I am remodeling my master bath, replacing a 5' whirlpool with a 6'. To do this, I have to move the tub away from the shower, and rotate it 90 degrees. The tub plumbing will be fine, it lines up with the existing drain line fine. The shower vent is my problem. The vent used to come up under the rim of the tub, then run into the wall and eventually the roof. Because the tub is moving, I need to rotate the vent line 90 degrees so it will come up inside a wall I am building. Is it OK for the vent to travel horizontal for about 2 feet, than rise up above the floor of the shower, and then to the existing vent line.
What I am confused about is that the vent will actually run horizontal for 2 feet, go straight up about 2 feet, then travel horizontal again for 5 feet, than go vertical into the roof vent. On other posts, I read that for a
1 1/2" pipe, the vent can be no more than 3.5' feet - does that mean before it goes vetical, or does that mean total length of the vent pipe?

Thanks
Mike

Wow 2 replies in one day with the same answer. If you are only concerned with the tub draining you can basically do anything except trap the line. Do you know what I mean by that? If you construct the vent line as you would a drain line, meaning you never have opposite direction of grade and you always have directional fittings in the correct position you should be fine. One exception is the vent must not begin flat. To see what I mean by that, check out this web site. http://www.masterplumber.com/Laws/UPCExcerpts.html#toolow
If you want to build the line according to local code, ask the inspector in that area.

I am remodeling my master bath, replacing a 5' whirlpool with a 6'. To do this, I have to move the tub away from the shower, and rotate it 90 degrees. The tub plumbing will be fine, it lines up with the existing drain line fine. The shower vent is my problem. The vent used to come up under the rim of the tub, then run into the wall and eventually the roof. Becasue the tub is moving, I need to rotate the vent line 90 degrees so it will come up inside a wall I am building. Is it ok for the vent to travel horizontal for about 2 feet, than rise up above the floor of the shower, and then to the existing vent line.
What I am confused about is that the vent will actually run horizontal for 2 feet, go straight up about 2 feet, then travel horizontal again for 5 feet, than go vertical into the roof vent. On other posts, I read that for a
1 1/2" pipe, the vent can be no more than 3.5' feet - does that mean before it goes vetical, or does that mean total length of the vent pipe?

Thanks
Mike

Hi Mike,

As long as you aren't draining anything into that vent then that makes it a dry vent and you can have as many horizontal runs in the vent as you wish.
The only thing is that you will have to maintain slope from the roof all the way down to the drain.
The 3.5 ft. rule for a 1 1/2" drain line concerns the distance from the fixture trap to the vent connection. It does not affect the vent itself. Good luck, Tom