DVW planning question

[almostdone]

I'm putting a bathroom in a summer cottage. Fixtures include a lav (1.5" drain line), shower (2"), and toilet (3"). All three drains come through the subfloor within 3 feet of a 2" vent pipe. p-traps for the lav and shower would be installed below the subfloor.

I'd appreciate any input you all might have on the following DVW scheme.

The building drain will be 3". Here is a schematic of what I was planning to do. Sorry for the crude diagram. Rotating it 90 degrees counterclockwise gets thing right verticalwise.

(CLEANOUT)
3
Y 2 2 2 2 2 2 2 2 2 2 2 (VENT)
3
3
Y 1.5 1.5 1.5 (LAV P-TRAP WASTE ARM)
3
3
Y 2 2 2 2 2 2 (SHWR P-TRAP WASTE ARM)
3
3
Y [45] 3 3 3 3 3 3 3 3 3 3 3 (WC)
3
3
3
(OUTLET)

The distance from the toilet flange to the vent riser is less than 3 feet.


Will this system work? Is wet venting the shower and lav upstream of the toilet like this ok? The distances from the p-traps to the 3-inch line will be very short (less than 3 feet in both cases). Any thoughts would be great. Thanks.

 

[hj]

drains

It would never pass inspection in any area I am familiar with, and according to one source only a licensed contractor can do plumbing installation in MA.

 

[Sponsor]

 

[Prashster]

In my area (granted, it's NJ) each fixture has to be individually vented. If you are in fact allowed to do yr own plumbing in MA, can you run vents thru a nearby wall?

 

[Coach606]

Wet vent?

Is what he's proposing considered a "wet vent"?

Other than the problem of doing your own plumbing, what's the issue here with his plan? I'm getting ready to run a wet vent system as well with two lavs vented in the wall and then a wet vent pipe running first to a tub and then to a w.c.

Is mine okay? I assume it is as I got the design from a very knowledgeable person on this forum. If mines, okay, why is his a problem?

Thanks. Here are some pics of my design. The extra vent to the tub is just in case it is more than 6' from the original wet vent.

 

[Dunbar Plumbing]

Wet venting "used" to be code in my area 40 years ago.

Now, when I have to unclog drains in these wet vent systems, it seems that clogging of the vents is a norm. Not in my opinion the correct way to plumb.

In Ky each fixture must have its own individual vent, period. No exceptions and I sleep good at night that I follow that code whenever that issue presents itself.

All the rest is airplane plumbing with no logical reason for the shortcuts.

 

[Terry]

That is a horrible drawing.

Any plumber or inspector would laugh at that.

Why would you want to save $10 and cause yourself so much grief?

http://www.iapmo.org/common/ROP2004/upc04rop/preprint/ch9.pdf

 

[Coach606]

Better drawing...

I did that drawing in about five minutes just to get the drawing in.

I didn't come up with it, but got the basic design from a guy on this site who says he's a plumber in NJ. The guy's addie is TBPLUMBLOCO. We spent a lot of time discussing it.

I could make a neater drawing and show all the fittings, but what you're saying is that each fixture needs its own vent and that I pretty much should design a circuit vent?

Wet vents are okay according to IPC 2003, which is my code here in Illinois. Part of the issue is that zoning problems keep me from dormering this area. The location of our fixtures is unusual so the wet vent seemed like a good plan.

I'm not trying to save $10 and make a mistake. I asked anyone on this board to help with the design and a few people stepped up and helped to create this.

Care to help me come up with a better plan?

Here's a link to the original thread. https://terrylove.com/forums/showthread.php?t=7276 You can check out our discussion and the drawing posted by TBPLUMBLOCO, who's a plumber in Jersey.

TBPLUMBLOCO, I know this isn't your drawing, but I assume you still think the idea is sound. Care to weigh in?

If this is a bad idea, I'd like some suggestions for a better way to handle things.

 

[Terry]

http://www.iapmo.org/common/ROP2004/upc04rop/preprint/ch9.pdf

Read section 908.0 Vertical Wet Venting.


