Nickfromwales

It’s unfortunate, but the moment you turn your back it’s down to the people you chose; eg that they are able to perform admirably. This is when you find out who you chose, but as said above, often then too late to rectify and you’re left holding the baby. On a job atm where the admirable but defo didn’t happen, quite spectacularly, but now there’s a new team and some (quality) control and it’s been recovered quite quickly. When first there it was “down tools, pick up tape measures, and get the laser out BEFORE you do anything”. Found a few extra hidden faux pas, and then some, and made sure the guys got those deleted before ploughing on. You can spend more time panicking about what’s not right, vs just inputting the energy into getting it sorted and moving to the next item. @Stu84, throw a 0-10/15mm bed down and leave it to go off, then offer the blocks down in another bed, tap it all into shape, and leave to set. Then you’ll have a (level and plumb) blank canvas to work from. By the time you’re on the 3rd course you’ll have all but forgotten about this. Oh, and don’t even dream about taking a beaker to this!!!!!!!

How cold are you running the cooling?

Ask me and the good folks here. We speak from experience, which is gold dust

Too much money on double-pumping then? Plus no screed companies want to pour less than 50mm unless it's had a very expensive primer applied beforehand.

+1.

This is average, but should be for design and on-site commissioning, so if just for design it’s time to look again.

Yup. You are overthinking, so stop it! Lol. 😜. If you’d like to move on with your life, please do the following. Get some Marmox or ‘other’ tile backer board from a local tile supply outlet (Topps carry these at 6 and 10mm). Get a couple of sheets and cut the first one to drop down into the void to fit against the outer wall completely; for the first piece going against the door you need to leave this as high and wide as possible to act as a shutter to stop the SLC / concrete getting to the masonry. Get some Illbruck FM330 foam to use to bond this to the masonry, and use it to seal the edges, eg so no external masonry can be seen, just board and foam. Leave to cure, then cut back any foam snots. You’ll need something forced into the void to keep the board in place whilst the foam cures. Buy the proper gun grade foam and a decent gun, not the cans with the single use bendy straw!!! Then do the same again against the internal block, leaving it high again. Leave to cure, same detail. Cut a few more pieces of the board to drop in between these taller boards, full width, say 35mm shy of the level you want for the flooring to fly over. Keep cutting these and dropping them in until the gap is pretty much full of backer boards, like a sandwich. For today’s exercise the sandwich will be a BLT. Once happy the void is as full of boards as it can get, withdraw these shorter boards and set to one side. Soak the area with water, immediately prior to the next steps. Sopping wet is fine, bone dry is bad. Then you drizzle about 3” of foam into the bottom of the void, so there’s an entire bed of it at the bottom, left / right / centre and front / back. The slower the foam comes out of the gun the better the bed of foam will be. Then go back and forth from bottom to top to cover each piece of white EPS in the cavity as best you can. Then immediately drop the cut boards down into the wet foam, one at a time, applying foam to the back of each, and then setting it upright against the last; as the gap gets tighter you’ll be able to apply less and less foam, don’t worry about it, just get as much in as you can. Then fill the remaining gaps at the top and sides with foam and leave to cure for about 2hrs; you can force the foam gun nozzle down into the gaps to get it most of the way down, but don’t push on the canister! Do this obvs whilst the foam is all still wet. It gets messy so keep one hand on the gun handle and a glove on the other to move the boards about. Set the foam to come out slowly so you can squeeze the trigger without having it come out at a crazy pace; this is easier than trying to manage the job and be the throttle for the foam at the same time. Have some gun cleaner to hand for any cleanups. Prob a good idea to have some weight of some sort to keep the boards held down whilst the foam cures. Get a rubble sack or bin liner and wrap the underside of the door and the threshold, as the foam (when left unattended) has a life of its own and can spew out and get on to the things you don’t want it to. Keep an eye on it for the hour or two that the foam is still curing. Once set you can cut / neaten the foam; you’ll then have a rock solid basket ready to take concrete backfill. Use 10mm aggregate, or just use Mapei builders screed (which has fibres in it) and back fill as required. Once cured, cut the taller boards back so suit. Using the “Marmox BLT” method will leave you with a series of XPS boards which are sitting down on the substructure, and that’ll be good enough to go barn dancing on. Yee-ha! 🤠. The end.

There will be nothing left of the boards by the time you wrangle them to the void. We’re currently installing them (22mm) on a clear open roof, and all you have to do is say the wrong word and the corners or T’ / G’s are fecked. These are a good choice, they are a plus, but you getting these under there, in one piece, to do that job, ain’t gonna happen. If you think that preventing repeat cold bridging on a cold (unheated) floor will make any difference, stop. It won’t. Just put some strips of XPS on top, and raise the floor by the thickness of that XPS, lifting the infill insulation to the same height. Focus the time, money and energy you intend to use up on under-slinging that wood fibre board, on draught-proofing, as cold air infiltration trumps all the insulation in the world. Don’t waste time and money for only microscopic improvements is my 2 cents.

Just put the common (C or L) and the switched wire (L1) together in the same terminal and see if they come on and stay on.

Looks like you'll end up popping a few tiles off, and then drilling down with a 600mm sds bit at 10mm dia, and then resin bolting the wall pate down. You know the only other option is to cut some slices out of the interior......

My money is on the dimmer. Can you swap it out to a regular switch and se if the lights stay on and function normally? My bet is they will. Remember that dimmers have a max rating, but more importantly a min rating too, so these needs to be chosen to suit the load exactly.

Ouch! Ready mix all day long, even if barrowed in.

I’ve been at this for > 30 years, and my ass still goes through various differing diameters whilst the wagons are backing up; at that time the opportunity to check / change anything has completely evaporated.

Hi. How much is astronomical? People have very different ideas of costs etc in my experience.

I’d go level -3-5mm as your target, and then SLC each room to get it spot on, if you insist on DIY. Or pay a liquid concrete company to do the pour and admit this is a huge undertaking to get flat first time as a DIY project. Some battles you can’t avoid, others you can pick and choose. Professionals will pour this in one go and get it pretty damn near perfect for you, with zero stress, plus the onus is on them to get it within their stated tolerance.