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Windows & Door fitting

Thermal bridging of 3G Aluminium windows

Anonymous user 09/03/2024 - 2.31 PM

I am project managing a build. It's close to passive house standard ( Air tight, MVHR and highly insulated), but the client could not afford timber/alu windows, We are both aware that Aluminium inside and out is a slight compromise. The slate cills have been bedded with the mortar coming under the windows above the DPC. This is already a Thermal/cold bridge but the plan is now to insulate from the inside. the windows are sat on this but the window contractors have fixed the windows with a 1mm- 0mm gap and have not foamed or siliconed the joins, is this normal? or should they have used PU foam, foam tape or silicone?

Are you a tradesperson and able to answer this question?

1 Answer

Anonymous user

I am assuming that they have used direct fix aluminium profile, as opposed to ali into timber, if you look in the profile you may well see a black vulcanized strip, this is the thermal break, if not then the cold will bridge to the inside. anglian windows once used a profile that had a UPVC internal cladding to the ali to get over the problem, or, are you talking about a gap round the window profile to the internal reveal, if so, then a foam, or foam tape would not nessasarily of been benificial, it is hard to say without actually seeing it.

Answered15 June 2015