Conor Posted October 30, 2019 Share Posted October 30, 2019 In a bit of a rub with my architect. We have a 5m wide opening that has 5 panel bi-folds on the ground floor (2700mm) and five fixed panes directly above on the first floor (2200mm). At first floor level there's an open mezz, then a bedroom. I had always assumed there would be a 300mm deep RSJ spanning across and giving somewhere for the bi-folds to hang from, and above fixed panes to sit on. My architect is against this as it would be thicker than the glazing systems and difficult to insulate and therefore a really bad cold bridge. Instead, he's suggesting that the glazing is treated as a single element and designed accordingly by the glazing supplier. And the internal floor slab would be on a seperate, internal beam system behind the mezzanine. Issue is, both bifold door options I'm looking at are top hung and require something solid to bolt in to... So a commercial style glass curtain isn't an option. I'd have to change door systems... I was thinking a price of 300mm X 100mm steel channel. This would allow the bedroom floor slab to be supported as well as the glazing. Just not sure how it would be sufficiently insulated? Anybody have a similar detail? (Please note the 6th panel on LHS on ground floor is gone, total span is 5m on both floors) Link to comment Share on other sites More sharing options...
Russell griffiths Posted October 30, 2019 Share Posted October 30, 2019 Have you had a structural engineer look at this i would be surprised if a 300x100 Chanel will span 5m and support all that glass and a door and a floor not the look your after, but this is what we are doing to hide the 300mm deep concrete beam above our doors. Link to comment Share on other sites More sharing options...
Conor Posted October 30, 2019 Author Share Posted October 30, 2019 Channel idea was plucked out of my head, I'm not a "real" engineer... She's just got the drawings from the architect... But I don't want to go down a road that's going to end up at a sub optimal and expensive end (i.e. the miriad of steels internally to support the mezz and rear bedroom floor) solution when there is a simple one possible. We have the option of constructing an ICF beam that would end up with a 150x250mm concrete core. But then the total thickness would be 300mm with the windows sitting in the middle... Would look rather odd. Link to comment Share on other sites More sharing options...
ProDave Posted October 30, 2019 Share Posted October 30, 2019 Do you have to have bi folds? With this issue and their know air tightness issues, why not consider a pair or even 3 lift and slide doors? I know you can't open it all, but it might solve the issue? Link to comment Share on other sites More sharing options...
Conor Posted October 30, 2019 Author Share Posted October 30, 2019 Just now, ProDave said: Do you have to have bi folds? With this issue and their know air tightness issues, why not consider a pair or even 3 lift and slide doors? I know you can't open it all, but it might solve the issue? Yes. Has to be a 5 panel system. Anything else won't work with the windows on the first floor. We had it drawn up with a 3 panel lift and slide but it really didn't look right. The bifolds I've been looking at have u value of 0.8 and class 4 airtightness and 25 year guranguaranteetee. so I'm not worried about that. (Similar cost to lift and slide doors). Either way, we'd still be left with my architects plan to put in a load of I thermal steel to support the mezz and rear bedroom where in reality a single beam across that span and another joining at 90degrees at the bedroom wall would do everything Link to comment Share on other sites More sharing options...
Russell griffiths Posted October 30, 2019 Share Posted October 30, 2019 again not really what your doing but this is a 250x150 icf beam across the top of our doors. Like in my previous picture we are having an aluminium flashing to cover this on the outside 4 Link to comment Share on other sites More sharing options...
Mr Punter Posted October 30, 2019 Share Posted October 30, 2019 I would do as @Russell griffiths suggests. If the frames are dark with the ali flashing to match it won't stand out. Btw you may want to lose the tiny triangular window in the corner of bed 3. Link to comment Share on other sites More sharing options...
Conor Posted October 30, 2019 Author Share Posted October 30, 2019 @Russell griffiths Do you have more detail on the build up? E.g. where do the doors fit withing the wall? Flashing/ water proofing? Cheers. Link to comment Share on other sites More sharing options...
Russell griffiths Posted October 30, 2019 Share Posted October 30, 2019 We are only just discussing door location with the window co now, I believe because of the width of the frames they will sit towards the front edge of the wall, still needs clarification. As to waterproofing im afraid I won’t be doing anything unusual as I have an 1800mm roof overhang 45degree rain hardly gets near the front of the building Link to comment Share on other sites More sharing options...
Conor Posted October 31, 2019 Author Share Posted October 31, 2019 11 hours ago, Russell griffiths said: We are only just discussing door location with the window co now, I believe because of the width of the frames they will sit towards the front edge of the wall, still needs clarification. As to waterproofing im afraid I won’t be doing anything unusual as I have an 1800mm roof overhang 45degree rain hardly gets near the front of the building Thanks Russell. So I'm guessing as the doors/windows will be predominantly on the concrete core, the insulated part of the form wil project out ~50mm or so, just like in a standard wall build up. Ours are quite exposed, so will need some sort of sill / damp proofing. Link to comment Share on other sites More sharing options...
Conor Posted October 31, 2019 Author Share Posted October 31, 2019 Update. Spoke to architect. We're now proposing to run a steel beam just inside the curtain wall, with the base flange extended out 65mm so windows can sit on/under. Will minimise cold bridging as will just need a wrapping of aerogel on the beam flange. Now off to the SE for her thoughts. Link to comment Share on other sites More sharing options...
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