zoothorn

Hi dpmiller.. the pozi-joists/ ceiling shown in pic top of page 2.

Hi @andyscotland I thought the idea was to foil -and also- placcy sheet, a belt & braces plan? I'll be very relieved if what I've done is even a fairly-sufficient barrier, & I've negated the need to placcy sheet it. Can you confirm this? Re. the reveals. Ok I've got 2sqM of 25mm of PIR left from kitchen job. So instead of buying costly insulated-pB.. which I'd need a full sheet of just to effectively do 4 reveal sides).. & the fact that I can literally only get 12.5mm IE half thickness of any PIR in (+12.5mm pB offcuts to use up too, makes sense = 1" total material, MAX, due to my builder not giving me much room L&R).. so I was thinking foam-stick my PIR cut halves (only 20cm wide of course, so cutting w'breadknife doable).. then screw-on my pB. I can't think how else to line these sides, with at least some insulation, if its even needed, to max 25mm total material.. without doing my plan.

The joist width is indeed 100mm. So if 300mm gaps between, & 400mm centres. Just measured to check. (The joist height.. I think n/a just for now.. is 200mm).

Ah dammit sorry I'm getting my centres & my gap widths mixed up. Inexperience. My gaps between joists are known @ 300mm. (so my centres are gonna be.. 400mm then is it).

Hi PeterW.. about to buy some clip jobs today (you suggested after Onoff's reading of '90mm clearance'). So just going over my led instructions, to concur with Onboff's 90mm clearance figure.. to ask clip seller what clearance each might give me. I've just spotted the last tiny point on the 'warning' list (after "min 50mm from joist etc".. "minimum ceiling void depth 90mm").. "The fitting is suitable for covering with thermal insulation". So, are these are ok for my insulation to sit ontop of in fact.. or am I missing something? (maybe Onoff interpreted the ceiling void min depth, as the needed clearance from light > to insulation).

Hi ProDave Ok understand that. But, I was under impression that this stuff comes in 400mm x 1200mm rolls.. so in my case I'm sure someone said to always use more than my stud widths in order to get it to stay in? mine are 300mm centres, so wasn't 400mm said to be correct? I cannot find it tho. I know its simple to all here, but I'm all at sea having never done this. I don't have luxury of doing any of these small steps/ jobs again, or redoing, so takes me 2 days to do X (plus hours of research before) that might take anyone experienced 2 hrs. So in your case here, you had to put in many, many sections.. because they were only 400mm long-? (assuming your rolls were 1200 x 400.. divided into two, so dozens of 600mm x 400mm very very short sections. I just don't understand.

Been foil taping mad. Done top room reveal: builder left me with not enough either side of window, to line the reveal (sides) with even 25mm PIR > pB over. So my plan is cut a 25mm PIR in half (tricky) > foam fix it to the foiled reveal sides > pB with long drywall screws, thru PIR, into timber. Is this a good plan? I just can't deal with plastic-lining the upstairs room, let alone both (its a job too much for just me).. so tried to foil really well instead. Foil job alone took me 2 days. I did look at one screwfix sheet roll but couldn't see it properly, so couldn't guage how tricky the job might be.

@ProDave could I pick this thread up (today buying my fluff). Your frametherm 35 stuff ProDave.. could you remind me of your joist spacing width, & what width fluff you therefore chose? thanks- zoot

Ok thanks for that- I should be able to cope I think. So do they feed standard water-rads, with the usual (a design disaster IMO) trv's ?

So effectively in the summer, sitting outside (my gdn fairly close to the lump).. its not gonna be doing any noise, at all? Its just the noise outside being of concern to being in the garden, being a very rural & peaceful spot I'm lucky to have.

@ProDave or anyone else who knows of these systems.. are the units noisy at all? I forgot to ask the chap.

I think its fairly swiftly onto the next step.. an engineer chap re. logistics of doing it all.. maybe visiting next week. (☺️)

@Mike actually you see I do fall into this 'poor wretch' catagory.. low income, old cottage, no C.heating, fuel-poor. And as for my clothes jesusH.. for eg my y-fronts: its only the stubborn understains that are holding them together.

Yes that's it. surveyor from the Co came, logo on/ all pro as you'd want: the pump would be a "Vailant" unit (~same size as my twin reverb). Cavity fill would be eps (small balls of I think) alone, no bonding agent: more up to date than the horror-story stuff my builder talks of needing extracting from what I can gather.

Hi Mike, thanks for the post. Apparantly out here westest/ wettest wales, there seems to be a big chunk of cash designated to a Co. called C.E.S, by govt, who seem to have the contract. They had a few postcodes on their books to allocate grants to, but now stretched to include whole of my area too.. so they said.. so 'luckily I'm now in catchment area'. I mean on paper it sounds like too-good-to-be-true door-salesman talk, but for the fact that a whole C.heating system -possibly- can be installed via a full govt. grant. Anyway we'll get a better picture after the surveyor visit this AM, I'm waiting here for him. So it seems I don't have the choice of Companies to choose from do I? if afaict, if this Co's been given the contract by govt. I'll get back on here with details of the system proposed/ offered by the surveyor (or call "CES" & get this more specific info) & post back. Great help chaps thank you- zoot.

