Okay to use a WYE tilted 45 degrees from horizontal?

Would the WYE installed at 45 degree be to code? (See picture below)

You can't do that.

Y

And WHY can't he use a "Y"? There is absolutely no difference between that and a sanitary tee in a vertical line. The question might be why it is being done that way, however.

hj said:

And WHY can't he use a "Y"? There is absolutely no difference between that and a sanitary tee in a vertical line. The question might be why it is being done that way, however.

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There is a difference and the difference is that the wye in this position is going to create hydraulic jump from the sink which is going to interfere with the toilets operation.

This design would go against "good piping practice" and would never pass inspection (or atleast it shouldn't).

Here is that another way I was going to route the pipes, but this one involves putting a hole through the floor joists which I was trying to avoid by coming underneath then through an existing soffit. I imagine there are other ways I can accomplish this, so I will keep working at it. However, do I have the same problem with the wye on it's back? I thought this configuration was typical.

mjsmith0 said:

Here is that another way I was going to route the pipes, but this one involves putting a hole through the floor joists which I was trying to avoid by coming underneath then through an existing soffit. I imagine there are other ways I can accomplish this, so I will keep working at it. However, do I have the same problem with the wye on it's back? I thought this configuration was typical.

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The 2nd example is the prefered way to do it. You are right they both sort of do the same thing with the hydraulic jump (I never thought of it that way!).

The 1st example is just a goofy way to run a drain and no one ever does it that way. I looked through my code book to find something that would prohibit the 1st design but I couldn't find anything. So I guess it would possibly be acceptable under code but I think your inspector would turn you down.

I have been doing this plumbing thing for a while now and I have seen lots and lots of goofy things but I have never seen a wye installed in this fashion.

What is above this bathroom draining into the stack going up?

Thanks, I think I will try to stay away from the goofy stuff! A washing machine drains above the W/C, and a shower drains above that with a vent coming out the top of the stack.

I figured a different way to route the drain from the W/C & Lavatory, though I will need to make the soffit a little longer than the one that is there now. Everything get a lot more straight forward if I just drill though the floor joists, but I'm just a little nervous about doing that if I can find another way.

mjsmith0 said:

Thanks, I think I will try to stay away from the goofy stuff! A washing machine drains above the W/C, and a shower drains above that with a vent coming out the top of the stack.

I figured a different way to route the drain from the W/C & Lavatory, though I will need to make the soffit a little longer than the one that is there now. Everything get a lot more straight forward if I just drill though the floor joists, but I'm just a little nervous about doing that if I can find another way.

Click to expand...

That looks much better!

hj said:

And WHY can't he use a "Y"? There is absolutely no difference between that and a sanitary tee in a vertical line. The question might be why it is being done that way, however.

Click to expand...

I agree with hj, either way you are coming in on a 45 and landing on a horizontal , in fact on the first way a lot of the discharge from lav will shoot down the 45 out of the way. Who ever drew the red lines made the flow look worse on the first one when actually they will be the same. I wouldnt install it that way though because might have to argue with inspector.