Gap around internal UPVC frame

[Apophany]

Hi,

We have some fairly old UPVC windows in a Victorian property which seems to have a pretty large and deep gap in one section of the frame where I can feel a draft. There's some material along the length of it already, not sure if that was done during installation or at a later point, but it's a lot of it is missing. I've attached some pictures, but just want to know what the best way to try and fill it is. I've seen about expanding foam, but I'm not sure how that will end up looking after its been applied, or if I should put something on top of it to finish.

Thanks in advance

 

[Wayners]

Polymer grab.

Ct1 or Ob1 type.

Masking tape either side of gap. Run down getting plenty in.
Finger or tool it.
Pull tape.
Run finger or tool down for final time.
That trim coming off needs polymer grap behind and push back on.
Masking down front to protect plastic from marking and pile up something against to hold back for few hours

 

[Apophany]

Polymer grab.

Ct1 or Ob1 type.

Masking tape either side of gap. Run down getting plenty in.
Finger or tool it.
Pull tape.
Run finger or tool down for final time.
That trim coming off needs polymer grap behind and push back on.
Masking down front to protect plastic from marking and pile up something against to hold back for few hours

Hey thanks for the reply. I'm not sure an adhesive would do the trick, I think that would work for the trim coming off on the window side, but on the wall side where the gap is largest it doesnt seem to be due to it flexing away from the wall, either the gap was like that when the initial installation has happened or something has moved, but there's no way you could push that back against the wall to stick it, also the stuff thats been put in there previously to bridge the gap is quite solid

 

[ronniecabers]

Stuff in there is probably Stelmax . You have two choices , pull of existing trims and retrim ( bearing in mind the trim may be superglued to the window and leave a mess on removal ) ,or reseal with any proprietary caulk/silicone . Those gaps look sealable to me