janedevon Posted June 30, 2016 Author Share Posted June 30, 2016 I just appreciate the impartial advice from here, id be stuck without it first build a lot to,learn and its great to hear peoples opinions, i dont get to worried hard sell just makes me more determined to get as much info as i can prior to making a decision everyones opinion here is valuable, lifes too short for arguments and stress god knows we all have enough of that if we are in the self build game. thanks guys i hope you look forward to my next questions!!!! 1 Link to comment Share on other sites More sharing options...
Nickfromwales Posted June 30, 2016 Share Posted June 30, 2016 Thanks Jane. There are many rides at the funfair not just this roller coaster . Feel free to choose another, just please keep your arms and legs inside the carriage at all times until the ride stops ! The managment. Link to comment Share on other sites More sharing options...
janedevon Posted July 5, 2016 Author Share Posted July 5, 2016 Me again, with more probably simple questions, so we have sorted my plan for the warm roof living space as discussed esrlier in the thread, the timber frame guys have left today, and the main house roof has been sarked, the rest of the house, cold roof hasnt been sarked and oddly on my plan there doesnt seem to be specific insulation specified, so as far as i see it i will counter batten the sarking to leave an air gap then felt and batten and tile and insulate with my 2 layers of 90mm earthwool, then im using 50mm of pir under rafters. As the rest of the roof has no living space in it and no sarking does that negate the need for counterbattens? And what is standard roof insulation in a cold roof? 2x150 mm rock wool? Or something more substantial. feel free to correct me if im wrong im here to learn. thanks Link to comment Share on other sites More sharing options...
janedevon Posted July 5, 2016 Author Share Posted July 5, 2016 They say a picture paints a thousand words Link to comment Share on other sites More sharing options...
Stones Posted July 5, 2016 Share Posted July 5, 2016 Unlike Scotland, I don't think sarking is a requirement in England, so it may be they will just felt and counter batten that area. I'm just finalising the insulation of my roof, and one of the options is 2 layers of 90mm knauff frametherm 35, and 50mm PU beneath rafters. Taking into account roof timbers, gives a decent enough U value of just under 0.14 for us. In my flat ceiling section, I have 420mm of earthwool specified (3 x 140mm). Link to comment Share on other sites More sharing options...
janedevon Posted July 14, 2016 Author Share Posted July 14, 2016 Hi again guys just a quick question reference the above pic on my build, had the building inspector around today she was checking roof structure and talking about insulation for the roof, i said the sarked roof is a warm pitched roof which will have inulation between and under rafters then the rest is cold roof which will have piles of earthwool inside, she said no its all a cold roof as to be a warm roof the insulation needs to be above rafters and the rest of the roof ie the un sarked area would still need between rafter insulation. she left me a bit perplexed and when checking my plans the insulation is as i described, i do however have a bit of a quandry where what i call the cold roof,cuts,into the warm one presumably i just carry all the way down with between rafter insulation and try to avoid cold bridging. the sarked area has counterbatten the unsarked area hasnt. any clues? Link to comment Share on other sites More sharing options...
PeterW Posted July 14, 2016 Share Posted July 14, 2016 http://www.dupont.co.uk/products-and-services/construction-materials/tyvek-building-envelope/uses-and-applications/warm-pitched-roof-construction.html BCO is wrong ..... bit at the bottom says how the membrane is used in a warm pitched roof And this is the accredited detail from the planning portal. 1 Link to comment Share on other sites More sharing options...
janedevon Posted July 14, 2016 Author Share Posted July 14, 2016 Thanks for that, how about her idea of between rafter insulation on cold roof i have only batten over felt so no air gap i thought the idea was rockwool above celing allowing a lot of air flow there Link to comment Share on other sites More sharing options...
PeterW Posted July 14, 2016 Share Posted July 14, 2016 Cold roof only needs insulation at ceiling level - start adding it further up (especially with PIR) and you could create a condensation problem. Link to comment Share on other sites More sharing options...
janedevon Posted August 28, 2016 Author Share Posted August 28, 2016 Guys when timber frame company left i got left a good few bales of frametherm 35 unused, the thng is they are 140mm, obviously i was aiming to use 2x90mm but is there anyway i can use these up, is packing two in between rafters detrimental or can i use these with something else to top it up? Could save me a few quid Link to comment Share on other sites More sharing options...
tonyshouse Posted August 28, 2016 Share Posted August 28, 2016 Cut and fit, neatly and go for it. It can be delaminated too and used as 140 + 40. Don't squash it or leave gaps, 1 Link to comment Share on other sites More sharing options...
janedevon Posted August 28, 2016 Author Share Posted August 28, 2016 Thanks yes just tried a bit split a batt into 3 so got 140 plus 40 ish and looks fine, means i can save a few quid theres 10 or so packs over Link to comment Share on other sites More sharing options...
janedevon Posted August 31, 2016 Author Share Posted August 31, 2016 quick question do i need to leave a 50mm gap under sarking board when i put this in? On top of sarking i have breathable felt counter batten then batten then slate? getting confused after so mich reading as to wether i need to leave this gap when i fill between rafters thanks Link to comment Share on other sites More sharing options...
