Plumbing questions on drains

[Wayne Whitney]

Hello,

On my bathroom remodel project, I'm trying to figure out the best course for my building drain, for ease of tying in my branch drains and connecting to the building sewer. A couple questions came up:

1) If I want to transition a drain from vertical to horizontal, and I have enough space/altitude, which is better, a long turn 90, or two 45s with a short section of pipe in between?

2) If I have a vertical drain line that is offset from a horizontal drain I want to tie into, I could use a long turn 90 to go horizontal, and then use a WYE (flat) to join the horizontal drains. Is it better to roll the WYE inlet up and use a shallower bend on the vertical drain (e.g. a 60 or a 45 + a 22.5)? That seems trickier to line up.

3) If a horizontal drain line goes vertical, and then goes horizontal again, is there any restriction on the net angle in the plane the drain has turned? For example, if I stack two long turn 90s, can I have an arbitrary angle between the horizontal inlet and the horizontal outlet (as seen from above)?

Thanks, Wayne

[lowspauld]

Wayne Whitney wrote in news: [e-mail]:

Up to you, 45's are easier to snake and less prone to plugging. I avoid the 90's but I still fall for the light bulb deals at garage sales.

[Speedy Jim]

Either way. You can also use a 45 and a street 45 together; This gives a bit more flexibility where needed.

I would roll the WYE and use a 45; much less prone to clogging than laid flat.

Not sure I understand, but remember that EL's are not a true 90. They are slightly more than 90 deg to provide 1/4" per foot of slope. Jim

[Wayne Whitney]

Hello Jim,

Thanks for the answers as always!

Someone else suggested that two 45s, with a short pipe in between, would be easier to snake and less prone to clog. Does it make a big difference? I imagine that the sweep of a 45 + a street 45 is equal to the sweep of the LT90, when the 45s are in the same plane.

Well, if I roll the WYE exactly 45 degrees above horizontal, then I need a 60 degree bend to get the branch inlet to vertical. That was a tricky calculation I did with a nice simple answer.

Right, good point. Are 45s true 45s?

My question about the LT90's is this: suppose I have two horizontal drain lines, one is two feet above the other, and they are not parallel: viewed from above, there could be any angle from 0 to 90 degrees between them, or taking into account the direction of flow, any angle from 0 to 180 degrees between them. Now I could connect the upper one to the lower one with two LT90's: the first one takes the upper line from horizontal to vertical, and the second one takes the vertical back to horizontal (but two feet lower).

Could I legitimately reverse the direction of flow this way (180 degrees) as seen from above, or is there a restriction on how much that angle can be, when I only fall two feet? I imagine that if I had a lot of fall, say one story, there would be no restriction. What would be the minimum fall needed to have no restriction?

Thanks, Wayne

[Speedy Jim]

Yep, 2 45's equal a LT90.

OK

No, they have the slope built in too.

You can get into trouble here due to the fact that the EL's are (slightly) more than 90 degrees. (Picturing this stuff gives me a headache!) You can fudge it using plastic pipe and fittings because they are rather forgiving, but in some situations it will affect how they go together.