Hi A-L Yes, I think exactly so (eco). Onwards from your question.. I can't understand a thing, I do apologise! Apart from the cootage size: no its small, simply a 30msq main room (within the 4 old walls).. with addition above this (2 small beds) & 1-floor kitchen & WC tagged onto its side.

@ProDave I assume rads too (I have no rads now: just a logstove, 2 leccy wall heaters.. for whole house). The efficiency isn't paramount, to me.. the cavity insulation (both brick additions, are as stupidly cold as the main C1830 stone walled room) plus having -anything- in terms of C.heating is: I'd even say a luxury compared to what I'm used to here! Its a Q of if there are any hidden pitfalls I'm totally naiive to, really is the nub of the thread (& secondly, if the idea for my house.. might seem a decent one). One minus-point to the system afaict, is it won't go hot-hot.. but if its 'medium' & I benefit from both this in conjunction with a cavity wall-fill, then it might just be spot-on. Surely it'll add some value to property as now having "Central Heating"-?

Hi ProDave, did read your thread before posting mine.. good Q. Ok yes the new ongoing extention.. is timber frame. But I didn''t include this in the description to the Co/ left this off. So excluding this (which I wouldn't need insulating as as Ive just put 140mm kingspan in/ the full whack poss): I have 4x walls C1830 miner's cottage -flippin cold 2ft stone walls- & cannot be adjusted (IE inside PIR lining is a no-no lookswise.. & I mentioned this). Then added to this simple 'shell': an 80's 1-story kitchen extention, plus, ontop of the 4 original walls: another 80's addition of 2 bedrooms. BOTH are 2 courses brick with no (or 1cm in fact) PIR inside the cavity: mentioned this & they said 'as good as none/ we'll call it no insulation in' (which is great news).

Hi chaps- apparantly I'm eligeable for this system to be installed, foc via a full grant, in my stone cottage + 70's cavity wall additions (2 beds above, kitchen on side). I'd never heard of it until the call an hr ago, so doing some research. Apparantly in order to have it installed, the Co said I 1st need the cavities filled (also via a full grant/ they would do this 1st.. I think). Can anyone suggest any reason why my having these (cavity fill, ASHP system installed) in my particular house isn't a win-win? I bet there are caveats & I shouldn't just jump in (I mean surely I can't be onto such a winner too: all done foc?!). I'm having their surveyor chap here tmrw to assess xyz.. be good to swat up beforehand. Appreciate some basics- zoot.

Hi PeterW.. just back doing this job, flat-out (paid) work deluge. Ok yes- left the old wall (old outside of house) exposed. Idea is to see how warm room is.. & if this wall's a huge 'cold radiator, then I'll line it later. I hope not to tho (may even sand-blast the render off to expose the stone if warm enough). Re. the foil: what's best to do in the reveals? foil > (sheet) > pB? or try & somehow line them.. prob is, I've only got very limited window frame area to put 1" max insulation > then pB. I'm inclined to do without PIR here, if I'm allowed to.

Ok good that's a plan then- great helps progress having clarity on the next job. In the meantime I'm mostly thru my top room foil-taping job. But some Q's.. I've done the vertical timbers, but left the last two that join the house old wall (the end of my house, as it was): here its quite in-out with gaps between timber & old orig wall face, so Ive foamed the gap. So Ive got about 1" of timber left not foiled, then a foamed gap, then my old wall. Do I foil around > just onto my old wall? or just over a bit to just cover the foam?

I think this hits the nail on the head, if not the seal-proof design of Onoff hood jobs. Great idea this Peter, I think.. So is the idea thus: I whack in my frametherm 35 fluff, stuffed in like ProDave's between his posi-joists.. then put up all pB's. Once all pB's on presumably having a mark or drilled wee guide hole for my 5x light placements.. my spark1 cuts his round holes / fishes out cables / fits these spot-clips (pushing up the fluff) / fits the spots as per normal. ?

I hadn't the knowledge to know (right up till the new word 'hood' even mentioned only hrs ago) that all downlights didn't require a cleared space/ no idea you could actually choose some that don't need it. No idea they even existed. All I can do is talk to my spark1 & he shows me what options: he cannot be expected to forsee & suggest a special type that doesn't require the typical space/ cleared area. And I can't really afford a 'special' type anyway, probably.

@Onoff well from advice of spark no.1 I bought these weeks ago (& taken out box plugged one in for test, good £ & colour temp/ me happy): https://www.screwfix.com/p/lap-cosmoseco-fixed-fire-rated-led-downlight-contractor-pack-matt-white-500lm-5-5w-220-240v-10-pack/891gx

@Onoff & Peter.. tbh I've no idea whether I need or not! the reason the hood idea proposed by Onoff, was bc my spark wants a flippin big (~10 inch) fluff 'burrow'/ space made around the led downlights. Now, I don't know if these even need such a big hole made, or any at all.. whether the fluff can actually be fine being in contact. As with much in life, its all down to the size of one's fluff burrows.