4" per foot. The idea is that the upper half of the pipe will have enough airspace to provide venting. This is also why the minimum size for the wet vent is 2" pipe. If the pipe slopes excessively or there is too much overall length, the vent is broken, and the trap can be siphoned.

In vertical wet venting, the stack must be vertical, with no offsets. An offset in the stack would be cause for an additional vent.

 

[Ron Wren]

Thank you cacher_chick, much appreciated!

I think my last question is on the WC drain. Is it allowed to drop more than the pipe height before it hits the vent like a sink or shower trap arm, or is the WC under different rules?

 

[Cacher_Chick]

Cut and Paste from the UPC-

The developed length between the trap of a water closet or similar fixture (measured from the top of the closet ring [closet flange] to the inner edge of the vent) and its vent shall not exceed six (6) feet.