Hello, thanks ahead of time for any help you can offer.

My house is a cape cod. I'm converting the attic into master suite with half bath. (yes, I had it checked, I have egress/access/structural support). My question deals with reventing. It is my understanding that all current vents have to be relocated so that they tie into the main stack above the highest fixture drain tie-in. no problem. However, what about my fixtures that are not currently vented, do they need to be vented now that I'm adding a toilet(and sink) on second floor? Or do they still get by on the "within 'x' distance to stack/doesn't need to be vented" rule of thumb?

I appreciate you're help,

Louie

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Originally Posted by atticguy

hello, thanks ahead of time for any help you can offer.

my house is a cape cod. i'm converting the attic into master suite with half bath. (yes, i had it checked, i have egress/access/structural support). my question deals with reventing. it is my understanding that all current vents have to be relocated so that they tie into the main stack above the highest fixture drain tie-in. no problem. however, what about my fixtures that are not currently vented, do they need to be vented now that i'm adding a toilet(and sink) on second floor? or do they still get by on the "within 'x' distance to stack/doesn't need to be vented" rule of thumb?

I appreciate you're help,

louie

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Hey Louie,

You said," it is my understanding that all current vents have to be relocated so that they tie into the main stack above the highest fixture drain tie-in"
Almost but not quite. You may revent back into a existing vent as long as it's at least six inches over the FLOOD RIM of the highest fixture not the drain tie-in.
You also asked." however, what about my fixtures that are not currently vented?"
ALL and ANY fixtures that are trapped MUST be vented, wet vented or revented. I think I know what you're asking here. You may discharge your attic group into the main stack, unless the attic group will be discharging past a revent into the main stack, venting the attic group off the lavatory which can then be revented into any vent that goes out the roof. Does this answer your question? Tom

Thanks for getting back to me

A few things I new clarification on:

1)higher than "flood rim", if I add a sink in attic. Then the revent must be higher than the overflow valve on the sink?

2)i do have fixtures on my 1st floor that are not vented. They tie right into the main stack... they are my shower and sink.

3)what exactly is "venting off a lavatory.

I will post pictures and diagrams so we can be on the same page, I should have them early in the morning. :confused:

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Originally Posted by atticguy

thanks for getting back to me

a few things i new clarification on:

1)higher than "flood rim", if i add a sink in attic. then the revent must be higher than the overflow valve on the sink?

2)i do have fixtures on my 1st floor that are not vented. they tie right into the main stack... they are my shower and sink.

3)what exactly is "venting off of a lavatory.

i will post pictures and diagrams so we can be on the same page, i should have them early in the morning. :confused:

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1)higher than "flood rim", if I add a sink in attic. Then the revent must be higher than the overflow valve on the sink?

No, it must be at least 6" over the RIM of the highest fixture.

2)i do have fixtures on my 1st floor that are not vented. they tie right into the main stack... they are my shower and sink.

you're not gonna like this. The fixtures on the first floor are indeed vented if they are within 5' of the stack they discharge into. However,(and here comes the zinger) you MAY NOT discharge a major fixture, (such as a toilet) past them. What you can do is 45 another 3" main stack raiser from just below the first floor branch up to the attic and discharge the attic group into that venting off the attic lavatory.

3)what exactly is "venting off of a lavatory.

you come off the lavatory drain with a tee 18" off the floor. You stub out of the branch to pick up the lav. From the top of the tee you run through the roof or revent back into another vent. If you have tied the lavatory drain into the 3" branch from the toilet the group will have been vented. Hope this clears things up a bit. Sorry about the second stack but that's code. Tom

Hello again Tom,

I opened up my first floor bath wet wall, the tub and lav are both 'vented through the lav'. However, they do tie into the main stack, as does my basement laundry tub vent and kitchen sink vent. I plan on redoing the first floor bath anyway.
1)so my question is ,"can i just extend the vents to attach to the main stack higher up (higher than 6 above the rim of my future attic sink)?" of course everything is now cast and galvanized and I plan to switch to pvc and copper.
2)is there a rule for how close you can get to the underside of the roofline for vent tie-ins? I am concerned about attaining the correct height of the sink as my roof is steeply sloped. It's going to be close.(I'd rather not change the main vent location and do some roof work)
3)the first floor toilet doesn't have to be revented, does it?? How would that work?

Please forgive my ignorance, I'm a novice

Thanks again for all of your advice, you're a lifesaver.

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Originally Posted by atticguy

hello again Tom,

i opened up my first floor bath wet wall, the tub and lav are both 'vented through the lav'. however, they do tie into the main stack, as does my basement laundry tub vent and kitchen sink vent. I plan on redoing the first floor bath anyway.
1)so my question is ,"can i just extend the vents to attach to the main stack higher up (higher than 6 above the rim of my future attic sink)?" of course everthing is now cast and galvanized and i plan to switch to pvc and copper.
2)is there a rule for how close you can get to the underside of the roofline for vent tie-ins? I am concerned about attaining the correct height of the sink as my roof is steeply sloped. it's going to be close.(i'd rather not change the main vent location and do some roof work)
3)the first floor toilet doesn't have to be revented, does it??? how would that work?

please forgive my ignorance, i'm a novice

thanks again for all of your advice, your a lifesaver.

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1)so my question is ,"can i just extend the vents to attach to the main stack higher up (higher than 6 above the rim of my future attic sink)?" of course everything is now cast and galvanized and I plan to switch to pvc and copper.

