Closing cavity around window opening before fitting

fclauson

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ExtaticFob

Hi all. Looking for some advice as a first time self builder who may have made a bags of cavity closing around our windows. Keeping it short, we have our cavity fully filled with 150mm insulation and windows are in. We don’t have cavity closets installed. We do have the gap filled with expandable foam. Question is, do we need to take the windows out to put the closers in? I’ve attached pics. Any help / advice greatly appreciated.

fclauson

can we have a pic from the outside too

expanding foam is not airtight - what air tightness are you going for

ExtaticFob

fclauson wrote: »

can we have a pic from the outside too

expanding foam is not airtight - what air tightness are you going for

Thanks for the reply. We’re going to be taping inside with air tightness tape. We’re also putting an insulated board on it. That might not answer your question but there’s a lot of learning as we go. Requested photo attached.

fclauson

ExtaticFob wrote: »

Thanks for the reply. We’re going to be taping inside with air tightness tape. We’re also putting an insulated board on it. That might not answer your question but there’s a lot of learning as we go. Requested photo attached.

Ok - see my tech arch picture further back in this post
you need to look at how you are going to make it
a) insulated correctly with no cold bridge around the window (this will require thermal modelling probably)
b) airtight

if you fail on (a) you could end up with a cold bridge (read mold) around the wind frame on the window return because the wall/frame fall below the threshold temp

read about FRSI in the (google FRSI calculations)

ExtaticFob

fclauson wrote: »

Ok - see my tech arch picture further back in this post
you need to look at how you are going to make it
a) insulated correctly with no cold bridge around the window (this will require thermal modelling probably)
b) airtight

if you fail on (a) you could end up with a cold bridge (read mold) around the wind frame on the window return because the wall/frame fall below the threshold temp

read about FRSI in the (google FRSI calculations)

I’ll check that out. Thanks again. In your experience is there a way around this without removing the windows? As well as the inconvenience, we are getting the external wall plastered from tomorrow.

BryanF

ExtaticFob wrote: »

I’ll check that out. Thanks again. In your experience is there a way around this without removing the windows? As well as the inconvenience, we are getting the external wall plastered from tomorrow.

It’s jot clear if there is a DPM/EPDM folded out over/down side of the windows etc?
Did your eng/arch do a detailed drawing done