Nickfromwales

Every stroke of the 'pen' has been considered for my current client, a plot on the highest elevation in their locality, which includes mitigation of the noise of water dripping from the window heads on to the metal that forms the window sills below; nothing worse than the 'Chinese torture' of a single drop of water hitting a window ledge like an annoying metronome. I've recommended installing sound-deadening 'killmat' to the underside of each of the sills before installation, to prevent such annoyance. Folk just don't know what their next (albeit preventable) enemy is going to be. That's where I come in lol. One look at the section for the above roof, and I would have said "feck, no!". Simpler to solve when it's on paper or a screen, where the drill and hammer are the left and right clicks of a mouse.

You roof leaks. My thoughts are, that your well regarded builders have made you a house with an indoor irrigation system. That's a pile of shite. Get them to come back and remove this optional extra, end of. I was referring to them being further out, not further up. They are defo way too far 'in' as shown in your first pics. Sorry, but it looks (and preforms) like shite. No dice.

If we were giving out trophy’s for opening one’s mouth to change feet, @Benpointer would need a bigger mantelpiece

You can’t wet plaster these reveals in, over a modern cavity / cavity closer, so your example of a 60’s returned masonry reveal isn’t apples for apples re the OP question. For your job the advice would be different again.

If you need to cover 100mm then you’d be looking at minimum 2 runs of 60mm tape to do that, I’d go 3 for robustness and to give a decent overlap. You can buy thicker tapes, but you just end up trying to buy the right thickness tape for xyz locations and as a contractor it just isn’t economical. Wider tape costs more than narrow tape so 🤷‍♂️. Yes, self builders are mostly all loonies, so I am making plenty of adjustments lol. Sand and cement doesn’t really parge well, unless you mix a bit of SBR in and get the consistency perfect each mix, then it still goes quite granular as you spears it out and the masonry almost immediately sucks the moisture straight out of it. Then it’s like making thin sandcastles on vertical surfaces, give it a go if you wish, which is where you will thank me. I accept all major brands of beer / IPA. Remind me are you using AeroBarrier or just tape / foam / parge / liquid AVCL? Are you saying you’re going to spray the whole house interior with liquid AVCL??

Yup. Let’s be honest, if you’re ‘accessing’ the plywood you’ve smashed all the tiles up and binning them so are ‘all in’. If you want the tiles to stay down, you go ‘all in’ on the installation and enjoy the longevity. You could always fit 27, randomly positioned access panels on the ceiling downstairs.

I just don't like the brittle nature, and I've done UFH with P5 + plywood so many times with great results, I just don't want to change. If it works, then happy days, plus the plywood conforms to the floor shape / undulations, whereas cement board will just snap or fracture, no Bueno afaic, sorry!

Who are the intended occupants, and what are they going to do in it?

Go for spreader plates, but allow some rockwool under them, atop the PIR, so the plates are sprung upwards slightly. Then, when you screw the 22mm P5 deck down there will always be great surface contact between the aluminium plates and the underside of the P5. Without this, the heat transfer suffers somewhat. I've never used backer board and only ever 6mm or more of plywood (glued and screwed down) and then tile straight onto the ply. For 6mm ply and 22mm deck you use 25mm 4.0 x 25mm screws to lay the ply so you don't hit a pipe.

Great progress again. Fingers crossed for the move in.

...or "home slaves". MVHR just ticks over and you go about life. Just why would you go for anything that needed any such diligence aka compromise on lifestyle.

Insulation means zero if there’s a draught. As said, I use a pair of £15 2kw fan heaters, in increments of 1x 1kw, 1x 2kw, and then fire up the second to the max of 4kw of space heating. 6m x 3.6m totally uninsulated ‘shed / workshop’ and the last 1m x 3.6m (partitioned off) is my desk / pc / printer and man sanctity zone. All the cost and faff of insulating it wasn’t high in my list as I only use it sporadically, or for planned days of Teams meetings with clients etc, and within 5-10 mins the space is plenty survivable. If I’d have made the metal profile roof roof less draughty then I expect it would require even less heat, but hey-ho! Does what I need it to.

Yup, including the surface of the plasterboard, meaning the whole thing needs doing again. Rod. Back. 👎

Not life or death. Carry on as you are sir.

Congrats!!!! 🥳

Leave the yellow foam about 10mm higher than top of screed, to deal with any splashing of screed or a ‘wave’ accidentally going over the upstand. Cut it back after the screed has dried.

I’d go with my above, simple, robust etc, and leaves a completely flush surface to lay flooring to.

How about some basic sealing up with foam etc? Gaps letting cold air in are killer, same with the window and that can be a couple of £10 to apply self adhesive B&Q draught proofing strips etc. Also these radiator fans seem to work well moving heat around. Link

Adding the upstand does add some additional thermal break, but any decent door threshold will already be reasonably well thermally broken, plus the foam gives immediate separation from the screed and the threshold / frame. Have the yellow foam against the frame, as expansion (should you actually need it) needs to be at the perimeter. You then fit the grey stuff with foam, so it doesn’t move, then trim that to be the exact height of the screed, so the screeders have a target to lay to. After the screed is dry, you then cut the yellow foam to the screed height. You could just double up on the yellow foam, but it looks like you already have the grey stuff so crack on. Stop and start the yellow foam in the internal corners to prevent gaps from forming a continuous radius, just apply duct tape to the back of the foam to create a hinge, then once fitted tight do the same to the front to keep it liquid proof.

I had one couple with a baby move in early, and overnight (minus a working MVHR) they got to around 2000ppm, which was making them feel ill the following morning (headaches / lethargic etc). That was with them ventilating manually through the day. With MVHR on the house became blissful.

Have you just tried turning up the flow temp by a few degrees?

Why make it such a pita to airtightness tape etc by screeding so late in the game? Sooner it’s down the sooner it starts drying too. Also nice to be running UFH if working though the winter. Did this on the last one where we boarded and skimmed the plant room very early on, just to get the ASHP in and running. Much nicer site to work on if you’re not freezing and the house doesn’t then have damp / mildew growing on the fresh plasterboards etc.

Brown envelope city.

Yes, but the fleas come with the dog, lol.

You may be ok, just giving a precaution.