Yes you may. That would be the alternative to cutting in another stack to pick up the attic group. Just don't leave any vents out.

2)is there a rule for how close you can get to the underside of the roofline for vent tie-ins? I am concerned about attaining the correct height of the sink as my roof is steeply sloped. It's going to be close.(I'd rather not change the main vent location and do some roof work)

There is no rule about where you tie a revent in. Just so it's at least 6" over the flood rim of the highest fixture.

3)the first floor toilet doesn't have to be revented, does it?? How would that work?

You shouldn't have to vent the first floor toilet as it will be wet vented by the other vents when you revent them back in your attic.

Please forgive my ignorance, I'm a novice

Nothing to forgive. Plumbing can become complicated at times, especially in a remodel. Your asking intelligent questions. I only hope I'm giving intelligent answers. Best of luck, Tom

3)the first floor toilet doesn't have to be revented, does it??? how would that work?

you shouldn't have to vent the first floor toilet as it will be wet vented by the other vents when you revent them back in your attic.

Could you clarify this for me? The first floor toilet is attached to the stack with a closet bend with the stack continuing upward (pretty standard). I want to (after reventing everything) add a toilet with another similar closet bend that has a side inlet for the lav drain, in the attic. I guess I'm just unclear how the 1st floor toilet trap pressure would be equallized if the upstairs toilet is flushed and the downstairs toilet is in its path. Is it because the diameter of the stack won't be filled completely?

Also, how can I attach pics or diagrams?

Thanks again!

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Originally Posted by atticguy

3)the first floor toilet doesn't have to be revented, does it??? how would that work?

you shouldn't have to vent the first floor toilet as it will be wet vented by the other vents when you revent them back in your attic.

could you clarify this for me? the first floor toilet is attached to the stack with a closet bend with the stack continuing upward (pretty standard). I want to (after reventing everything) add a toilet with another similiar closet bend that has a side inlet for the lav drain, in the attic. i guess i'm just unclear how the 1st floor toilet trap pressure would be equallized if the upstairs toilet is flushed and the downstairs toilet is in its path. is it because the diameter of the stack won't be filled completely?

also, how can i attach pics or diagrams?

thanks again!

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" i guess i'm just unclear how the 1st floor toilet trap pressure would be equallized if the upstairs toilet is flushed and the downstairs toilet is in its path. is it because the diameter of the stack won't be filled completely?"

If the lav and tub connected into the run ftom the first floor toilet then that toiletwould have been wet vented. However, since you indicate that the first floor toilet is connected direct then it vents through the stack. You are correct when you say that at no time will the stack be full enough to stop the venting action. However the attic toilet will be wet vented by the lav vent. You'll be fine if you just run the first floor up and revent back to the stack. Tom

However the attic toilet will be wet vented by the lav vent.

I didn't think the attic toilet would need to be wet vented, isn't the stack continuing through the roof enough? I emailed you some pics. I'm sorry for troubling you so much. I'll be out of your hair soon.

Thanks again, you really are helpful!

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Originally Posted by atticguy

However the attic toilet will be wet vented by the lav vent.

i didn't think the attic toilet would need to be wet vented, isn't the stack continuing through the roof enough? i emailed you some pics. i'm sorry for troubling you so much. i'll be out of your hair soon.

thanks again, you really are helpful!!

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It's wet vented the minute you tie the lav drain to the toilet drain although you are correct. It doesn't have to be but by draining the lav into it it just is. I'll be watching for your pics. Tom

Hey tom,

OK, I think I have a single question which, once answered, will solve all of my life's problems. Well at least the plumbing ones. Hehe. :D here goes.

Cape cod house. One main stack. There are only two plumbing fixtures in the entire house. There are two toilets(let's say they are a very strange family who drink out of/bathe in/ and wash dishes in their toilet... humor me). Toilet #1 on first floor which ties directly into stack.
Toilet #2 is directly above it in attic which also ties directly into stack. No reventing anywhere. Is this house OK? And why or why not. :confused:

For all that you have done for me and others on this site, I thank you.

Louie

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Originally Posted by atticguy

hey tom,

ok, i think i have a single question which, once answered, will solve all of my life's problems. well at least the plumbing ones. hehe. :D here goes.

cape cod house. one main stack. there are only two plumbing fixtures in the entire house. there are two toilets(let's say they are a very strange family who drink out of/bathe in/ and wash dishes in their toilet...humor me). toilet #1 on first floor which ties directly into stack.
toilet #2 is directly above it in attic which also ties directly into stack. no reventing anywhere. is this house ok? and why or why not. :confused:

for all that you have done for me and others on this site, i thank you.

louie

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You answered your own question a few posts ago. You said."" i guess i'm just unclear how the 1st floor toilet trap pressure would be equallized if the upstairs toilet is flushed and the downstairs toilet is in its path. is it because the diameter of the stack won't be filled completely?"
BINGO! Even if potty#1 and potty#2 were flushed at the same instant the discharge from both toilets wouldn't block a three or four inch stack from venting. When flushed the traps in a toilet are replenished from the tank upon flushing.The only way a trap seal can be pulled out of a toilet is if a tub is drained or a washer discharges in the same branch past a blocked vent putting suction on the toilet trap seal. Toodles, Tom

Hey tom,

Thanks for all of the help. I feel much better about tackling this project now. Sorry about being so persistent, I just want to make sure I have all of my bases covered. You've been a great help.

I'm sure I'll be back soon when I run into another issue. :o

Sincerely,
Louie