I live in PA and I replacing my single sink with a double sink vanity. I have opened the wall and replumbed (pvc/glue) so that i have two drain pipes (and two sets of water inlets, not important here). Before i drywall the openings back up, i test fit my vanity to make sure that everything fits through the holes in the back of the vanity AND fits below the sinks. This is my first job so it was worth a doublecheck even though i measured a million times. The good news is the right side (closest to the ultimate drain, the most downhill,) fits perfect. The waste pipe into the wall is directly behind the sink tailpipe and I have enough room to fit a p-trap.
I have some questions about the left side.
It too is directly inline, however it extends out a bit more because I elected to put on a AAC valve. I wasn't sure what the venting was prior to opening the wall. I found that the center drainpipe i removed did indeed have a vertical pipe running out of it and since i flushed/drained every device above me and nothing came out, i assume it is the vent. I installed the AAC anyhow, figuring you can't have enough venting, and I can always replace it by screwing in a seal if i need to. It could also act as a cleanout if i need to snake down the line (it is vertical so not optimum, and yes, it goes sink, p-trap,aac,wastelineintowall). Sure, it might be easier to remove the p-trap to cleanout but as i said the sink tailpipe is directly in front.
Unfortuntately, because i used a T on the protruding waste pipe, the place for the p-trap to connect to is a wee bit close to the sink tailpipe and the p-trap seems like it would be very tight.
Right now, prior to drywalling everything up, i could move the drainpipe a bit off center by cutting it and reattaching it a bit to the right. This would mean that I would have to move the one water inlet a bit more to the left since it would be protruding into the AAC if i don't move it. This may be the "best" route to go because if i have to have the right water inlet actually on the left of the drainpipe, i can extend it a bit so that i can secure it to the wall as right now it comes out right between the studs and kinda floats in mid air.
But i really think that is a bunch of work and i can leave it as is, and either
1. install everything and if the p-trap fits by cutting the horizontal extender peice down to .00001 inch to make it fit, who cares how long that is as long as it fits and why rework everything. I get the benefit of the p-trap being inline for maximum cabinent space underneath the bathroom sink. When i tested the configuration it was a real close fit and we were just holding things in place (sink, vanity against wall) so maybe I will get lucky.
2. Install everything and if the p-trap DOESN"T fit, simply put a 45 degree angle (horizontal) on the waste pipe and tilt the ptrap a bit around.
From everything I've read, its not wise to get a flex anything, both from a code pov and a hairgunk more often POV. It also seems as long as you aren't doing any vertical changes with your drainage thus affecting the p-trap and potentially making an s-trap or other syphon problem, then you should be good. Also, this does not seem to be a problem with length of horizontal rules as well.
So here are my questions:
A. Would you rework it so the drainpipe is offcenter or fiddle with it after?
B. If fiddling with it after, does it matter how long the horizontal part of the p-trap is as long as it gets a good seal?
C Since a vanity is covering up the holes in the wall, is there a code that says you NEED to drywall it back up? If so, how big of a hole are you allowed in the wall for the pipes to come out?
I suspect the answer is "By the time you researched all of this and typed all this up, you could have re-worked it and offset it, most plumbers do indeed know to measure the distance between the sink tailpipe and the waste pipe, and if they don't know, they off set it for just this reason, but since you are here and haven't done anything, you may as well just use a horizontal 45 degree pipe at the end of the tailpipe assuming it will fit in the gap. That was a really basic question, but we appreciate your honesty about how little you know. As for drywall, you should do as good a job as you can regarding the hole sizes to reduce minor drafts in the house and occasional crickets that may climb through the walls, but there is no specific code regarding that in PA, just personal preference on what is considered a job well done. Good luck"
I have some questions about the left side.
It too is directly inline, however it extends out a bit more because I elected to put on a AAC valve. I wasn't sure what the venting was prior to opening the wall. I found that the center drainpipe i removed did indeed have a vertical pipe running out of it and since i flushed/drained every device above me and nothing came out, i assume it is the vent. I installed the AAC anyhow, figuring you can't have enough venting, and I can always replace it by screwing in a seal if i need to. It could also act as a cleanout if i need to snake down the line (it is vertical so not optimum, and yes, it goes sink, p-trap,aac,wastelineintowall). Sure, it might be easier to remove the p-trap to cleanout but as i said the sink tailpipe is directly in front.
Unfortuntately, because i used a T on the protruding waste pipe, the place for the p-trap to connect to is a wee bit close to the sink tailpipe and the p-trap seems like it would be very tight.
Right now, prior to drywalling everything up, i could move the drainpipe a bit off center by cutting it and reattaching it a bit to the right. This would mean that I would have to move the one water inlet a bit more to the left since it would be protruding into the AAC if i don't move it. This may be the "best" route to go because if i have to have the right water inlet actually on the left of the drainpipe, i can extend it a bit so that i can secure it to the wall as right now it comes out right between the studs and kinda floats in mid air.
But i really think that is a bunch of work and i can leave it as is, and either
1. install everything and if the p-trap fits by cutting the horizontal extender peice down to .00001 inch to make it fit, who cares how long that is as long as it fits and why rework everything. I get the benefit of the p-trap being inline for maximum cabinent space underneath the bathroom sink. When i tested the configuration it was a real close fit and we were just holding things in place (sink, vanity against wall) so maybe I will get lucky.
2. Install everything and if the p-trap DOESN"T fit, simply put a 45 degree angle (horizontal) on the waste pipe and tilt the ptrap a bit around.
From everything I've read, its not wise to get a flex anything, both from a code pov and a hairgunk more often POV. It also seems as long as you aren't doing any vertical changes with your drainage thus affecting the p-trap and potentially making an s-trap or other syphon problem, then you should be good. Also, this does not seem to be a problem with length of horizontal rules as well.
So here are my questions:
A. Would you rework it so the drainpipe is offcenter or fiddle with it after?
B. If fiddling with it after, does it matter how long the horizontal part of the p-trap is as long as it gets a good seal?
C Since a vanity is covering up the holes in the wall, is there a code that says you NEED to drywall it back up? If so, how big of a hole are you allowed in the wall for the pipes to come out?
I suspect the answer is "By the time you researched all of this and typed all this up, you could have re-worked it and offset it, most plumbers do indeed know to measure the distance between the sink tailpipe and the waste pipe, and if they don't know, they off set it for just this reason, but since you are here and haven't done anything, you may as well just use a horizontal 45 degree pipe at the end of the tailpipe assuming it will fit in the gap. That was a really basic question, but we appreciate your honesty about how little you know. As for drywall, you should do as good a job as you can regarding the hole sizes to reduce minor drafts in the house and occasional crickets that may climb through the walls, but there is no specific code regarding that in PA, just personal preference on what is considered a job well done. Good luck"
