Nickfromwales

Just trying to work out if it's quicker, and easier, and a better job to prop the 1st floor up and just drop that wall so you can do the job properly?

Nope, that’s completely wrong information, sorry. UG stuff is near idiot proof and extremely robust, and as it’s not got UV getting to it has the resultant longevity. Plastic soil stacks rising externally have been fine for 30+ years in direct sunlight. Not sure where you’re getting your information from, but it’s duff. 🫤

Yup, just get the end as thin as possible, and use that as a ‘leader’. Otherwise you’ve the combined thickness of the whole cable dia, plus the thickness of the rod taped to its side.

Usually you just use insulating tape and bind the two together, or the rods are threaded ends and you have a hoof or eyelet accessory that you use to fix the loose strands of cable to. Best to strip some of the sheath back so there isn't a nasty shoulder that meets each turn, vs having the strands (parted cores) and the rods first, then the sheath etc 300mm further downstream to make pulling it in easier.

Ok, we'll ignore you lol. Sometimes with a tile like that centring the gadget over the tile can mean that you then end up with a skinny rip of tile in the corner or end of wall, so you favour the shower being centre, and the tile cut being whatever, depending on your level of OCD; freakish to stratospheric etc. That make sense, #strato-boy?

Can you tell is why that section is so wide? Is it an old fireplace? Or a cavity wall with a chunk of dot and dab etc? Props will only shift if they’re on something soft, and also if you’ve not used enough of them.

If PB and skim, you only need to deal with it (internally) for FR, unless otherwise specified by the BCO. You need to get some clarification here tbh. If they’re happy with the rest of it painted (external element) then happy days. If you need a structure to affix the alu cladding to, then another option would be 9 or 12mm cement board which would negate the paint (you’d have to check with BCO but they should be happy with that), as long as joints are sealed with FR mastic

There are options for 22mm chipboard routered out, or insulated panels routed out (for the pipes), so get some googling done and check the responses here for related content

Who invoiced you? Subby or OSO? If you want an accumulator you can bolt a frame to the brick wall and mount it on to that. Local steel stockist should be able to fab something for you with ease, and then just bolt in place. Entire weight supported by masonry; I usually do outriggers to rest on timbers too, to help out, but would need more pics and details to advise. That’s doable. If OSO billed you, they need to put it right and you should only be dealing with them; after they middle-man’d you out of your money. If you went to a local all the money would have gone on the job, not have got split between the guys and OSO……

Maybe a IR thermometer will help. If you start at ambient and run the water to recreate the issue, if cold (street temp) water mixes through that valve you’ll be able to watch the temp of the brass dripping all the way down. Grab one locally in Screwfix or cheaper on Amazon etc.

Is the steel exposed to the room? Or will you stick PB to it so you can paint cosmetically?

You are allowed “deviations”, so that may well be in check. We do all often jump too quickly to the pinnacle, but life is life, and 80mm will have to suffice if that’s all you have. At this stage id defo explore doing away with the screed as you do not “need” it. Then the entire build up can be insulation.

If a refurb or addition, folk don’t have the luxury. 100mm minimum if heated, 120-140 would be much better. @paro I’d ditch the screed here and beef up the insulation. Fit an overlay UFH system (see Wunda website, good vids/info there) and then bond your hardwood floor directly to that.

You could stack 2 lots of 225x25, you’d just need to get inventive on the connections to/from, but doable. As far as temp is concerned, flow rates won’t suffer but you will get condensation I expect. That means the ducts need to run downhill to the outside wall so they can drip dry. With 2 lots of 225, you’ll have space for some insulation under the lowest one so that issue would be reduced significantly if avoiding using the full depth of the insulation to fit the duct.

+1 on needing trickle vents. Won’t pass b regs, and would make a horrible home to live in.