Nickfromwales

How thick for what? Wall or lintel? The reference to 100mm is for each end of the concrete (pre-stressed) lintel to be sat over 100mm masonry the same thickness as the lintel. For this, you’d be using a 3” x 4” lintel https://www.diy.com/departments/expamet-concrete-lintel-l-1050mm-w-100mm/150790_BQ.prd

Need to see a section drawing, then it'll make sense I guess.

They've not blown cellulose over the Finks on the last two of their projects I worked on. All of the CAT6 network gear and TV runs, plus feeds for all the blinds etc went up there on the most recent, and we boarded it out so it could provide quite a bit of useful, additional storage.

100mm in concrete is fine.

Well worded aka "life". Good to hear the builders already on it though.

Cant really say from the pic, but if you’re getting movement then it was defo air locked. Happy days.

Looks like 1/2” BSP, but would need you to buy a fitting and prove it obvs. Then one of these can be put on the end with 21 turns of PTFE, if you’re feeling brave. You put a short (100-150mm) piece of copper in the 15mm entry and then use a push fit connector to go from copper to plastic, if you’re using push fit? Don’t put push fit into the compression nut or the 4 horsemen will descend upon you. Failing that, I’ll just disapprove.

No rush! Those days are long behind me

Bingo. We're getting somewhere. Did you hear the F&E tank ballcock allow some more water in to top up?

I’d switch your PM inbox off sharpish, if I were you lol! Congrats, I’ll be in touch myself pretty damn soon if you’re up for some new projects to support me on. Last lot didn’t make grade….now gone ‘adios’. Shoot me a message when you get 5 and we can have a chat or maybe meet up. One’s on your doorstep.

“These are not the droids you are looking for……” 🖖

Defo this. Use a battery multitool and have a hose running to manage dust. It’ll wash off the render if it’s not left to settle. Leave the section held captive by the render, and mastic the joint to recreate the weathertight seal. Be sure to multitool the full length of the underside of the bit you need to remove so you can lift it away from the render. Don't simply hope the render will be ok if you just lift the cill up and away. It needs to be disconnected by you just multitool’ing inti the render for maybe 5mm or so. Steady hands and lots of time and patience invested here will make this quick and simple. Rush it and you’ll be into another few cans of real ugly worms.

As the principal designer, and I assume the author of your b regs drawings, they are responsible for the insulation being fit for purpose and sufficient for a “pass”. If their spec is under then it should fall back on them?

Are you aware of our marketplace?

I try to explain the difference, to folk who approach me (both here by PM or in “real life”) for ‘a bit of advice’. I have to explain that me rambling on here has zero repercussion, because in reality nobody should listen to a word I have to say. But, if someone asks me specifically, to advise on their project, well that requires time, and time = £xxx At that point I become liable or responsible for not overpromising or under-delivering, so that’s now managed via my T&C’s (serves myself and the client very well if expectations are managed robustly, and then each party knows what’s been promised vs what’s getting delivered for what sum of money, payment plans agreed, and so on). It’s so much simpler when 2 adults can read the same document, perform a handover, and agree that’s all been done as expected and here’s your dosh. BH has a massive wealth of information available for anyone to read and use, with their own caution needing to be in check, and due diligence performed, eg to avoid misadventure. Reading a few bits on the internet is not robust enough to go spending your hard earned money on. It should be used to compile questions for your chosen contractor, or as a sounding board for your own informed decision making.