Sanity check on stack pipework please

[crispy_wafer]

Morning all,

 

I'm after a bit of a sanity check, or otherwise please, on the planning of an internal stack that will receive from the downstairs WC, and possibly the upstairs bathroom if my ideas pass muster.

 

Initially the drawings incorporated an SVP arrangement to look like this.  Pipework out the back, meaning I need to core hole and have pipework running externally like the picture.  So sitting at my desk I started procrastinating about whether I could do this better and avoid making holes in the brickwork, or not.  I think I can, but I either need a bit of reassurance, or telling to keep it simple and to plan.

 

I have a stack coming up in the downstairs WC Stud wall.  My bright idea, consisted of running this stack pipe up inside the wall then connecting a 45  3 branch to avoid the pozi joist then connect into the fall from the Toilet upstairs, I need to tap a 50 into this somewhere as well.  Once past the 45 I will run the 4 inch into a void behind a cupboard for an AAV.  Is it OK to have multiple bends and whatnot in the this (dry) section?  I will need to fix up the studding after I have carved it all up, I'm thinking I may face and join the sections of wall with ply/OSB to reinforce.

 

 

 

 

My plan to vent the stench, is to tee from the soil pipe as it runs to an IC and run a vent up the wall near the chimney breast

 

 

Would this plan seem OK, or am I going to be causing issues for myself.