Toilet Vent Simple Question - 2 floors

Users who are viewing this thread

wwhitney

Well-Known Member
Messages
5,230
Reaction score
1,314
Points
113
Location
Berkeley, CA
What if I install a Y for the vent between points A (the WC) and B and then run the vent to the nearest wall (which is behind the toilet)...this requires reversing the vent direction 180 degrees with some 45's from the Y but I presume that's acceptable as long as I maintain a minimum 45 degree slope on the vent, correct?
That works but do you really have the height for that under the slab? There are also much less convoluted patterns you could use, such as the one Reach4 suggested in post #17.

I assume this is a remodel? Do you have pipe at a ceiling level which is a dry vent through the roof, carrying no drainage? Is the trench shown in the OP still open?

Cheers, Wayne
 

PeterT

New Member
Messages
13
Reaction score
0
Points
1
Location
Los Angeles
That works but do you really have the height for that under the slab? There are also much less convoluted patterns you could use, such as the one Reach4 suggested in post #17.

I assume this is a remodel? Do you have pipe at a ceiling level which is a dry vent through the roof, carrying no drainage? Is the trench shown in the OP still open?

Cheers, Wayne

I hear you on the convoluted pattern...unfortunately the concrete is poured and we made a change on the 2nd floor that requires dumping the 2nd floor toilet into the stack that was originally going to only vent this 1st floor toilet...that's what created the need to vent it.

Yes, I do have the height under the slab if I keep the new vent at a 45 degree slope...if the slab was still open I would go with Reach4 proposal. Yes, I have a 2" pipe in the ceiling carrying no drainage that can vent this bathroom group.
 

Reach4

Well-Known Member
Messages
35,019
Reaction score
3,565
Points
113
Location
IL
If "vent in the picture is the 2-inch lavatory drain (the wet vent), you could do that. That wet vent can come in horizontally.

So you filled in the hole from your first photo. You might post a wider picture, and draw lines of what pipes are buried in the concrete.
 

wwhitney

Well-Known Member
Messages
5,230
Reaction score
1,314
Points
113
Location
Berkeley, CA
I hear you on the convoluted pattern...unfortunately the concrete is poured and we made a change on the 2nd floor that requires dumping the 2nd floor toilet into the stack that was originally going to only vent this 1st floor toilet...that's what created the need to vent it.
If you are going to open the concrete anyway, why not just add a new 3" drainage stack for the second floor, between the lavatory and the current WC vent?

Cheers, Wayne
 

PeterT

New Member
Messages
13
Reaction score
0
Points
1
Location
Los Angeles
If you are going to open the concrete anyway, why not just add a new 3" drainage stack for the second floor, between the lavatory and the current WC vent?

Cheers, Wayne
there's now another 6" slab on top of the old one...with rebar :eek: and a wall is now sitting over the main drain line so its easier to access a lateral vs the main line.
 
Last edited:

wwhitney

Well-Known Member
Messages
5,230
Reaction score
1,314
Points
113
Location
Berkeley, CA
I can't tell whether your photos show any 4" pipe, or if it's all 3". But your vent takeoff on the horizontal is going to be tight:

If the stack is centered 3" from the finish surface of the wall (maybe it's really 3.25" or 3.5"), then you have 15" center to center from closet flange to stack. If everything is 3", the horizontal run on a san-tee is 3", on a 3x3x2 wye is 5", and on a quarter bend (closet bend) is 3". So if you use all hubbed fittings, with 3" long sections of pipe so the hubs touch (hubs are 1.5" deep), you're at 3" (san-tee) + 3" (pipe) + 5" (wye) + 3" (pipe) + 3"(quarter bend) = 17", too much.

You switch to a 3x3x2 combo instead (rolled 45 degrees off upright), for some reason that has a run of only 4.5". And if you switch the quarter bend to a street quarter bend, that saves you 1.5" (one hub depth). That will get you to 15", if everything is 3".

So check it will all fit before opening the concrete, if it doesn't fit you can instead chop out a piece of the bottom plate and a stud and go to the horizontal building drain with the upstairs stack.

Cheers, Wayne
 

PeterT

New Member
Messages
13
Reaction score
0
Points
1
Location
Los Angeles
I can't tell whether your photos show any 4" pipe, or if it's all 3". But your vent takeoff on the horizontal is going to be tight:

If the stack is centered 3" from the finish surface of the wall (maybe it's really 3.25" or 3.5"), then you have 15" center to center from closet flange to stack. If everything is 3", the horizontal run on a san-tee is 3", on a 3x3x2 wye is 5", and on a quarter bend (closet bend) is 3". So if you use all hubbed fittings, with 3" long sections of pipe so the hubs touch (hubs are 1.5" deep), you're at 3" (san-tee) + 3" (pipe) + 5" (wye) + 3" (pipe) + 3"(quarter bend) = 17", too much.

You switch to a 3x3x2 combo instead (rolled 45 degrees off upright), for some reason that has a run of only 4.5". And if you switch the quarter bend to a street quarter bend, that saves you 1.5" (one hub depth). That will get you to 15", if everything is 3".

So check it will all fit before opening the concrete, if it doesn't fit you can instead chop out a piece of the bottom plate and a stud and go to the horizontal building drain with the upstairs stack.

Cheers, Wayne
Thanks so much! Yes, you are 100% correct to the inch...its all 3 inch and a 3x3x2 Y rotated slightly just barely gets the vent under the wall...but the street closet bend is key.

You got me thinking....I do have a 16x16 opening in the floor for the tub drain further downstream and the main line is 12 inches or so below the dirt level there... I dismissed adding a 3x3x3 Y at this location as I prefer not to use fernco couplings due to longevity ...is that a valid concern?

If I did this approach ( no concrete to cut), I could then set the tub trap a bit deeper in order to vent the tub drain before it dumps into the new 3" vertical.
 
Last edited:
Top
Hey, wait a minute.

This is awkward, but...

It looks like you're using an ad blocker. We get it, but (1) terrylove.com can't live without ads, and (2) ad blockers can cause issues with videos and comments. If you'd like to support the site, please allow ads.

If any particular ad is your REASON for blocking ads, please let us know. We might be able to do something about it. Thanks.
I've Disabled AdBlock    No Thanks