Neverfinished

Roof was renewed in the 70's to a cement tile in an all-round poor quality job, now needs doing sympathetically, & back to slate (though possibly with some IN ROOF solar on back elevations). 1. Its a cold roof, see pic 1, showing SE & NE elevations. A main issue is - to up-grade its thermal element extra insulation on interior side of (original) attic room of greater than 40-50mm would be impractical due to already restricted room height & width, see pic 2. So, I'd 'try' adding insulation above rafters, complemented by the PIR between rafters, (& then makes it a hybrid roof, as Redbeard reminded me on here). So I see raising roof height (by say 50mm) basically being essential, to get to regs, & being 'engineered' by way of a counter-batten etc; but its also necessary my roof 'integrates' with my neighbour to the left side (using a bonding gutter of some comprehensive design I guess, though my B.C. officer says such a bonding gutter, & perhaps additional lead flashing(s), no big deal!) I'm still going to struggle to get to a 0.16 U-value however much insulation I can get in/up there but see little other option. (Redbeard also mentions a 2-thirds above/ 1-third below-rafter rule of thumb for insulation to avoid the 'interstatial' enemy). Q) Has anyone else any thoughts / suggestions on my meeting my 0.16 U-value for insulation requirements or even approaching - B.C. look sympathetically at draughty old properties . . they say. 2. I include below a link showing how TLX (gold, a multifoil) suggest their product be used above rafter in build-up of roof thermal element -including a counter-batten, stated as 38mm (old regs?, presumably now 50mm?), & which also provides ventilation on cold-side of roof. And this would raise my roof +/- 50mm). See its detailing & spec. here:- https://tlxinsulation.co.uk/wp-content/uploads/2021/08/TLX-Gold-Counterbattened-plus-50mm-PIR.pdf 3. It says, in this link, that TLX multifoil used to build-up thermal element with this product, including air gap/s, above rafter, followed by 50mm PIR/phenolic within rafter, has a U value of 0.34. So, if I were to indeed add a further 40-50mm max. PIR (thermal conductivity .022 W/mK) to the inside, under plasterboard . . would this 'build-up' get any where near the 0.16 requirement? (its beyond me to calc. this myself!). a) Anyone else care to comment further on my thoughs on this insulation detail? b)also what do you/others REALLY THINK about these multifoils - do they actually work (as long as fitting + air gaps adhered to) . . or not, & actually meet U values claimed? c) Also I'd be interested to hear from anyone about design/detail of a succesful bonding gutter - my roof will be in ~10mm slate but raised say 50mm as explained : meeting neighbour's cement tile. Many thanks, Stephen, Leicester area.

I need to re-roof/slate my 'typical' town-terrace property + upgrade its insulation. As a 'hands-on' tradesmam/handyman my work included small roof + gutter repair issues etc; So whilst aware + competant of some of the work & its detailing to meet regs, I need an amount more knowledge to accomplish everything this entails. I plan to be hands-on, assisted by say a roofer/tradesman (retired?) able to work up to the high standard I desire. I think, to obtain the guidance needed I'd best seek some practically orientated on-site advice/consultation, perhaps from a local roofer (retired?) or architect. . . . Can anyone suggest the precise profession/type of person to ask. I DON'T want to be just fed theory - I want practical tips & a site visit or 2. I'm north of Leicester. Info about current roof etc:- Roof renewed in the 70's in cement tile in an all-round poor quality job, now needs doing sympathetically. My finances are limited - I'd input some tools, be hands-on + my limited knowledge; further motivated to keep job in-house as scared of being 'hoodwinked' by a deceitful professional. A bonding gutter will be required where my roof joins neighbour, see left on photo 1. Is a cold roof - but to up-grade its thermal element I'd ideally now add insulation above rafters to the existing between rafters, thus course raising roof height by say 50mm too, but possibly unrealistic! . . as need to integrate with neighbours roof. Adding more insulation within existing attic room impractical as seriously impinges on current limited height/width. Thanks any suggestions.

Hi, IGP. I came across your recent post & photo just now. I've just joined Buildhub with a question 'Laying hardwood floor over suspended floor joists; would any underlayment help?' Your posts & responders have helped answer my question to an extent, so thanks. I've paid £1700 for new floor planks to cover a room similar size as in yr photo & don't want them to rot, want optimum insulation too. Found the article in the thread - 'Best Practice Approach To Insulating Suspended Timber Floors' really helpful & plan to follow it. Sounds expensive though! I attach a photo showing what I'm doing. Will wrap it with the appropriate membrane(s) but leave the insulation @ current 80mm as concerned to keep the joists breathing in part at least. Got the fireplace & hearth to upgrade too. Cheers, Steve/Neverfinished

Hi, I'm about to begin lifting the original 'pine' planks flooring in my victorian terrace home. Then to lay American Ash (19Depth x 138mmWidth) planks, & I could just lay them again straight on the joists as originally. Being on the ground floor, there's the typical 3ft 6in ish 'crawl space' beneath, which has a well designed 'air-draught' thru; And at base just the original reasonably dry soil within brick foundations. See photo attached. I've added 80mm of Celotex between the joists several years ago. Original planks survived fairly well in the environment just described though had cupped, doubtless a long time ago, & had been 'face nailed'; I'm thinking I'd secret nailing this time thru groove in T & G might minimise cuping this time? Would my new floor also benefit from 'shielding' from the elements, especially water vapour, down in that under-space? Perhaps I lay a 6mm plywood base ? &/or lay a Tyveck type breather membrane, on the joists ? I've been a decorating, some carpentry, tradesman for years. I'd much appreciate anybody's ideas / suggestions before I start. Thanks in anticipation !

Hi, I'm about to begin lifting the original 'pine' planks flooring in my victorian terrace home. Then to lay American Ash (19Depth x 138mmWidth) planks, & I could just lay them again straight on the joists as originally. Being on the ground floor, there's the typical 3ft 6in ish 'crawl space' beneath, which has a well designed 'air-draught' thru; And at base just the original reasonably dry soil within brick foundations. See photo attached. I've added 80mm of Celotex between the joists several years ago. Original planks survived fairly well in the environment just described though had cupped, doubtless a long time ago, & had been 'face nailed'; I'm thinking I'd secret nailing this time thru groove in T & G might minimise cuping this time? Would my new floor also benefit from 'shielding' from the elements, especially water vapour, down in that under-space? Perhaps I lay a 6mm plywood base ? &/or lay a Tyveck type breather membrane, on the joists ? I've been a decorating, some carpentry, tradesman for years. I'd much appreciate anybody's ideas / suggestions before I start. Thanks in anticipation !