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mikect05 · Nov 19, 2011, 09:05 AM

Hi, I am plumbing in a lav and a bathtub both are stubbed at 1.5" I increased both to 2" hoping to avoid clogs due to girls with long hair in our family.
My question is can my tub be wet vented by the lavs 1.5" vent? The distance will be about 4' from the tub trap to the lav's vent.
Thanks guys

massplumber2008 · Nov 19, 2011, 02:17 PM

Hi Mike

If piped correctly, you can wet vent the tub using the sink drain/vent, but technically, it needs to be a 2" drain/vent all the way until it connects to another 2" vent or penetrates the roof by itself.

Mark

mikect05 · Nov 20, 2011, 06:47 AM

Once again thank you Mark. I cannot use a 2" however because the wall is old and is 2x3 construction and I need to have the drain actually go through one of the studs. I will vent the bathtub seperately. So it is okay to increase both drains to 2" correct?
If you don't mind I would like to dry fit the fittings and submit a picture for your review.
Thanks again!!

massplumber2008 · Nov 20, 2011, 08:05 AM

Plumbing code will not allow anyone to run 1.5" pipe and then increase it to 2"... just not how it gets done!

However, if you have a 3" or 2" pipe and you want to run 2" to the fixtures then that is perfectly fine.

I am glad to review a dry fit. I am back on later tonight around 6:00ish.

speedball1 · Nov 20, 2011, 09:51 AM

Hey Mike,
If you "dryfit" your PVC fittings ben awarew that the female hubs are tapered slightly and will bind tightly if you drive the fittings home. Good luck, Tom

mikect05 · Nov 20, 2011, 09:57 AM

Okay so I can either tie these two drains together using a Y and then tie that into the main 3" drain, or I will just tie them into the main seperately. If I tie them together first do I keep it 1.5"?

I would much rather have my tub drain be 2" but the drain and overflow for this tub is 1.5 brass.

speedball1 · Nov 20, 2011, 10:12 AM

I would much rather have my tub drain be 2" but the drain and overflow for this tub is 1.5 brass.

Which should connect to a 2" trap and drain line.
Cheers, Tom

mikect05 · Nov 22, 2011, 09:03 AM

Hey Tom, glad to see you are back. Sorry I am not sure if you are saying that I can connect the 1.5 drain to 2" trap and drain line, or that I cannot do that.

speedball1 · Nov 22, 2011, 09:22 AM

Hi Mike,
My house was hit with a surge that fried my computer and monitor so I had to replace them. It took a while so I was off line for a while.

I would much rather have my tub drain be 2" but the drain and overflow for this tub is 1.5 brass.

If this is your concern then put your mind at rest.
A 2" trap will come with a white nylon bushing that will accept a 1 1/2" pipe. More questions? I'm as close as a click. Tom

mikect05 · Nov 22, 2011, 02:10 PM

How does this look?

mikect05 · Nov 22, 2011, 02:11 PM

How does this look?

Sorry for the multiple posts, having trouble uploading the picture and making it bigger, hopefully have it now.

speedball1 · Nov 22, 2011, 04:34 PM

Hey Mike,
If you posted a attachment it didn't make it. Try again. Cheers, Tom

mikect05 · Nov 22, 2011, 07:15 PM

Okay trying this again... Thx

http://i120.photobucket.com/albums/o...dlavdrain1.png

the only thing I left out here is I will put a 2x2x 1.5 tee after trap for the vent to go straight up.
So does that look good? Thanks

massplumber2008 · Nov 23, 2011, 07:32 AM

Hi Mike

You don't need the stack going up like you have... see my picture. That is, unless that stack is existing? If it is, then I need to know if it is connected to the downstairs bathroom?? Let me know, OK?

Otherwise, as drawn below, you should only need the one 2" vent to vent both the tub and the sink, right? I understand your wall isn't deep enough, so if you must reduce to 1.5" pipe then do so, but if a permit was pulled, the inspector would just tell you to "pad the wall out an inch and put up new drywall" to keep that vent 2"...;)

Note, that the vent needs to roll above the centerline of the tub drain to be a vent...even if it is a wet vent.

Send a 2" drain to the lavatory if you can as this at least gets you as close to code as you can get, again, considering your wall isn't deep enough for a 2" drain/vent pipe.

I didn't understand this--->>> "the only thing I left out here is I will put a 2x2x 1.5 tee after trap for the vent to go straight up"...? Here, the tub vent acts as the lavatory drain and the lavatory vent...it's what makes the tub "wet vented" by the sink, so you don't need the additional 2x2x1.5" tee fitting, right?

Back to you...

speedball1 · Nov 23, 2011, 08:09 AM

Mark makes valid points. I like his layout much better. Since you won't be venting the lavatory from the trap will you be installing a "S" trap on the lav? Regards, bTom

mikect05 · Nov 23, 2011, 11:47 AM

Thanks Mark. Really appreciate your help.
No the stack is not exsisting there. So I will go with your design. I just have to support the wall where the 2" pipe will go through it. I will keep you posted as I do the work.

Hey guys can you tell me if this looks okay? this is the trap for the bath and the hole is for the 2" lav to come down angle around and join into the Y there. The lav drain runs up to the 2" P-trap.

mikect05 · Nov 25, 2011, 11:25 AM

They are just dry fitted for now to show you, waiting your opinions before glueing them together.

massplumber2008 · Nov 25, 2011, 12:21 PM

Hi Mike

Cement 'er up... looks just fine!

If possible, connect a TEST TEE (see image) cleanout somewhere either after or before the tub wye, OK?

Mark

PS: The image shows a black ABS cleanout... obviously, you want PVC.

mygirlsdad77 · Nov 25, 2011, 04:23 PM

Mark, how is that fine. Not only is there a running trap, but also an s trap. Vent is nill and void here. Not often, if ever do I disagree, but this wouldn't pass anywhere. Take a closer look.

I would suggest using a pvc waste and overflow so you can use some 45s on the overflow to get past that joist. Then drop straight into the trap, (as Mark drew it up perfectly). The sink drain(whick will also serve as the tub vent) will drop into the wye like you have the tub drain dropping the wye in your pic. Hope that makes sense. And I hope you haven't glued it yet.

massplumber2008 · Nov 26, 2011, 05:51 AM

Hi Lee...

It looks like he used an ABOVE THE FLOOR ROUGH IN tub waste and overflow assembly. Here, these are rare, but when used I notice that most inspectors allow them in place of cutting out/heading off joists (check out the double joist in his picture where the tub waste would be if he used a regular tub waste), but I certainly see why you mentioned what you did... ;)

I didn't see an alternative, besides heading off the joist... unless he added an individual vent, of course, but as I've used a few of these above the floor rough ins over the years, this seemed OK.

In terms of the STRAP... I am guessing you are talking about the sink? That should be vented with a 2" vent here so it should be a PTRAP going in. If not, and you are talking about the tub trap then yeah, he certainly could lose the street fitting coming out of the wye and roll that wye flat... WOULD DEFINITELY BE A BETTER JOB, FOR SURE!!

Back to you...