Rishard

If this is the case then the aav doesn’t need to be at the furthest point? Is the basin gurgling fear mostly avoided by using the AS traps?

So would you recommend using 2 x 2” aav’s at the furthest point nearer the bog in the ensuite and not bother with an aav in the family bathroom?

Understood. Yes this drops down from first floor level to ground level and out to the inspection chamber. The family bathroom joins this same 110 stack. Would I need an aav on the family bathroom side too?

I’ve set up the 110mm pipe tote far end of the ensuite. It has a gradual fall of 55mm over the 5.6m distance. I will connect a bog to it and test before it’s boarded over but I feel pretty confident. I will be connecting the shower and basin to this 110mm in due course. I was working on a job recently where a plumber suggested using a small 2” aav if I wanted to bring it up a stud wall. I could create a small removable panel where this could be accessed. @Nickfromwales Have you heard of doing this before? My bog outlet drops straight down into my 110mm so wouldn’t require boxing in the room to hide a regular aav.

What is this other thread? Regarding a brilliant quote / method of obtaining BUS grant ect? Cheers

Also interested in this micro cement flooring. Did you go with it in the end?

Are you able to share a cost for this? Would love to know. 🙏

It is a straight run, apart from a 45° where it joins into the stack. I’m happy to make it the designated site bog while the build progresses. That should put it through its paces. I did think about having a high level traditional cistern. Would this add any extra umphh to it? the storage solution is also a good idea. I’ve done plenty of boxes out skirtingboard plinths in the past for customers. Feels like a bit of an after thought, a cupboard sounds more intentional.

If I was to run the en-suite w/c the full distance it would need to travel 5.6m to get to the stack. I’ve got 50mm at the very most for the fall. Do you think that’s possible? Would be great if it was… I’ll have a building inspector but if it’s the same guy, I doubt they will give it a seconds glance. More for my own piece of mind. He didn’t care a dot about the tons of mesh Il lapped to specific distances and tied beautifully all to the spec of my engineer. More interested in talking about how crap the company he works for is. I’ll try some of that banding and mating. Looks the business.

I’m going for 12.5mm per m. This works to the original plan as sadly I only have 50mm adjustment within the web of the joists. 110mm pipe inbetween the 160mm webs. Based on this lack of fall to move the en-suite w/c to the new location using the floor void to get the fall I may have to settle with its original location. Alternative option would be to exit the w/c waste out the wall and create a new stack to serve this externally on the house. Not a fan of this. or box in above floor level in the en-suite . Also not much of a fan of this. Should have gone for the larger joists… ah well. Maybe next time.

Ok that makes sense. I think I’ll try dog leg the stack so it comes up in the bathroom using 2 x 45° bends. Just enough offset to get through a 140mm block wall and come up on the otherside. It’s doesn’t look too upsetting. My en-suite w/c is 2.8m from the stack so I can just get the fall within my joist webs. Do you think if I wanted to move my w/c to where the basin Is in the en-suite. Could I do a stub stack in the corner where the w/c is currently located and gain the fall above floor level in boxing? Because of where the joist webs are my 110mm pipe is about 200mm from the wall. A swept bend might be needed if I was to do the stub stack option. I see in the regs that it should be avoided where possible but can be used if large radius bends or 2x45° are used. Would be using an aav.

Great. This makes much more sense than trying to run multiple individual wastes back to the stack. I want them all to be ran in the floor void to keep the rooms as clear as possible. Would I be right in thinking all these bends / connections want to be solvent welded connections?

I agree, main soil stack can be dog legged to come up in the bathroom which makes sense. Are you saying the 2 toilets should have their own 110mm run rather than joining together before joining the stack. Once the en-suite toilet waste is in the joists, is it ok to join on to this run with say the shower waste? Would I use a strap boss onto the 110 or is there a better method?

Hello, just scouring the web / forum for similar ideas relating to first floor waste runs. I’m trying to work out the best way to route my waste pipes back to my stack. Is it best to try group the en-suite shower/basin/w/c into one 110mm pipe and back to the stack, or keep w/c separate from the basin and shower? From my research, these could step up to 50mm pipe from the basin/shower and back to the stack. OR Should I be trying to group say the w/c from the en-suite and the bathroom on the same 110mm run to the stack? Keeping the en-suite basin / shower on one 50mm run and do the same for the bathroom? I have posijoists which I can route most of these runs in. The w/c near my stack could go through the wall if beneficial. I’d also take some advice on good way to fix all this pipework to the posi joists. I thought about using some rips of ply to use as a side wall which I could clip / fix pipes to (on a fall) but if there are any other good bracket fixings people have used which would take up less space I’d be interested to know. Has anyone used much dampening on the larger soil pipes to reduce noise? Just a thought as the stack is currently coming up in the corner of a bedroom. This could be adjusted to come up in the bathroom if it makes more sense. Thanks for any insights. Stack highlighted red

@Russell griffiths what roof system / covering is that? Looks brilliant.