Crofter Posted August 31, 2016 Share Posted August 31, 2016 No ventilation gap required if you have breather felt on top of the sarking. There is confusion in this area because I believe if you don't have sarking, you need to leave room for the felt to sag. 1 Link to comment Share on other sites More sharing options...
Temp Posted August 31, 2016 Share Posted August 31, 2016 3 hours ago, janedevon said: quick question do i need to leave a 50mm gap under sarking board when i put this in? On top of sarking i have breathable felt counter batten then batten then slate? No gap (ventilated or otherwise) needed under sarking boards as you have a breathable membrane on top. The counter batten raises the tile batten off the felt/boards so that water cannot pool above the tile battens. Link to comment Share on other sites More sharing options...
janedevon Posted September 15, 2016 Author Share Posted September 15, 2016 (edited) Ok so its now insulation time, started today with what the timber frame company had left me as spare. a few questions if you knowlegable lot could help out, im going 180mm frametherm topped with 25mm celotex then vcl prior to boarding. do i go right down to soffits with insulation? and what happens where my warm roof meets cold roof? Do i continue my frametherm right down? in the eaves there will be celotex 140mm between and behind studwork and what happens on the flat spaces above the dormers im putting 300 mm of earthwool over voids before boarding do i continue my batts all the way up as well? couple pics to help Pic 2 shows where warm roof will meet cold roof near the miriad of ducting Edited September 15, 2016 by janedevon Link to comment Share on other sites More sharing options...
PeterW Posted September 15, 2016 Share Posted September 15, 2016 I take it the plan is not to insulate any of the pipework as its all clipped together ...?? Link to comment Share on other sites More sharing options...
janedevon Posted September 15, 2016 Author Share Posted September 15, 2016 Only tied with old electrical flex at present just to neaten it up we up to 200 of duct and not,finished yet,, in between rafters ive put a layer under duct before putting some over the top Link to comment Share on other sites More sharing options...
janedevon Posted September 15, 2016 Author Share Posted September 15, 2016 Plumber will be insulating water pipes just hasnt been able to get in as floor was being polished Link to comment Share on other sites More sharing options...
PeterW Posted September 15, 2016 Share Posted September 15, 2016 Ok that's not too bad then ! Link to comment Share on other sites More sharing options...
Stones Posted September 15, 2016 Share Posted September 15, 2016 (edited) We have a cold roof - this is how we are doing it: Battens fixed to roof trusses / rafters immediately underneath OSB sarking. This is to prevent the insulation pushing up against or being in contact with OSB and the condensation issues that could arise. The battens ensure a 45mm ventilation gap between insulation and sarking. Another batten fitted to the underside of the truss / rafter so that there is enough depth left between rafters (180 mm) to take 2 x 90 mm frametherm 35 batts. 50 mm board insualtion across the rafters, joints taped and foamed. We have taken our insulation right down to the wall plate (it actually extends out over all the EWI we have) There will be further battens on top of the insulation boards to create a small service cavity then plasterboard. A large part of our roof is vaulted, so no truss uprights to worry about, but where we have them they will have nothing more than plasterboard as they are within the insulated envelope. The gap through you can see leads to a section of the house with normal ceilings. This area will have 450mm earthwool, which will simply be brought up to the back of the frametherm batts. Just to clarify, the area you are asking about is cold roof? Edited September 15, 2016 by Stones Link to comment Share on other sites More sharing options...
ProDave Posted September 15, 2016 Share Posted September 15, 2016 I would take the Frametherm and Celotex topping all the way down in the habitable bit of the roof, thus insulating the voids. Then no need to insulate them as well and it gives you a warm storage space if you care to put a couple of trap doors in. 1 Link to comment Share on other sites More sharing options...
janedevon Posted September 15, 2016 Author Share Posted September 15, 2016 I get so,confused over warm roof cold roof, the area im insulating,is as im led to believe a warm roof ie open to habitable rooms was advised to not bother with batten and could insulate up to sarking as a breathable membrane is being used, the area beyond where all the ducting is going, is what i thought a cold roof so boarded below and will have 2 huge layers of rockwool over rafters before boarding. see how easily im confused is your roof space habitable? And why is it a cold roof not a warm one lol Link to comment Share on other sites More sharing options...
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