Thorfun

this is exactly what I was going to ask! I remember @ProDave saying that 25mm battens plus the 12mm plasterboard fits a 38mm backbox perfectly. am I misquoting you Dave? But I also note that many others have used 38mm x 50mm battens. as an electrician @ProDave which is best (or your preference) and why?

Internorm, Norrsken, Gaulhoffer, Idealcombi and Rational. there are so many companies that some got cut just coz we didn't like the pushy salesman. others just coz we'd had enough of walking around a show! not very scientific and we may have missed a potential gem but we just couldn't visit them all.

if that's aimed at me, then we found the Velfac windows just didn't feel solid when opening and closing. but everyone sees things differently so, seeing as windows are a very big ticket item normally, the best advice I can give is to go and see LOTS of window companies. the big shows are a great way to see the majority but then there are others that don't go to the shows so a visit to the company/reseller is required. we must've visited/seen at least 10 different window companies and 'tried' them out at shows before whittling our choice down to 5 or 6 that we got quotes from.

we saw Velfac at a show and discounted them early on as we didn't think they felt that good quality. might just've been us though I guess but, in my opinion, Norrsken are vastly superior quality but I am a bit biased seeing as we bought Norrsken! ?

cheers @nod. great info as usual.

thanks for this alternative option @nod! but it has raised a few extra questions. 1. how thick would the adhesive need to be? i.e. how much more of the frame would be 'lost' by sticking the PB on? 2. what would your preference be if you turned up to a job? the batten solution that @pocster used or the flush PIR and sticking the PB? 3. what adhesive would be best in this situation to use when considering that there will be an AVCL on top of the PIR so the PB will actually be sticking to that?

it's EPS300. our SE said the thickness didn't matter as long as it was EPS300. so I did the calculations and decided that 300mm EPS just gave a stupidly low U-value and the 200mm was sufficient for our needs so decided to save some money. the PIR was just something to staple the UFH pipes to! it was cheaper to use that than to pay for more screed and click tracks for the UFH pipes. we're going for 190mm Frametherm 32 between the rafters and 100mm PIR (maybe 90mm, I will revisit those calculations in due course) below the rafters. UFH on the ground floor and basement but don't ever anticipate using the UFH in the basement. I am really not worried about heat loss tbh, but I see a thermal bridge and try and resolve the issue. the curse of a mind that troubleshoots for a living! pi$$es the wife off no end as every time she talks to me about something I have to find a solution to it.

are we playing basement top trumps again? ? 200mm EPS below basement slab with 25mm PIR on top of slab under the screed and 200mm EPS outside basement walls. for areas above ground that don't have the basement underneath we have 300mm EPS under slab. 140mm Frametherm 32 between the studs and 80mm PIR inside the studs.

yep. and timber isn't a bad insulator anyway.

still a bit of a cold bridge there though through the timber frame stud, into the batten and then in to the house. but I guess there'll be AVCL on top of that all anyway so I wonder how much of an impact that bridge will have

summin' like this? as is at the moment: with a 25mm x 50mm batten: with PIR: I could then add some 25mm PIR between that batten and the corner batten like this?

yeah. sorry. on the front of the PIR will be AVCL and service cavity with battens. but I'm not sure about on the side? how does one attach plasterboard to the PIR there?

cheers. I thought it might come down to personal preference so I'll ask SWMBO. don't want to end up like @Adsibob and I presume it's ok to screw PB into the side of the PIR? it's not like it's going to split like screwing in to the end grain on wood?

Hi all, I'm not far off starting our internal PIR insulation and have a quick question as to what's the best way to install it against the windows, flush or a gap? e.g. Flush: a gap: obviously, flush reduces the cold bridge but after adding AVCL and tape and plasterboard and a skim would that take a stupid amount off the profile of the window? whereas by leaving a gap for the plasterboard to sit would allow more of the window frame profile to be visible. or is there a better way? or is it simply personal choice as to how much window frame you want showing? any advice is greatly appreciated.

yeah. definitely easier on a new build rather than renovation. but if you're having the roof re-tiled then it makes it easier (and potentially cheaper on not having to use tiles under the panels).

we used arbtech. very happy with their service and prices.

yeah.....we're aware ?

this self-building stuff has ruined me too as for years I told my wife what 12 inches looks like and now she's confused about timber sizes etc.

here's my install. so much nicer than on-roof!

this is correct. we have Norrsken windows and are very happy with them but they are made by Viking windows. personally I would highly recommend Norrsken.

I'll need to borrow your tape measure first, to make sure I measure it up correctly. ?

for me to know and you to find out on crime watch in about 20 years (that's a joke by the way before anyone tries to track me down to call the police! it's really going to be used for music room, cinema, golf studio and games room for the kids)

none.

just plasterboard over it. a real dungeon doesn't need light.

I don't know how much man made costs as I never even thought about using them but good natural slate doesn't have to break the bank! we paid around £1.30 per slate for Spanish slates from Jewsons (Mont Azul Lombeiro slates). personally I think they look fantastic and our roofer said they were really good to work with.