Hello to all.
If there is a plumber in the crowd, I am considering putting a sink and dishwasher in a freestanding island set of cabinets in a kitchen remodel I am going to be starting in January. I have seen these in multiple photo’s, but my question is how do you vent the sink? The island is on the first floor with a full basment underneath. Any ideas would be great.
Replies
If your local code official has no objections, a Studor vent, aka a vacuum break, works great for that application. If he won't go for that, you need to fabricate a loop that goes as high as practical under the counter, then run the vent to the nearest wall.
If an AAV is not allowed by your inspector, a special island loop vent is required.
Here is a drawing of how one is set up.
View Image
“It so happens that everything that is stupid is not unconstitutional.” —Supreme Court Justice Antonin Scalia
Do these "island loops" really perform adequately and reliably?
The drawing is a bit hard to make out but I notice that a cleanout seems to be an integral element on your drawing. Cleanout specifically for a vent? Is that very common?
I don't like AAVs at all, and I'm far from being a plumber but still skeptical about this loop arrangement.
BTW - I suspect that the AAV under our peninsula sink at my own house is malfunctioning intermittently. Is there anything I can do to trouble shoot this? Any thing I can do to make it work better? Are they typically screwed in place or would it be glued?
The AAV's I have used can be changed like a light bulb. Just unscrew and replace with a new one.
This loop's been working fine here (with dw) for the past dozen yrs:PAHS Designer/Builder- Bury it!
Here are a couple of drawings on the loop venting that are a little easier to see.http://www.theplumber.com/vent.html
http://www.codecheck.com/pg13_14plumbing.htmlHere is a slightly different version. Note that the cleanouts have been moved. But it can be used if you are on a slab.http://www.rd.com/images/tfhimport/2003/20031001_Ask_Handyman_page001img001_size2.jpg
Island loop vents have been around since the start of the plumbing code.
Very reliable.
A cleanout is required per code on the "foot vent" leg since it is assembled like a standard drain line & it is a vent that is below the flood level of the fixture.
Testing AAV's can be very difficult, studor vent¯ says in their directions that you "cannot" test against them.
A smoke test could work, but an intermittent problem is going to be very hard to find, since it would have to be in fail mode when the test is in progress.“It so happens that everything that is stupid is not unconstitutional.” —Supreme Court Justice Antonin Scalia
Although the "new" plumbing codes allow us to oversize a drain line to an island fixture and consider it vented because a gravity drain can't flood a line sized larger in diameter than the trap, many inspectors frown on using this piping/venting method for kitchen drains because of grease and debris.
Both the loop vent and air-admitance methods work quite well. Technically, the under-counter loop vent isn't correct because it's within the flood-level-rim of the fixture(s) being served, but most PI's will let that ride. In some areas, the DW would require a vacuum breaker above the counter top height. Once again - depends on the local PI and their interpretation of the codes.
The only way to know is to ask the PI ahead of time. Some PI's are fond of changing their minds, so it's best to get that in written approval form by submitting a drawing for review/sign-off.
Some PI's are fond of changing their minds,
Oh no say it aint so Joe. LOL
I'm gonna one up ya on that one------ 2 different inspectors same job, one signs off part of the system & the other comes on another inspection & says "you can't do that"“It so happens that everything that is stupid is not unconstitutional.” —Supreme Court Justice Antonin Scalia
Put up with that for 30+ years until a PI tried pulling that in my own new home during my plumbing rough-in. That's the day I decided - no more. If it's not in the book, I will not allow them to bully my firm around and they've come to realize we mean business. I invested in the "commentary" editions of the code books where each code rule is explained so it can be interpreted properly. By the book.
One told me he could flunk any work he doesn't like without giving the contractor a reason. I pointed out that the code book requires he give the contractor the reason and cite the passage referenced - in writing.
The unfortunate situation is that PI's can be appointed without any previous experience and, in my state, have two years to "learn" their job and pass a test. Makes for a damned interesting two years!
The reality is that HO's are getting ripped off. The permit fees have mushroomed by more than 300% (locally) while very few of the PI's have enough experience to know what they're looking at. Inspections are sub-par - at best. As a result, HO's are not getting what they're paying for and the permit/inspection process has become little more than a revenue generator for the municipalities.
In the late 1800's and early 1900's, plumbing codes were developed to protect the health of the nation. Pandemics of typhoid, cholera and dysentary were killing many thousands of citizens each year - as many as 25% of a city's population! Imagine one in four of your neighbors being well and healthy in the morning and dead by nightfall. Sanitary plumbing has saved more lives in the past 100 years than all of the medicines and medical practices.
PAH: One plumbing inspector I worked with years ago was so bad making up his own codes that the Contractors Assoc. took him to court; THAT SOLVED THE PROBLEM!!
..................................."If all else fails, read the directions"
Edited 11/30/2006 9:28 am ET by Shacko
In the late 1800's and early 1900's, plumbing codes were developed to protect the health of the nation. Pandemics of typhoid, cholera and dysentary were killing many thousands of citizens each year - as many as 25% of a city's population! Imagine one in four of your neighbors being well and healthy in the morning and dead by nightfall.
Do I get to pick which neighbors?
Joe H
T'would depend on what you sling at em as most of the aforementioned diseases were spread via fecal contamination!
Imagine the media frenzy we'd see if 100,000 folks died during a several-week period of time next summer!
BTW, SARS was spread via a clogged sewer in a NYC case.
BBTW: The current pandemics (bird flue) get their start in the very same Asian province as did the cholera and typhoid ones of old. No jets back then.
Being a member of IAPMO I feel your pain brother.
The 2 PI's I was referring to do the one up ya game with each other.
One is the Northwest president of IAPMO & the other is our union's code instructor.
I have known them both for 20yrs , one of them was my dad's apprentice back in the 60's.
“It so happens that everything that is stupid is not unconstitutional.” —Supreme Court Justice Antonin Scalia
I use code book with commentary, local PI alows Air Admitance Valves, he requires 2 inch drain AAV must be 12 inches above trap inlet. AAV must not be burried in wall, they have moving parts you must have access to them should they need changed. The one kicker is, it must be listed on permit application so you can pay the extra $50.00 charge for using AAV.