Plumbing options

Old 08-06-19, 10:21 AM
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Plumbing options

Hi everyone. We are looking for advice on some plumbing options for our kitchen renovation.

The attached picture shows the outer wall of our kitchen (Green). We hope to demo this entire wall to create a bar/island countertop area. We have an issue with the wall by the thermostat/closet. The plumbing from the upstairs bathroom runs directly through that wall (Red).

What are everyone's thoughts on redirecting the waste line down a different wall (i.e the wall directly behind the wall to be demo'd? - Blue)

Appreciate your input and advice.

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Old 08-06-19, 11:02 AM
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It is possible to relocate the drain stack but it depends on the location of the bathroom upstairs and the thickness of the floor (joist height between floors). The first issue will be elevation. There must be enough height in the floor for the drain pipe to have the proper fall and make it over to the blue line.

The main drain in the floor above is either 3 1/2" or 4 1/2" outside diameter. Because of the fittings it probably starts a couple inches below floor level. So the bottom of the pipe at the beginning is probably down about 6". Then it must slope downhill at least 1/4" per foot so for every four feet away the pipe gets 1" closer to the ceiling below.

The next issue is what are your floor joists? You can't just cut or bore great big holes through your floor joists willy nilly. Hopefully you have nice tall open scissor trusses as that will making re-routing the drain line easy. If you have traditional lumber joists then you are much more limited in your ability to have the drain line cross joists.

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