vent pipe

[brando27]

I have a wall between my shower and tub that I want to remove. The vent pipe comes straight down that wall and ties vertically in between the shower drain and tub drain. Can I run the vent pipe horizontally from that point under the subfloor for about two feet and then up the back wall?

[LazyPup]

NO,,A vent MUST run vertical from the drain line until it reaches an elevation at least 6" higher than the flood level rim of the highest fixture served by that vent.

[brando27]

What would be my other options?Thanks for the help.
I have about 18" to work with.

[LazyPup]

I would need to see the physical layout and know which code you are under.

If you are not sure which code you are under let us know what city, county & state you are in and I can find out which code applies.

It is possible that you could extend or reroute fixture arms (drain from fixture to vent).

[pushkins]

Have you thought about leaving a knee wall between the tub and shower, this way you could have your vent line run high enough to meet code?
Also, what does this section of the vent line serve, is it just the tub and shower, if so that means the knee wall would only need to be high enough to be 6" taller than the tub over flow.

[LazyPup]

The kneewall is a good idea but be careful here. even though it may appear to only be venting the tub and shower, the lavatory may be wet venting off the drain line. In that case you may not have a horizontal offset in the vent line until it reaches and elevation 6" higher than the vanity top.

[brando27]

First Off, Much thanks for all the info!
What I would like to do is have knee wall that comes to the top of the tub.Which is about 18" from the floor.
On the tub side of the wall the drain is about 12" from the vent pipe and on the shower side the drain is about 18" form the vent pipe.From where they all tie in, I have about 20" to the back wall.Thanks again for all the suggestions.

[LazyPup]

I think I may have a real simple solution for you.

In the plumbing business if a line runs horizontal or rises at an angle up to 44" it is said to be a Horizontal line and if it rises at any angle from 45deg to vertical it is said to be a Vertical line.

Code requires that all vents must run vertical until they reach an elevation at least 6" above the flood level rim of the highest fixture served by that vent, therefore you could cut the vent near the floor at its present location and run it at a 45deg angle from that point to the rear wall in the kneewall, then continue straight up in the rear wall, in that manner even though you have made an offset that offset is technically a vertical offset and the entire line would be considered a vertical line thus it would meet code standards.

[brando27]

I am about to do my shower pan, and I was wondering what type of cement I should use for the preslope and the top slope? I know a lot of people mix portland and sand but can I use any of the premixed bags(from Home depot or lowes)????
Thanks

[pushkins]

You basically need mortar, make the mix as dry as you can, as you trowel it into place the moisture will come up to he surface. You will need one layer of mortar 1 1/2" thick with at least a 1/4"/foot slope to the drain. Then your vinyl liner (Lowe's/Home depot have them) then your final layer of mortar.
Note: Make sure the mortar is dry before adding thin set and tiles.
A liner is imperative unless your using a Schluter or Wedi system.