I'm building a new bathroom in my third floor closet, and meet a plumbing problem. Since I don't want to drill a hole on the roof for vent pipe so I put the terminal on the eave. But it will not be straight and part of them will be horizontal, pls check the pic. I'll be very appreciate if some professors can give me an advice. Thank you very much!
Can I use a horizontal vent pipe?
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That does not work.
The vent on the lav can't go down, it must go up.
Cut a hole in the roof. We do it all the time.
The shower is not vented.
They don't allow venting below the roof. Besides, do you want smelly gas that low in the yard, and near windows? I think not.
The vent on the lav can't go down, it must go up.
Cut a hole in the roof. We do it all the time.
The shower is not vented.
They don't allow venting below the roof. Besides, do you want smelly gas that low in the yard, and near windows? I think not.
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hj
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The shower is not only unvented, but the way it is drawn it is also an "S" trap, and NO inspector would ever approve that "side vent". In addition, when the wind is blowing from that direction it would 'pressurize' the drainage system, which can cause all kinds of secondary problems. If that is the ONLY vent in the building, then your system does not have the minimum venting required.
Thank you Terry, Thank you HJ; but I have 2 questions.
1）how to solve the 'S' trap problem if my shower train is very close to the main stack? How long is the shower trap arm should be?
2)is it enough for 6 toilets to use one 2" vent pipe go through the roof? Because there is an exiting 2" vent pipe go through the roof on the other side of my house, but there are the stairs between my new bathroom and the exiting vent pipe so I'll have to run the new vent pipe along below the roof then reach the exiting vent pipe. The problem is that the new vent pipe will go down a little bit ( around 3') to reach the exiting vent pipe. But it's still higher than the highest train point. Is it an acceptable way to do it? (Coz I can't make a hole on the roof for some reason) thank you very much!
1）how to solve the 'S' trap problem if my shower train is very close to the main stack? How long is the shower trap arm should be?
2)is it enough for 6 toilets to use one 2" vent pipe go through the roof? Because there is an exiting 2" vent pipe go through the roof on the other side of my house, but there are the stairs between my new bathroom and the exiting vent pipe so I'll have to run the new vent pipe along below the roof then reach the exiting vent pipe. The problem is that the new vent pipe will go down a little bit ( around 3') to reach the exiting vent pipe. But it's still higher than the highest train point. Is it an acceptable way to do it? (Coz I can't make a hole on the roof for some reason) thank you very much!
Tom Sawyer
In the Trades
When waste goes down, a vent must go up. Vent to trap distances are published in your code book. Trap weir to vent must be 2 x pipe diameter.
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The S-Trap siphons.
The vent needs to be at the top of the trap arm, not below it. Those pictures are both very wrong.
The vent needs to be at the top of the trap arm, not below it. Those pictures are both very wrong.
If you have four more toilets, you need a 4" vent through the roof or the equivelent.
With three toilets, you need a 3" vent or equivelent.
A 2" vent does not vent an entire home.
You can't run the vents down like that. You're going to a lot of trouble designing a system that would not be approved anywhere.
With three toilets, you need a 3" vent or equivelent.
A 2" vent does not vent an entire home.
You can't run the vents down like that. You're going to a lot of trouble designing a system that would not be approved anywhere.
Jadnashua
Retired Defense Industry Engineer xxx
Let's summarize:
- vents can only go up - if they end up horizontal on any part, it must still have slope towards the drain line so it can't fill up with condensation or rain water
- traps need to be vented BEFORE the drain line turns down, or there may not be any air movement to the vent (IOW, it won't work!)
- the length of the trap arm depends on the size of the pipe...smaller pipes must be vented with a shorter trap arm than larger pipes (the slope could block the air flow, thus blocking the vent if it is too small or too long of an arm)
- the size of the vent is determined by the number of fixture units - each type of device has a prescribed number - you add them up, then look at it on the chart.
- if it regularly gets below freezing in your area, the part of the vent going through the roof may need to get bigger for a prescribed length before then to help prevent it from freezing over from the hot, moist air flowing out of it condensing, freezing, and blocking it off.
Plumbers go to school and OJT for often a number of years to figure this all out. There's more to it than many people think.
- vents can only go up - if they end up horizontal on any part, it must still have slope towards the drain line so it can't fill up with condensation or rain water
- traps need to be vented BEFORE the drain line turns down, or there may not be any air movement to the vent (IOW, it won't work!)
- the length of the trap arm depends on the size of the pipe...smaller pipes must be vented with a shorter trap arm than larger pipes (the slope could block the air flow, thus blocking the vent if it is too small or too long of an arm)
- the size of the vent is determined by the number of fixture units - each type of device has a prescribed number - you add them up, then look at it on the chart.
- if it regularly gets below freezing in your area, the part of the vent going through the roof may need to get bigger for a prescribed length before then to help prevent it from freezing over from the hot, moist air flowing out of it condensing, freezing, and blocking it off.
Plumbers go to school and OJT for often a number of years to figure this all out. There's more to it than many people think.
hj
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Both of your drawings are "illegal S" traps, and even if they were not, connecting the shower at that point would still induce siphonage from the toilet flowing past them. Most codes REQUIRE that the AREA, not diameters, of the pipes through the roof MUST be at least as large as the AREA of the incoming pipe, REGARDLESS of what the building's fixture load is.
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Hi every professors,
I drew a complete draft again, this is a 3 storey house plus basement, I need to add one bathroom on third floor, , one on second floor and 2 on basement. Now I have some questions about fitting and vent pipe.
1) where should I need to use WYE + 45 degree elbow? And where can I use San Tee?
2) should I need to run an individual dry vent pipe for the second floor and the basement other than using the soil stack as the wet vent? Can 2 water closet (WC) in different storey use one soil stack for venting?
3) should every fixtures has its vent? Even the trap arm is under the maximum length?
4) if the soil stack from upper storey need a 90 degree turn in basement's ceiling, should I need to use two 45 degree elbow instead of one 90 degree elbow?
5) what is the vent pipe size for the 2 bathroom in basement and one bath on second floor? 2" or 1 1/2 "?
Follow is the draft:
Thank you very very very much!
I drew a complete draft again, this is a 3 storey house plus basement, I need to add one bathroom on third floor, , one on second floor and 2 on basement. Now I have some questions about fitting and vent pipe.
1) where should I need to use WYE + 45 degree elbow? And where can I use San Tee?
2) should I need to run an individual dry vent pipe for the second floor and the basement other than using the soil stack as the wet vent? Can 2 water closet (WC) in different storey use one soil stack for venting?
3) should every fixtures has its vent? Even the trap arm is under the maximum length?
4) if the soil stack from upper storey need a 90 degree turn in basement's ceiling, should I need to use two 45 degree elbow instead of one 90 degree elbow?
5) what is the vent pipe size for the 2 bathroom in basement and one bath on second floor? 2" or 1 1/2 "?
Follow is the draft:
Thank you very very very much!
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