Home>Discussions>PLUMBING>need advises: plan to add a new 2nd FL bathroom, but main stack is 30' away...
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sunwave
need advises: plan to add a new 2nd FL bathroom, but main stack is 30' away...
sunwave

need advises: plan to add a new 2nd FL bathroom, but main stack is 30' away...

Hi, all, any advise is appreciated.
Do I just use a long 3" pvc to connect the main stack? or dig out the basement ground to make a new stack?
If I choose the long pvc option, slope drop would be 1/8" per foot times 30 feet= 6.6', right?

ed21
Re: need advises: plan to add a new 2nd FL bathroom, but main stack is 30' away...
ed21

1/8"/ft for 30' run is a 3 3/4" drop

MLB Construction
Re: need advises: plan to add a new 2nd FL bathroom, but main stack is 30' away...
MLB Construction

and you'll have to install a new vent through the roof above the new bathroom

dj1
Re: need advises: plan to add a new 2nd FL bathroom, but main stack is 30' away...
dj1

Your building inspector will disapprove such a long horizontal run without a vent.

The simple plumbing reason: it will "break the seal" between room pressure and vent pressure.

Solution: run a vent from the new bathroom through the roof.

sunwave
Re: need advises: plan to add a new 2nd FL bathroom, but main stack is 30' away...
sunwave
ed21 wrote:

1/8"/ft for 30' run is a 3 3/4" drop

lol, I'm terrible with math! Thank you for the calculation.

sunwave
Re: need advises: plan to add a new 2nd FL bathroom, but main stack is 30' away...
sunwave

New vent is easy, thank you all!

bill
Re: need advises: plan to add a new 2nd FL bathroom, but main stack is 30' away...
bill

Why are you putting the bathroom 30 feet away from the plumbing stack? Normally we cluster plumbing fixtures together. Could you put the new bathroom on top of the existing bathroom on the 1 st floor?

dj1
Re: need advises: plan to add a new 2nd FL bathroom, but main stack is 30' away...
dj1
bill shack wrote:

Why are you putting the bathroom 30 feet away from the plumbing stack? Normally we cluster plumbing fixtures together. Could you put the new bathroom on top of the existing bathroom on the 1 st floor?

Could be impossible to do, we just don't know. I've seen additions that don't really fit the way you expected, hoped or planned.

Mastercarpentry
Re: need advises: plan to add a new 2nd FL bathroom, but main stack is 30' away...
Mastercarpentry

Sometimes the only other option is worse, such as breaking up concrete floors and running another main line to the sewer outside of the house. Long for a horizontal run, but if it's all you can do it should be OK.

Phil

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