UPVC Window Sealing

[CJPR7676]

Hi folks,

Can somebody kindly advise?

Having just gone up the ladder to do a bit of paintwork I've noticed that there is a gap beneath the UPVC frames where they sit on top of the stone windowsills
Should there be sealant in these and if so what should I use, No More Big Gaps?

Cheers,

Chris

 

[Gazman16]

ideally a bit of expanding foam under there first as the gap is a bit big.
If you foam it masking tape everything as it will go everywhere especially from the cheap diy cans!
Once th foam has set dig it out about 5mm back from the edge and seal with "low modulus neutral cure silicone" (LMA for short)