Oz07

min 1 in 80 with 4" pipe and at least a loo plumbed into it i think. I'd be wary of going any less on 4" pipe. Has to be steeper if it's not getting as much flow down.

There aren't maximum falls anymore as I understand it. PVC pipe did away with that

Just do plan A I bet the BCO approves. Plan B looks messy to me

Ive encased in concrete before but not sure its nessecary. See so many sites without any protection and nothing ever happens. I knew lorries would be going over so played it safe. See how many reduce dig for new driveways exposes drains that work just fine without protection. I think its probably more important to have a tight trench with minimum pea gravel needed to comply if under a driveway.

Eliminate the 45 bend after the y branch just position the y so you are coming straight up with a 90 possibly with a short straight stub of pipe between them

That's good to my eyes. If possible where that 110mm pipe comes up for the basin in the far corner can you build an accessible boxing then you could have an access plug into your pipework and rodding access in the unlikely event it was to block. Otherwise you can keep taking the pipe out thru the building on that opposite corner. Will it be high enough to clear the trench concrete by then? Then put external rodding eye. There is an argument to say keep the shower on its own separate run into the manhole then you have no y branch down stream from toilet. I think you'll be fine though. You could even cock the y junction a bit so its not flat and the branch to the shower is sticking up a bit, then immediately put a 15deg fitting on to take the pipe back level. Should give you a small stepped invert. If you've seen a flush invert manhole its really no different to a flat junction and the man holes don't just spontaneously block up. Where is the resident plumber @Nickfromwales?

Maybe just one run and eliminate the bend before the main run exits the house. It'll be easier to do because you can align with basin instead of wc

I don't think you will find a certified 45mm pair maker but you can Google it. I doubt building control are switched on enough to realise a pair maker isn't fire proof. Fire doors as doubles usually just meet in the middle with 3mm gap and intumescent strip in 1 face. You can do this, get sign off, then if 3mm gap really bothers you reduce doors down to allow pair maker

Rather than having your wc coming into the top of the run like that put a y junction in on flat below the slab then bring a 90 up thru the floor. The poo will slide down the pipe better then rather than falling into the top and the water running away from the solids. It will prob work ok your way but I'd rather my way. You have a rodding access upstream so the y under the floor could be accessed if ever blocked.

Bloody hell you seem an expert yourself 🤣

Always a bit dubious of posts like this. Are they copy paste jobs?

Something like this. You can take thru the opposite wall put a 45 on then rodding eye at ground level. I would say be better if wc comes in with a 90 bend to the invert rather than a swept 90 poking upwards so put a horizontal y in. Make the run inline with basin point and join wc into it with a y. If you cant take shower drain out right where it is on external wall then join with a y just before the drains pass thru wall. Also prob take shower drain out with rodding access. I'm just thinking on my feet. There are probably better ways

Stop having 90s under your slab. Just get the straightest runs you can

It definitely does. I had it in last place and carpet fitter fitted a threshold hard up to it. Expanded in middle of the run in hot weather

Seen a plumber i know today we got talking about that boiler. Also costs of the install Whats some rough costs supply and fix for That combi System boiler and uvc Ashp and uvc He was telling me how expensive some of the heat pumps can be.

Is the game up with these new regs and this principle designer lark with self build? It certainly sounds like it to me. Too many office wallahs trying to impede the process. I mean we're building houses its not rocket science. No wonder the industry is on its arse.

I managed on my own but was using 1 or 1.5 m wide, with 2 people it should be easier. I stapled mine up at start, ran it out 12m then stapled and cut off. Probably stapled it a few times on occasional ceiling chords as I ran it out. Taped over staples as above. I did 2 lots of counter battens and piloted and screwed the ones which punctured the membrane. Used some good 6x150mm screws at first but then I was using 70mm deep battens x2 to get 140mm total void. Only tip I can think of is with any decent sized penetrations (ie mvhr exhaust and intake) I traced round then cut a smaller hole than the pipe by about 10mm. Then when pushing the pipe thru this stretched the membrane and already gave a pretty good seal. Id probably then try to get some proper pre formed tape for holes. I just used loads of cuts of the airtightness tape going lengthways till the circumference of the pipe was done.

dewalt titanium one of the more expensive models they do but been good for me for years.

https://inews.co.uk/news/politics/tax-building-scrap-homes-target-3978843?ico=most_popular Most waste on a newbuild building site is pretty easy to segregate. If you're careful you don't need many mixed waste skips.

Just been listening to some guy on x saying build cost at £3000 p/m2 by the time you add land and builders profit sale price around £6000 p/m2. They must be talking London or south east at those numbers surely? Sales prices here in Midlands around £3000 per m2

It won't be his problem then or his insurer refusing to pay out. You can't allow for every eventuality. Wouldn't the new couple need hetas or bc to upgrade stove? Then hetas fitter would flag up the issues. You need gas safe when changing a boiler.

That was my conclusion too. Although I think after 10 years you would be insurable and sellable as wouldn't be a new build.

Alot of times the pan doesn't even need mechanically fixing down. I think resident plumber expert @Nickfromwales was just saying the other week he uses ct1 to stick his down. I didn't fix mine in last place. One was back to wall and stuck to wall, other was close coupled but fine stuck ontop of floating floor

My God find something better to do with your time

Do you guys have photos of yours in? How do you maintain air tightness where flue passes thru wall?