Is it OK to Vent a Toilet, Shower & Bath Sink into the Attic - at the Roof Ridge Vent?

[RogerPDX]

Stormerider says 'raise' the run - Jim says lower. Which is correct?

I will try to describe the situation again...

■ Shower vent now goes straight up through the roof. I want to eliminate this vent going through my new roof if possible.
■ About 8' away from the shower vent is a toilet vent that also has a sink venting into the vent. It goes straight up through the roof.
■ I want to connect the shower vent to the toilet vent as to eliminate one hole in my soon to be metal roof.
■ Should the connecting vent pipe, starting at the shower vent, run in an 1/4" per foot upward slant or downward slant when beginning at the shower vent running over to the toilet vent?

 

[Cacher_Chick]

Think of it like this- when liquid comes into a vent or a drain, the piping must be sloped so that it will flow to the building sewer.

 

[Sponsor]

 

[Storm rider]

We are all saying the same thing, we are just looking at it from different ends of the pipe. I said that from the shower to the existing roof vent (toilet) it would go up. Jim and Cacher said that from the toilet vent to the shower would go down.

 

[Cacher_Chick]

We are all saying the same thing, we are just looking at it from different ends of the pipe. I said that from the shower to the existing roof vent (toilet) it would go up. Jim and Cacher said that from the toilet vent to the shower would go down.

No, I am not assuming what the relationship is between the toilet drain and the shower drain, or if there is one at all.

All drain, waste, and vent piping must be pitched to drain to the building sewer.

In addition, as Jim mentioned, a vent must rise vertically until it is at least 6" above the flood rim of the highest fixture served by the vent.
If one were going to tie a shower vent and a toilet vent together, an inspector would be looking for the individual vents to rise vertically until they are at least 42" above the floor, at which point either or both of the vents could be run on the horizontal (with pitch) to join the other before proceeding vertically through the roof.

 

[RogerPDX]

If I do tie them together, they are in the attic which is 8.5' or a little more above the floor...
As long as I use the 'rule of thumb' to rise 1/4" per foot from the shower over to the toilet vent that goes through the roof (upward slant) it sounds like all is ok then.

Thanks for all your help!

 

[RogerPDX]

If I do tie them together, they are in the attic which is 8.5' or a little more above the floor...
As long as I use the 'rule of thumb' to rise 1/4" per foot from the shower over to the toilet vent that goes through the roof (upward slant) it sounds like all is ok then.

Thanks for all your help!

I had a plumber look in my attic yesterday and talk with me about combining my two vents together. He said that it is perfectly ok to cut the shower vent and 90º it over to the toilet vent. I had him read this thread, about making sure that the connecting vent pipe is angles 1/4" per foot and he said it is not necessary.

Am I missing something here? We are going to do the attic late next week, and I'd like to get this correct the first time.

Comments?

 

[Standardairconditioner]

I had him read this thread, about making sure that the connecting vent pipe is angles 1/4" per foot and he said it is not necessary.

It doesn't have to be precisely that, but it must be an obvious down slope because water will condensate in the interior of the vent pipe, and you want that dew and condensation to drain down. You don't want water hoaring in a pipe or elbow, which can eat away glue over the decades.

You certainly have enough workspace in your attic to slope the horizintal down hill enough. I've done wet vent installs where it was 1/4" lower over 4 feet, only because I could not raise the end of the pipe any higher. I always verify my horizontals with a level and make sure it is never zero slope.

 

[RogerPDX]

It doesn't have to be precisely that, but it must be an obvious down slope because water will condensate in the interior of the vent pipe, and you want that dew and condensation to drain down. You don't want water hoaring in a pipe or elbow, which can eat away glue over the decades.

You certainly have enough workspace in your attic to slope the horizintal down hill enough. I've done wet vent installs where it was 1/4" lower over 4 feet, only because I could not raise the end of the pipe any higher. I always verify my horizontals with a level and make sure it is never zero slope.

All the angled fitting that I saw at HD were either 90º, 45º maybe one more. If 90º is too horizontal and 45º is way too much drop, how do you get the drop correct? In my case these two vents are about 6' - 8' feet apart.

 

[Standardairconditioner]

All the angled fitting that I saw at HD were either 90º, 45º maybe one more. If 90º is too horizontal and 45º is way too much drop, how do you get the drop correct?

You're not using aircraft aluminum to build a space shuttle.

Plastic ABS/PVC is flexible and does bend.

 

[RogerPDX]

You're not using aircraft aluminum to build a space shuttle.

Plastic ABS/PVC is flexible and does bend.

I've got a pile of copper and was going to use it...

 

[Standardairconditioner]

You have a pile of 2" I.D. copper? And you want to pay your plumber doubletime more for labor to install something that will corrode in about 15-20 yeras, instead of half the time for plastic that will last 75 years?

 

[RogerPDX]

You have a pile of 2" I.D. copper? And you want to pay your plumber doubletime more for labor to install something that will corrode in about 15-20 yeras, instead of half the time for plastic that will last 75 years?

Naturally, I don't want problems & plastic is easy. It just looks cheap to me. I live on the ocean, so the air is plenty salty. There are a couple of copper vents up on the roof now, that are 53 y/o and they look fine. How does plastic hold up with the UV from the sun?

 

[Standardairconditioner]

Copper *is* flexible and it does *bend*.

The licensed professional you hire will know that.

Be sure to have your build requirements in writing for the contractor to follow, and that their work adheres to state code.

 

[RogerPDX]

Copper *is* flexible and it does *bend*.

The licensed professional you hire will know that.

Be sure to have your build requirements in writing for the contractor to follow, and that their work adheres to state code.

What about the plastic holding up with the UV from the sun?

 

[Jadnashua]

There's a little wiggle room when you use solvent welded plastic pipe fittings, so you can get your 2-degree pitch. PVC gets brittle when it gets long exposure to UV, but unless you have some impact, it will be strong enough to not become an issue. I don't know about your area, but in many places where it can get below freezing, while the pipe diameter can be smaller under the roof in the attic, it must be upsized going through the roof to prevent hoar frost from closing it off under worst case conditions. There's always some moist air in that pipe, and given the right conditions, it can freeze...you do not want it to close off the pipe and block it. Your local inspector will be able to tell you what's required.

 

[Cacher_Chick]

What about the plastic holding up with the UV from the sun?

We usually paint the stack coming out of the roof, which offers some UV protection, but many others do not. In the south, they run PVC above ground so I have trouble believing that it is an issue. PEX, on the other hand needs to be protected from UV.

 

[RogerPDX]

Would ABS be better than PVC?

 

[RogerPDX]

My roofer suggested that instead of combining the two vents into one vent, that we put a 90º angle on the vents and run them over to the eve (15' & 19' away) and have them stick out of the bird blocks under the eve. I could screen them to keep birds out.

The 15' vent is 2" - could be sized up to 3"
The 19' vent is 1.5" and could also be sized up.

Is this a good idea? Will it work?

 

[Bluebinky]

It's not confusing if you don't over think it. Water always goes down to the drain and air always goes up to the vent. No low spots to collect water and no high spots to collect air (trapping air seems to cause confusion and arguments, except for island sinks which cause even more confusion).

 

[RogerPDX]

So what about the distance at a nearly horizontal run to vent my toilet/laundry & my shower out the side of my eve / birdblocks? Does anybody know if this works?