Drain lines below underbelly

[Maineman]

Installing a new bathroom with relocated tub, toilet and sink. Also installing all new drain pipes. Currently the 1 1/2" drain pipes from tub and sink are above the underbelly and connect to the 3" pipe near the tiolet. The 3" pipe drops below the underbelly from under the toilet. Would be a lot easier if I could make all my waste line connections below the underbelly. I figure it will be OK as these pipes have no standing water in them. Sink trap is under the vanity, tub trap will be above the underbelly.

Thanks,

Tom

[tnt17]

I am in S.C, and my connections are all below the underbelly. Had it set up last year so this is recent at least. Only thing i'd worry about up north or in 'super' cold states would be freezing....uggh, freezing waste, is that possible?

[Greg]

Tom, On paper you are right, there SHOULD be nothing in the pipe to freeze, but we both know better than that. A leaky toilet or dripping faucet can change everything.
If possible I would keep them above the insulation. Greg

[Robert]

Yep, I second Greg on this, epecially in northern winter temps.

A leaky faucet or toilet and that drain will freeze quick in winter.


Take care and best wishes,
Robert