heat loss around upvc windows

[JamesA]

To avoid heat loss between the upvc window frames and the walls, is it just a case of totally filling the gap?

Is there any significant difference in terms of heat loss in what you use?
Or is just stopping the air infiltration good enough?

We had dodgy window installers who hid everything with trim.
In places the gap is wide enough to get you thumb in, although it was probably like that with the previous windows.

They didn't fill the gaps.
The silicon job outside and in was poor, letting in drafts.

 

[crank39]

Trims are a nessesary evil sometimes, as an ex fitter myself anything that big should be plastered. Its difficult to give an opinion on someone elses fitting as we all work in different ways but a bodge is a bodge which ever way you look at it. It all depends on you decor, if it was damaged during removal so trim may have been the only choice. You have an option of usin expanding foam in all the gaps you can see (inside and outside) or plaster, removing the silicone outside and re-sealing is the easy part

 

[noseall]

Glass = heat loss, full stop.

Aside from this though there are mitigating factors that can exacerbate the problem. Draughts can be a big problem.

If the windows and doors are correctly sealed inside and out then heat loss will be kept to a minimum regardless of gaps. God working practice however (robust details) says fill all gaps with either mortar, plaster, silicone or foam.

It is also very important (and often overlooked by fitters) that the external and internal leaves of masonry are isolated by the frames.

 

[peter1450]

It is also very important (and often overlooked by fitters) that the external and internal leaves of masonry are isolated by the frames.


Noseall, could you expain what you mean by this in simple terms (so i can understand whats required)