Kitchen Island Sink Vent
#1
Kitchen Island Sink Vent
In a foot/loop vent for an island sink, how important is the height of the loop (relative to the maximum water level in the sink)? As long as the sink drains into the drain side of the loop where it is vertical, is it O.K. to re-route the upper portion of the loop with 30 or 45 degree bends to as to turn the loop 90 degrees and position it to the back of the cabinet. Fortunately, I have a 27" deep base cabinet with which to work and I was wanting to position the upper part of the loop to the back of the sink and get it as high as possible.
Last edited by txdiyguy; 06-22-05 at 01:45 PM. Reason: correct spelling
#2
This is more complex than you would imagine.
Your answer depends entirely on what code you have. There are fundamental differences for island drains with the UPC and IPC. Without knowing which code to follow, we can not give you a proper answer.
Your answer depends entirely on what code you have. There are fundamental differences for island drains with the UPC and IPC. Without knowing which code to follow, we can not give you a proper answer.
#4
Plumber 2000 used to post pictures of the differences between codes which was a great source of info.
Go to this link:
http://www.codecheck.com/pg13_14plumbing.html#drains
and look at the island drain for IPC. Now see what they did with 45's. Is this something like you want to do?
Good luck with your project.
Go to this link:
http://www.codecheck.com/pg13_14plumbing.html#drains
and look at the island drain for IPC. Now see what they did with 45's. Is this something like you want to do?
Good luck with your project.
#5
Basically, that's what I have in place. The drawing doesn't give any dimensions or reference elevations. Seems like I read somewhere that it is important to have the uppermost part of the loop as high as possible. The problem I have is that the return vent part is directly under the sink and, as such, won't be very high unless it is offset and routed back and up behind the sink. The current arrangement is exacly like the drawing. In my case, the part of the setup with the two sanitary tees is at the front of the base cabinet and the vertical part of the return vent that has no fittings is at the very back of the cabinet. What I think needs to be done is, just above the sanitary tee (for the sink drain), use a 45 deg bend to clear the bottom of the sink and (or maybe a 90 deg), once it is clear of the sink, 45 deg (or 90 deg) back up to complete the loop behind the sink with the uppermost part of the loop (the 90 deg bend) just under the underside of the countertop. Like I said in my original post, I have a 27" deep base cabinet rather than the normal 24" deep cabinet so I have at least a 3" clear space to configure the high point of the return vent.
#6
I never got any response to my question on "how important is the height of the loop (relative to the maximum water level in the sink)?"
Googling "kitchen island sink vents", I ran across this on the Santa Anna, CA site:
"When roughing in the island sink, the vent of the sink must extend as high as possible under the island cabinet, but no less than the drainboard height."
What are they talking about when they say "drainboard height"? One would think it was the level of the countertop, but that would be impossible to achieve and not be exposed.
Googling "kitchen island sink vents", I ran across this on the Santa Anna, CA site:
"When roughing in the island sink, the vent of the sink must extend as high as possible under the island cabinet, but no less than the drainboard height."
What are they talking about when they say "drainboard height"? One would think it was the level of the countertop, but that would be impossible to achieve and not be exposed.
#7
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I'm a little bit more intrigued by notuboo's inital response to the question:
"Your answer depends entirely on what code you have. There are fundamental differences for island drains with the UPC and IPC. Without knowing which code to follow, we can not give you a proper answer."
Does this mean that venting properties in a situation like this vary by community plumbing codes? Aren't the physics the same no matter where one lives and under which plumbing code one falls? A kitchen island is a kitchen island and needs to be vented properly, no matter who the sheriff is... Please don't take my comments the wrong way, as I do not mean to sound sarcastic, argumentative or anything like that. I'm just curious, but to the point.
I'm just as curious as txdiyguy because I'm currently designing my new house and the kitchen is going to have an island as well.
"Your answer depends entirely on what code you have. There are fundamental differences for island drains with the UPC and IPC. Without knowing which code to follow, we can not give you a proper answer."
Does this mean that venting properties in a situation like this vary by community plumbing codes? Aren't the physics the same no matter where one lives and under which plumbing code one falls? A kitchen island is a kitchen island and needs to be vented properly, no matter who the sheriff is... Please don't take my comments the wrong way, as I do not mean to sound sarcastic, argumentative or anything like that. I'm just curious, but to the point.
I'm just as curious as txdiyguy because I'm currently designing my new house and the kitchen is going to have an island as well.
#8
Physics are the same, within our universe... but that is for a different forum...
You absolutely need to talk to your local code inspector about this. He is the one who decides what his local codes actually mean.
The island vent is just 1 example of problems you will run into when comparing UPC and IPC.
txdiyguy: You are right about the loop can not be higher than the drainboard, but wording is everything in code. The wording you cited is under UPC. IPC mentions "the bottom of the drainboard".
Take it to the underside of the countertop before starting the return loop. You should have pleanty of room with your wider cabinets.
You absolutely need to talk to your local code inspector about this. He is the one who decides what his local codes actually mean.
The island vent is just 1 example of problems you will run into when comparing UPC and IPC.
txdiyguy: You are right about the loop can not be higher than the drainboard, but wording is everything in code. The wording you cited is under UPC. IPC mentions "the bottom of the drainboard".
Take it to the underside of the countertop before starting the return loop. You should have pleanty of room with your wider cabinets.