saulgalloway Posted February 25, 2021 Share Posted February 25, 2021 Hi, sorry to steam right in with a question, but tbh it's why I joined the forum to pick your collective brains! About 1/2 way through a deep refurb of a bungalow, all that was left was the walls and I wish I hadn't, but had had such a bellyful of planning in AONB and green belt that I couldnt face going back to argue for a complete rebuild application. The existing walls are atypical, 220mm thick, 85mm light block, 50mm empty unventilated cavity, 85mm light block. for simplicity I've treated this as a flat laid solid 215mm aircrete block. The wall build up from outside in will be silicone render, 150mm graphite EPS, 220mm existing wall, 0.5mm aluminium foil membrane (vapour barrier), 25mm PIR, 12.5mm plasterboard and 3mm skim. I'm planning on Internorm HF410 windows which have a potential U of 0.64 but I have to stick to 3 sashes in 1.8m windows so will be a bit worse worse than that with more frame/mullion and less glass. I've attached images of the proposed window mounting outrigged in the EPS. I had thought to line out the rough window opening with 50mm celotex or similar on all 4 sides of the rough opening and hang the window out in the external insulation EPS with brackets. I thought that if I ran a chunky sub sill of PIR/PUR under the window I could screw and plate that external to the wall to support the majority of the window weight. The bottom brackets could be L shaped and run down the inner wall face to resist any tendency to "turn out" the bottom course of block? Suggestions / critique gratefully received. 1 Link to comment Share on other sites More sharing options...
saulgalloway Posted March 3, 2021 Author Share Posted March 3, 2021 Bump, any thoughts? Link to comment Share on other sites More sharing options...
ProDave Posted March 3, 2021 Share Posted March 3, 2021 Don't set the window out quite that far. Our situation is slightly similar, 200mm insulated timber frame with 100mm wood fibre board external insulation and similar render. The windows were bought with aluminium external cills iirc about 130mm deep. So the windows were set so the cills overlapped over the wood fibre board enough to allow for the render. Some pictures to explain it: Here is how the window sits in relation to the wood fibre board, so the windows sits partly in the timber frame (brick wall in your case) and partly in the external insulation (EPS in your case) The windows are fixed with several galvanised plates pre drilled with holes (someone will tell your the correct name?) first screwed to the windows then screwed to the frame (again that will be screwed to your brick walls) Link to comment Share on other sites More sharing options...
will_k Posted March 3, 2021 Share Posted March 3, 2021 We have very similar wall build up & had 150mm EWI We made plywood boxes to line the rough openings & project into EWI layer about 70mm For the larger windows we screwed a block of compacfoam to the external wall to add additional support, but not sure it was neccessary.. plywood boxes themselves were very ridged once screwed & foamed in. Additional benefit of air tightness taping being really straightforward 2 Link to comment Share on other sites More sharing options...
Russell griffiths Posted March 3, 2021 Share Posted March 3, 2021 Compac foam do a system fo fixing windows into EWI it consists of very rigid insulation that carries the window load. Charlie Luxton used a fibreglass angle section that was screwed to his framing that projected out into the EWI, the window then sat on this angle and the insulation butted up to it completely hiding it. Link to comment Share on other sites More sharing options...
LiamJones Posted October 8, 2023 Share Posted October 8, 2023 Hi @will_k can you remember how thick the ply was for these? Any tips on how to do the plywood boxes? How'd you fix them? what about the cavity and lintels? I'm about to do something similar, inspired by this, so thank you! Cheers, Liam Link to comment Share on other sites More sharing options...
will_k Posted October 20, 2023 Share Posted October 20, 2023 On 08/10/2023 at 14:04, LiamJones said: cavity HI, standard 18mm exterior ply, concrete screws into inner and outer leaf of cavity wall, and into conrete lintels IIRC Link to comment Share on other sites More sharing options...
LiamJones Posted May 21 Share Posted May 21 Hey @will_k back again with another question! Did you run the EWI up to the ply, or did you then run ~80mm over the top of the ply and window frame to create an EWI reveal? Struggling with this detail atm. Link to comment Share on other sites More sharing options...
ClairedM Posted June 20 Share Posted June 20 Don't suppose you have the Internorm standard guidelines/recommendations that you could send to me? Link to comment Share on other sites More sharing options...
ClairedM Posted June 20 Share Posted June 20 Don't suppose you have the Internorm standard guidelines/recommendations that you could send to me? Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now