Vent solutions for LONG distance drains

[Rocknice21]

Hello everyone,

I have a bit of a problem. How do you drain a whirlpool tub that has a drain that is 4 ft from any wall??

Can I just run a vent off of my main horizontal run? How far away can that be from the drain?

I tried to draw my plan the best I could... The waste from the tub has to go 4-4.5 ft before "finding" a vent. The toilet has the same, about 4 ft. Will this work?? Would increasing the size of the vent assist this?

Thanks!

-Ryan

 

[Leejosepho]

The issue is to make it impossible for a drain line that is full of water to siphon the water from the trap after the tub goes empty. Personally, I would probably either move the trap closer to (or even next to) the area of the vent so no siphon could ever develop, or I would use a pipe larger than the trap to go from the trap to the area of the vent. A trap dumping into a larger line cannot be siphoned by that larger line because the trap cannot let enough water through to completely fill the pipe, and that same fact means your toilet should also be okay since its opening (just abover the floor) is less than 3". A professional plumber might suggest something different here, but my toilet (4' from the stack) and washing machine (20' feet from the trap) are plumbed like I have mentioned and I never have any vent or trap problems. But if you must deal with an inspector, you might have to keep the tub trap directly under the tub drain and simply use a larger-size pipe to get to the area of the vent.

 

[Sponsor]

 

[Krow]

check your local codes, but in my area , we are allowed to install back vents. (A tee placed on its back and offeset the vent below the floor and connect above the flood level rim of the highest fixture

 

[plumb.bob.down]

You can go up to 5' away from the trap for a vent, that is, if the trap is 2".

That's the Kentucky code anyhow. .

Our Ky code is pretty strict. No flat venting, 3" minimum vent through roof, no stacking fixture drains into a main, etc. .

 

[Rocknice21]

So if I move my 2"/3" adapter coupling upstream of where my tub drain ties in, it will be able to vent properly? Is this what is called a "wet" vent?

leejosepho
Many, many thanks for explaining the concept behind the vent function!

I live in West Virginia, out of city limits, and am not governed by any codes.

So would I be able to use a sanitary tee instead of a wye to run my 2" vent off of the 3" horizontal run?

 

[Jadnashua]

Your county may not require an inspection and permit, but I'd bet the state has adopted a set of codes that apply to any placde without a local enforcement authority. Now, who would hit you up for not following those codes is another thing altogether.

 

[plumb.bob.down]

Not visualizing what you're talking about rocknice21.

A wet vent occurs when you use the vertical vent of a fixture from i.e. "1st floor" as a fixture drain for a fixture on "2nd floor".

 

[Redwood]

A wet vent would be if you had say a lav sink that was plumbed a certain way that emptied into the tub drain line. The tub can be vented by the lav sink by its drain which is wet. Hence a wet vent.

Fixtures cannot be wet vented by different floors.

 

[Leejosepho]

So would I be able to use a sanitary tee instead of a wye to run my 2" vent off of the 3" horizontal run?

If you are talking about something like what Krow has sketched, a wye and a 45 would make a gentler turn ... and that is how I usually try to do things. However, there are certain "rules" for orientations of fittings and I do not know which or what might actually be best in that specific situation.

 

[Master Plumber Mark]

Why Not Just An Aav Vent??

I cant figure ou th the drawing very well but


why dont you just put an AAV vent under the
Whilrpool tub with access to it???

we see that a lot around here on many whirlpools,
and even if it is not necessary, it still cant hurt.....



you could run a 2 inch vent to the attic, I would just put the vent above where the toilet
ties into the line, not after the toilet... and that would work as a vnet for the
whirlpool tub...

 

[Rocknice21]

Check this drawing out. I had to split it into two files so sorry if it's tough to read. Will this venting work? If I move my vent upstream of the toilet, I will have to drill through 1 or 2 joists, and I can't run it less than 45 degrees from horizontal, right??

 

[Leejosepho]

Are the toilet and tub draining into the same horizontal line?

Or, what other fixture or intersection is upstream or downstream of the tub?

It looks to me like your vent for the toilet is optional as far as venting the toilet is concerned since it is so close to the main stack/vent.

 

[Rocknice21]

Thanks for your continued help!

I'm wanting to tackle this job this weekend!

Yes, the toilet and tub are both emptying into the same horizontal run. Upstream of the tub, there is a shower and two sinks emptying into that run as well. Plumbing and venting those was no sweat though.

The toilet has about a 4 ft horizontal run from the flange to the main run, then takes a 90 degree turn to empty into the main 3" horizontal. There are about 5 ft between where the toilet ties in and the mainstack. That makes the toilet about 9 ft from the stack.

The tub comes into the main line about 3 1/2 ft upstream of the toilet, so it is about 8 1/2 ft from the stack.

Thanks again! The bottom section view (in the bottom drawing) of the toilet run is a view from the lines A - A'

Ryan

 

[Rocknice21]

so how would you all vent the toilet and tub?? (in the room on the right) The blue lines represent 2" runs of horizontal drain, and the red lines represent 3" runs. Look at my other drawings??

Is my overall plan flawed? Do the toilet and tub even need to have a vent before the stack??

I have the two sinks and shower vented right after the trap (up through their adjacent interior walls)... no problemo there.

My floor joists run top to bottom, 16" o.c. by the way.

Thanks!

-r

 

[Leejosepho]

Yes, the toilet and tub are both emptying into the same horizontal run. Upstream of the tub, there is a shower and two sinks emptying into that run as well. Plumbing and venting those was no sweat ...

Do the toilet and tub even need to have a vent before the stack??

I could be wrong, but I do believe that 3" line is already well-vented. The tub and toilet going into a 3" line are not likely to bother each other, and neither will they likely bother the vented fixtures upstream. Flushing and/or draining all the fixtures on that line at once might strain the shower and sink vents a bit, but what you are doing sounds fine to me ... just keep in mind that I am not a pro.