The UPC code says you can do a "vertical" wet vent on the same floor for a one or two fixture unit fixture, if you increase the pipe one size.
With UPC, the tub alone, with the 3" fixture units would req

Your drawing shows a "three fixture unit" (tub) and two "one fixture unit" fixtures (lav) done horizontally.

If you buy a permit, like the rest of us do, I'm sure the inspector will have an oppinon on it too.

Homes when they are sold, must declare if any non-permited work has been done on them.

Lawyers love these things.

If you are under IPC code, I'm not much help there.
Our inspectors have been fighting against adopting the IPC for years.
They prefer that we install traps and trap arms that do not clog all the time,
like they must in the East.

Vertical wet vents like in the drawing below work fine.

 

[Tbplumbloco]

wet venting

Yes Coach I will comment,What we discussed is the wet vent method that is legal according to the IPC which has jurisdiction in OHIO as well, and I insisted that you oversize the tub and lav drains to 2" excluding the p-traps which can still be 1.5".I have installed this type of DWV piping from COLUMBUS to DAYTON,new constuction+remodel,the only problems I have seen + done service work related to abusing AAVees.Your Inspector has the final say,if he does not approve the wet vent method then ask him what he is looking for.Drains clog all the time,wet vented,individually vented etc.etc.There is a lot of info on the net but sometimes very little substance.Good Night I am going to dreamland.

 

[Coach606]

here's my code...

I respect everyone's oppinion on this. Here's what the IPC 2003 code book says. It is used by my city.

"Any combination of fixtures with two bathrrom groups located on the same floor level are permitted to be vented by a wet vent. The wet vent shall be considered the vent for the gixtures and shall extend from the connection of the dry vent along the direction of the flow in the drain pipe to the most downstream fixture drain connection to the horizaontal branch drain. Only the fixtures within the bathroom groups shall connect to the wet vented horizontal branch drain."

Sounds like IPC 2003 and thus my town should be okay with it. Hey, I appreciate the opinions.

But, man, that was hardcore.

What's up with the inspector's range of power, anyway? I mean, can the guy say that he doesn't like my drawing and not sign the permit? Can he say that he doesn't like wet vents even if the code our town uses is fine with it?

Terry, what do you recommend? Straight up circuit venting? I suppose I could do that, but I'd have to drill a lot of holes in the wall leading to the bedroom and I know that wall is going to be load bearing for a barrel dormer above it. It's a problem because the w.c. is on one wall, the two lavs on the opposite, and the tub is in the center of the room. Zoning setbacks and some unconventional taste by the wife. Most plumbing solutions anticipate all the fixtures on one wall. That can't work for me. In addition, the basement stack can really only be tapped into by sending the vertical waste line down in exactly the right spot or else it runs into a whole slew of ductwork from the hvac mechanicals room. That's why the wet vent is so helpful here.

I think I'm going to stick with the wet vent, do a nice drawing and then try to visit with my inspector ahead of time and see what he says.

I'll let you know if he laughs at it. TBPLUMBLOCO, thanks for responding. I don't think I'd have gotten any sleep if you hadn't.

ANYONE ELSE WANT TO COMMENT ON WET VENTS?

 

[hj]

wet vent

Unless you are using the term "wet vent" differently than the normal way, there is no reason for it to plug up any more than if it were not a wet vent. The only difference between the two is that the wet vent has more than one fixture opening on it, and they are separated by a few vertical inches. That does not make them more prone for stoppage. If fact, if anything, the added flow should keep them from clogging.

 

[almostdone]

my modified plan

applicable code: IPC

in NH, since this my residence, I am able to make this installation without a plumbing license as long as I pull permits and get the work inspected.

any chance that an inspector will approve this since there are two wet-vented fixtures and one dry vent that goes horizontal less than 6" above the flood level of the fixture.

 

[Terry]

AlmostDone,

It's a nice drawing.

You are plumbing this for IPC code?

Does the IPC allow revents below the flood level?

Does the IPC allow the trap for the lav to be below the floor?

I think most codes, since you are venting the toilet with a wye fitting,
would allow the lav, that is vertically wet vented over the shower, to be run in 2" between the shower tee and the lav tee.
The 2" would be a bigger pipe size than the lav would normally be with standard venting.
The 3" is fine too.