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Groundfloor waste/soil layout below slab in barn conversion

Postby JBISHOP1987 » Mon Jun 28, 2021 1:10 pm


I'm trying to design and simplify the ground floor waste layout on a barn conversion. The groundfloor will be based on a concrete slab so all pipework will be permanent and it is essential it's correct and easily unblocked if required.

The ground floor has two ensuites, a WC and a utility room.

I was planning on running a common pipe across the width (right to left on the picture) of property and have each ensuite link into the pipe via a Stub Stack, into a rest bend and then a joining 45' junction.

The common drain would have an external AAV with rodding access (far right on picture).

I have no plumbing/drainage experience, I've tried to read up as much as I can and ultimately will probably have the groundworks guys do all the work. I'm just hoping to pre-empt any issues and have a bulletproof setup. It's also quite interesting to learn new things. If there's a better solution I'm definitely keen to hear it.

RED LINES indicate the common drain.
RED DOTS Stub Stack

The shower, due to a low profile shower tray was going to link to the Drain directly (via a low profile trap).

I think it might be possible to coincide two of the stub stacks but my uneducated concern is the two toilets would meet at the same level 90' apart, (WC and Ensuite).

I was also concerned about potential siphonage when using stub stack too?

Thoughts / ideas solutions are much appreciated
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Simply Build It

Postby stoneyboy » Tue Jun 29, 2021 8:53 pm

Hi jbishop1987
How about locating the main drain run next to the bottom wall and drop straight into it as required. This eliminates 4 Y junctions. You should have an external stench stack at the right end going above roof level with an open end.
Regards S
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