Soil pipe connections through wall underground

[John Williamson]

Planning drainage for a new bathroom. Assuming that all the falls/gradients are correct is there anything wrong with this plan? Soil pipe from toilet goes through wall below the floor level so that I can connect a shower waste (wetroom so flush with floor). On the other side of the exterior wall is the soil pipe vent (with rodding access) and an inspection chamber where it joins the underground drain pipe at a 90 degree angle.

Been through all the regulations I can find and seems ok but maybe I am missing something?

 

[ShaunCorbs]

You could get the shower trap pulling when the toilet is flushed

 

[John Williamson]

You could get the shower trap pulling when the toilet is flushed

OK thanks. I've seen a fair few shower wastes connected to the toilet stack though. Doesn't the shower trap take care of this? Does this mean Building Control won't allow it? That it's bad practice or something else?

So shower waste should also go through the wall and connect to the soil pipe outside? What difference would this make to the pulling? It is because it would then be where the vent it?

 

[John Williamson]

Assuing by trap pulling you mean by siphoning. Sorry I am not great with the terms. So guessing using one of these on the stack would prevent that before the rest bend?

FloPlast Push-Fit 4-Boss Single Socket Waste Manifold Grey 110mm - https://www.NoLinkingToThis/p/floplast-push-fit-4-boss-single-socket-waste-manifold-grey-110mm/22367?tc=QB9&ds_kid=92700055281954505&ds_rl=1249404&gclid=CjwKCAjwgr6TBhAGEiwA3aVuIVC63irfqGFPNW4mWWD0VcKwH3zCq7l1JqojayUgQz2ciq4aqHBWcBoCnzYQAvD_BwE&gclsrc=aw.ds

 

[ShaunCorbs]

OK thanks. I've seen a fair few shower wastes connected to the toilet stack though. Doesn't the shower trap take care of this? Does this mean Building Control won't allow it? That it's bad practice or something else?

So shower waste should also go through the wall and connect to the soil pipe outside? What difference would this make to the pulling? It is because it would then be where the vent it?

Normally connected into the vent stack as well though

Either that or you need to carry a pipe through so you can fit a auto vent

And yes siphoning the trap out

 

[John Williamson]

Normally connected into the vent stack as well though

Either that or you need to carry a pipe through so you can fit a auto vent

And yes siphoning the trap out

Thanks so much. So something like this with the shower/sink waste through the wall connected to the vertical vent pipe?

 

[ShaunCorbs]

Yes or as your first drawing but with an additional aav on the end of the run above ground