Nickfromwales

Oh dear...….. I wonder where he thought the hot water was coming from, if he thought that was for UFH

Yup. Or if not, can you take it to a drain by dropping down the outside wall? If the drains are combined ( foul and rain ) then you could go and tap into the downpipe with a snow box.

You've never lived...…

Glad I couldn’t afford it ?

Yup. OCD / ADHD whatever. Brain decides to start going through lists and the frame has to get up with it. My oldest is the same. I wonder where he gets it from ?? One of those is regular, and the other ( more expensive ) is flexible. If it’s UFH or porcelain tiles then it’s flexible every time. Regular only if it’s a dumb slab and ceramic tiles.

Shouldn't that be 'I think I might have to grout'? Still not sure what gout is, but hopefully massively reducing my intake of beer and not wolfing steaks down will remove some risk.

Another option to extend the site of an AAV is to reduce from the 110mm to 2 x 50mm runs, or 4 x 32mm runs and route the groups of smaller bore pipes where the 110mm cannot be run. Create the opposite adaptation at the AAV end to get back to 110mm and fit the 110mm AAV there. You only need a 34 mm cavity for that.

If you have vented the TP then no need whatsoever for rising vents to atmosphere. I suspect your designer has done that because they would look terrible if they stopped a metre up from the branch and had AAV's on them. As to burying in the concrete core, I imagine that would require your concrete section to be thicker there to compensate, unless, possibly, you went to galvanised steel with a decent thickness wall. You can reduce the size of the rising SVP to 80mm if there is only one WC connected, so you'd likely need to do a drop for each WC to get the smaller diameter, ( if that would help swing it with the SE ). Not something we can answer here I'm afraid. As for specifying alternate routes for the stacks, its all a bit hopeless without sectional drawings to see what obstacles lay in the way of other routes. All academic without those. Make sure the bath run is done in 50mm not 40mm as the run is excessively long for a bath to discharge. With 50mm you'll get an air break, with 40 probably not. Can be mitigated against by carrying the 40mm past the bath trap and up to the attic and fitting a 50mm AAV. Also, using the 50mm would mean you could connect all the baths / showers / basins into one single run, subject to fitting an AAV at the end of the run as aforementioned. An anti-syphon trap on the basin would be preferable with the smaller bore SVP's should you end up going that route.

Tape the ends of the pipes with cheap electricians insulating tape to stop any crap getting into the pipes as you work them through the build. The outside diameter of the pipe is critical for getting the o-ring in the fittings to seal well, so if you drag the pipe and create a linear scratch along its length expect to get problems later on in the second fix. The o-ring squeezes onto the outside, so water would happily track along any linear imperfection. I cringe when I see plumbers yanking it through tight holes in timber joists.

@joe90 On a dry dusty floor I always mop the whole floor first with 25/75 flexi primer/water until saturated. That'll dry more or less in front of you, and then you're good to lay. After mixing up ( standard set if its a big area and I'm on my own ) I have a bucket of 50/50 and a sponge and dampen the area I am about to lay. Haven't lost a patient yet, and have never used SBR. A lot of people, mostly plasterers, swear by SBR, ( I think they use it in their tea / coffee instead of milk TBH ) but if there is a product for one job and a product for another, then buy the one that says so on the tin AFAIC . I've used Mapei by the bucket load so no issues there, and many others such as Bal ( expensive ), Ultra ( my first choice as I've used mountains of it with fantastic results ), Kera, Granfix, and other 'knowns', but the only one I would actively steer clear from is Unibond. Had some proper shite results with that and whatever you do, don't EVER buy their ready made floor adhesive in a tub!!!! Utter dog? As always, butter the back of the tile so its completely covered, and lay your notched bed on the floor, ( if the floor is good enough for one notch ), or butter, bed the floor, and then bed the tile too ( if its a poor floor that's needing making good but SLC is overkill ). Contaminants like plaster or plasterboard dust are not your friend, so mop the life out of the floor with loads of good old H2O wherever there is evidence of that. TBH a dry floor is your biggest concern so refer to my first and you should be fine.

Then leave the concrete as is

Negatory, ghost rider. Use the float

Lets just keep this between you and I

In a nutshell, yes. It'll never get full static pressure as its only dealing with dynamic flow. Will be fine.

It will be documented here for prosperity. "In for a penny...….."

That’s pushing your luck imo. A screed at that thickness will need to be bonded with a very good primer. If I was doing a Wetroom former ‘hand-crafted’ then I would be using a flexible tile adhesive to bench it all in. ( just so happens that the next en-suite will be receiving a bespoke 900mm x 2700mm Wetroom walk-in shower test made from scratch by yours truly ). Wish me luck. ??

Just the machined sections

Pretty good numbers to be fair Let’s see what the wee beastie produces on a bright clear day. Good result.

Input or output temp ?

PM only please

If all the TRV’s are knackered then we’re pee’ing in the wind here ma’am. ?

SolarEdge gets my vote. Good inverters with dry capacitors, and long warranty. SE inverters also feature 'export limitation' so anyone unsure of getting a yay from the DNO may wish to use them as a means to get a bigger system installed.

A pressure reducing valve on the cold mains at source sound like a good solution. Even if you turn the stopcock down to a dribble, the static pressure will be the same once it equalises. You were right to bring things into the year 2000, so stick to your guns. Just a shame the plumbers didn't give you a bit more advice on the pro's and con's before getting paid and moving on. Still doesn't make them terrible, just a bit complacent.

Not entirely sold on that statement, biased as I may be. I have heard plenty of woes where there was little or no synergy between 'fellow trades'. Unless you intend to PM them and make sure that there is constant and recognised dialogue between trades, don't expect that to 'automatically' go well. It will require your continued intervention and constant double-checking that things are being executed as promised. Asking questions and including the replies in the contracts will be your parachute. Tell the chosen professionals that you will expect the systems to work, exactly as they have been asked to, as in what they promised when they quoted to supply them as fit for the described purpose. Assumptions will kill you dead, and trades will hang onto those for dear life for defence if / when you overlook things and don't cement them as the expected criterium. This can be very easy, or very hard. Many on here report varying mixed bags of results, but the information is here by the bucket load if you wish to search for it. The good news is people here have shared the good / bad / and downright life-changing ugly, from which you and others may benefit. I know I have Fill your boots

Ola! Yes, turn the upstairs ones down to 3 ( out of 5 ) and try again as the sooner they get to temp and start to strangle flow the better it’ll be for downstairs. 3 on most is around 21oC, but if your valves go to 6 or higher then choose the halfway mark. You’re just overheating the upstairs rooms otherwise. ?