And now a plumbing question

[ejb]

Quick plumbing question guys...looking for a few options.

My new kitchen will have a 3' kitchen (double bowl) centered under a 8' window and I am trying to come up with a few options (hopefully the best option) for plumbing/venting it.

What would be the normal, or recommended, way to install the DWV lines to meet code requirements? Since I can't vent straight up, some sort of horizontal run will be needed...

Here are the options I can think of:

1. Have the trap drain a little over 3.5 feet to the right, to a veritical 2" DWV pipe, where water goes down and vent goes up - problem with this is if I go over 3.5', I understand I need to use a 2" pipe, and I can't put anything bigger than a 1 7/16 hole thru my load bearing studs and still pass code.

2. Do the above, but instead of running the horizontal thru the wall, run it thru the back of the kitchen cabinets until it gets past the window.

3. Have the draine pipe go straight down after the trap (1.5 inche for about 2" and then into a 2" pipe in the basement cieling) and then use a 1.25 vent that goes up from the trap, goes, right almost 4' and then turns vertical and connects with vent in the attic.

4. Option 4 would be to use an AAV (Air Admittance Valve), apprarentley they are not "code" in Mass - funny story though, I went to the local plumbing supply store and asked him if they were approved here or not - his answer: No, they are illegal in Mass...they are over their on the top shelf /forums/images/graemlins/wink.gif

I am quite certain I have entered the realm of analysis-paralysis on this one...someone PLEASE just tell me what the best (or even good enough) way is. /forums/images/graemlins/confused.gif



PS: Yes, I know if I pull a permit an inspector will tell me what I've done wrong...but assuming I go that root anyway, I'd rather do it right the first time.
/forums/images/graemlins/laugh.gif

 

[plumboy]

If I understand the window is 8' wide....Here we can run 2" 5' from vent to trap,but that doesnt help you.You can run a loop vent,we call them mexican loops for some reason here.The code book there should have diagram if they are approved fo mass.

 

[plumboy]

Actually option 3 sounds like what we do here,not good for outside wall/window jack tho.

 

[midlf]

Here we can run the vent up until it is 6" above the highest possible water level and then do a 180 with it heading down where is ties into a vent line in the basement or below the floor. Vent lines must all be pitched to drain. I suspect this may be what is called the "mexican" connection by another poster.

 

[EddieWalker]

Why put in a sink that is split evenly in the middle? Having it split with one side larger than the other makes it more practical and user friendly.

Never did a window that large over the sinke, but since it's just a vent, why not put a cleanout on the outside wall and then ninety it off to the side and up?

The cleanout allows you to get in there if you have a problem and the line is still vented.

Eddie

 

[Inspector507]

Eddie,
We have an offset sink with one side larger than the other, and frankly we hate it.

 

[kenmac]

Can't he just over size drain with out the vent Like you do on the island type sinks ?We use 3-4'' drain on these & they don't make us use a vent.

 

[midlf]

Using a 3 or 4" drain is interesting. Anyone know if this is a national recommended code item or is it just local?

 

[CurlyDave]

My new kitchen will have a 3' kitchen (double bowl) centered under a 8' window and I am trying to come up with a few options...

. Have the trap drain a little over 3.5 feet to the right, to a veritical 2" DWV pipe, where water goes down and vent goes up - problem with this is if I go over 3.5', I understand I need to use a 2" pipe, and I can't put anything bigger than a 1 7/16 hole thru my load bearing studs and still pass code.

Seems to me that you could use 2x6 studs in that one wall, get your drain in, meet code and live hapily ever after...

In Oregon, 2x6 studs are required in all exterior walls now. It is not a strength issue, it is supposedly a matter of insulation thickness. Actually, I suspect it is a giveaway to the lumber industry.

 

[plumboy]

Theres no way we could plumb a sink without a vent here,I couldnt imagine how messy it would be to use a 3-4" trap/drain for a sink.Island sinks are plumbed with the loop vents or when you dont want to chew wood up.2x6 walls would be a great ideal for any plumbing on an outside wall,but I'm sure his walls are already built.