I am in the process of renovating my basement and will be building a new bathroom as well. The contractor already installed the drains for a shower, a toilet and a sink and a 4" backflow valve (the Bow model with a trap door) because there was none previously.Now, since the old plumbing is exposed, I want to gain a bit of knowledge before I continue the renovations and call back the contractor. There is one pipe in particular that is a mystery for me. The old sink was about 3 1/2 - 4 feet from the stack. The pipe from the sink to the stack has a small back flow valve and another vertical pipe that goes up through the floor. This vertical pipe does not seem to be a drain from an installation on the floors above. Is it the vent? I thought at 4 feet the vent was not necessary. Has anyone seen a similar setup? If it's a vent and can be used for the new bathroom,I don't want the contractor to say he has to pass a new vent ($$$$$) or not connect to a vent whatsoever. See the attached picture. The dollar sign on the picture points to the main stack... it's an editing mistake, not an allegory (like "money down the drain").
Mystery pipe: could this be a vent?
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I am in the process of renovating my basement and will be building a new bathroom as well. The contractor already installed the drains for a shower, a toilet and a sink and a 4" backflow valve (the Bow model with a trap door) because there was none previously.Now, since the old plumbing is exposed, I want to gain a bit of knowledge before I continue the renovations and call back the contractor. There is one pipe in particular that is a mystery for me. The old sink was about 3 1/2 - 4 feet from the stack. The pipe from the sink to the stack has a small back flow valve and another vertical pipe that goes up through the floor. This vertical pipe does not seem to be a drain from an installation on the floors above. Is it the vent? I thought at 4 feet the vent was not necessary. Has anyone seen a similar setup? If it's a vent and can be used for the new bathroom,I don't want the contractor to say he has to pass a new vent ($$$$$) or not connect to a vent whatsoever. See the attached picture. The dollar sign on the picture points to the main stack... it's an editing mistake, not an allegory (like "money down the drain").
Kreemoweet
In the Trades
All traps require a vent. The vent for the Old Sink would go right where that mystery pipe is. It appears that an incorrect fitting was used to connect it with the Old Sink trap arm - you should ask your contractor to fix that, as well as to remove that illegal check valve.Since it appears to be
an 1 1/2 in. vent, it could only be used to vent a limited number of other fixtures, and, according to some
plumbing codes, could not be used to vent a toilet at all.
an 1 1/2 in. vent, it could only be used to vent a limited number of other fixtures, and, according to some
plumbing codes, could not be used to vent a toilet at all.
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Thank you for the clear and rapid answer, kreemoweet.
This is the conclusion I have drawn from what I have observed through the demolition, relocation of the pipes and the information you provided me:
1) The house did not have a main backwater installed on the main drain pipe (the one that goes to the city's sewer). Instead, there was a backwater valve for the old toilet and the small check valve installed along with the washroom sink. Otherwise, the whole washroom looked like it was built to save money, so the illegal valve and improper fitting you mentioned don't surprise me.
2) The new contractor had his plumber break the concrete, relocate the piping, install a drain for a shower, a new proper backwater valve, a toilet drain and a sink drain. Right now, the sink drain is just a 2" pipe that comes out of the ground up to about 3 feet. I imagine that the sink will attach to that and the pipe itself will have to connect to a proper vent.
In conclusion, and if I understood well, in addition to asking the plumber to remove the illegal check valve and correct the improper fittings, should I suggest that - if legal and efficient- he use the "mystery pipe" as a vent for the new bathroom?
Thanks again for the information!
This is the conclusion I have drawn from what I have observed through the demolition, relocation of the pipes and the information you provided me:
1) The house did not have a main backwater installed on the main drain pipe (the one that goes to the city's sewer). Instead, there was a backwater valve for the old toilet and the small check valve installed along with the washroom sink. Otherwise, the whole washroom looked like it was built to save money, so the illegal valve and improper fitting you mentioned don't surprise me.
2) The new contractor had his plumber break the concrete, relocate the piping, install a drain for a shower, a new proper backwater valve, a toilet drain and a sink drain. Right now, the sink drain is just a 2" pipe that comes out of the ground up to about 3 feet. I imagine that the sink will attach to that and the pipe itself will have to connect to a proper vent.
In conclusion, and if I understood well, in addition to asking the plumber to remove the illegal check valve and correct the improper fittings, should I suggest that - if legal and efficient- he use the "mystery pipe" as a vent for the new bathroom?
Thanks again for the information!
I suspect that check valve was put there in response to a prior event, even though flapper check valves are not up to the anti-backup task. Has there been sewer backups in that area? Ask the city sewer department and/or neighbors farther down the hill.
If there is potential sewer backup, consider putting in overhead sewers or a similar system. You mention a backwater valve. That should be the "normally open" type. If you can supplement that with a sump pump that will inject water downstream of the backwater valve, that can be effective. There are systems that add a pit to the yard with a system built into that. It is not cheap, but it is cheaper than overhead sewers. Sometimes a "program" will pay part of overhead sewers.
If there is potential sewer backup, consider putting in overhead sewers or a similar system. You mention a backwater valve. That should be the "normally open" type. If you can supplement that with a sump pump that will inject water downstream of the backwater valve, that can be effective. There are systems that add a pit to the yard with a system built into that. It is not cheap, but it is cheaper than overhead sewers. Sometimes a "program" will pay part of overhead sewers.
Thank you for the advice, Reach4. Thankfully we already have a sump pump. The area is not known for flooding or backups from the city but it's best to be prepared. I verify the sump pump periodically to make sure it is functional. In 7 years, it only went off once during an unusually heavy thunderstorm.
You could always ask, of course. Did he already make provisions for tie-in of the shower and the toilet vent?
Cacher_Chick
Test, Don't Guess!
A lot of people who are not plumbers mistakenly think that the main stack in a house is the "vent". Once there are fixture drains connected to a stack, is is a drain stack, not a vent. Only that section of the stack which is above the highest drain connection is a "vent".
Krik, the drains for shower and toilet are im place and are somehow tied to the sink drain which is currently a 2 inch pipe that extends from the ground up to about 3 feet. I guess this is a "wet vent" setup, but I am far from being knowledgeable in plumbing. I just needed a bit of guidance so as to know what to ask the plumber and also make sure that he is doing the job properly. These few exchanges on this forum have been the most helpful to date, far more helpful than what the plumber and contractor have explained to me up to now. Thanks guys, and have a most excellent week!
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