Nickfromwales

PIR is typically 140 IIRC so quite a difference, but PIR at 140 is way overkill for a raft etc.

Just remember that there are short and long staples Short staples are usually specified for PIR, but won't do jack in EPS. Specify long staples, and bang a load in, particularly on the bends and returns. The trick is to use you body weight to hold the pie down when turning / bending, and do not step off until the bend is formed and you're back on the straight. Expecting one clip to hold as you continue to bend the pipe will never work out. Use the longer clips for everything is my advice.

Hi, and welcome. A word of advice.... IF you do find a plot, tell NO-ONE until you own it! London is so densely populated, apparently the rats are saying amongst themselves "You know, you're never more than 5m from a human being"

Just make sure you zip tie the ducts tight to the lower chord so the cellulose goes over the top of them, bringing them into the insulated envelope.

Whack the ducts in, install a good quality airtightness membrane, hold the membrane in place with service battens at 300mm o/c's, and pump the bugger full of cellulose.

Happy days. The external was an "if" so don't panic about that. All looks good, but lets delete the assumptions All voids in the actual upstand need to be packed solid with rigid PIR. Foamed and foil taped to leave zero gaps. The joist depths are to be filled with rockwool / other?

Yup. Something like Marmox on the outside would help, but not essential. If you can get a 10mm board outside then do that too. The only thing I'd add is some continuation over the upper timber of the upstand, as you don't want any (ideally) of that meeting room temp. The issue is exaggerated here because heat will rise, plus moisture, and they'll both be trapped here and fighting it out against anything 'cold'. More Marmox with a chamfered tuck into the angled section would be beneficial.

Relax, we promise to not let you feck this up The worst cold bridging would be between the timbers at the top, and the plasterboard. Easy solution; use Marmox at 25mm thickness instead of the plasterboard and plaster it directly. Stuff everything with rockwool immediately surrounding the upstand, and Bobs ya Uncle. Not a single mention of Fanny, that would be rude!

Yup. You catch on quick, Sherlock.

Yes, the rotating waste is (was) a revelation. Have you looked at Diamond wetrooms? They have a clever tray which you pick up and rotate 180o and the trap moves 'sides' of the joists.

A decent tiler can make just about anything work.

You can do the same with regular tiles, just the cuts have to be a bit more inventive. Also, depends on whether you've gone for linear trays? Not too late to change and mosaic? Or is your preference for large-format tiles only?

All the area around the actual shower former (Wedi) is slightly elevated compared to the perimeter of the former highest point, eg so I could bench the mosaics in and have a fall all the way from the towel rad to the drain.

Eh? You cannot tell where the former ends if it's being tiled over?

I'd say that's possibly the slates cooling down each evening. Probably be worse while we have some sunshine, and almost disappear during winter. May settle, as new houses do tend to do these things.

Flow will be flow, regardless of duty, so the energy in the pipe gets preserved and delivered where it needs to go to.

You just bench the missing 100mm in with tile adhesive and an off-cut of cement board / other.

One pipe leaving will be flow at the manifold temp, and the return loop will obvs be at the lower temp. Deciding which pipe runs where offers some minimal but additional manipulation of this distribution. In a PH or thereabouts it does become almost moot as the slab will almost completely uniformly acclimatise and there will be very little difference between the two. I only insulate the pipes going to the far side of the dwelling from the manifold, mostly to keep whatever is in the pipe, in the pipe, until I want it 'out'.

You can't cut a 1300mm tray down to 1400mm?

Why aren't you putting formers down and tiling over?

I have no idea, just the only thing I ever hear that's reported as doing what you are hearing / experiencing has been the roof. Mainly SIP's roof and with metal standing seam. That's the only bit of the house that heats up and cools down (expands & contracts) quickly enough to generate noise. Do you have tiles / slates / metals?

Not in any of my experiences. BCO walked the job, warranty folk wandered around behind him taking notes.

Would be a good guess, seeing as it took so little to provoke this into leaking.

That's what I did on a build in Gravenhill. MBC TF so only a 35mm service cavity to lose the tails within, and SWA just would have been impossible to get where I needed it to go. Flat bar from B&Q iirc, and shows up well with a stud / metal finder.