Exterior Window trims redecorate/ replace

[Grizza]

Hi. Not for the first time water gets behind the trims and starts rotting them so I need to repair / fill before I can paint. I've replaced some with new wood in the past but this time I was thinking of using uPVC like this : -http://store.eurocell.co.uk/window-finishing/trims-quadrants-and-angles1/20x15-bead-64-x-5m.
I've used an acrylic sealant against the glass which is paintable. Will that work with uPVC?

I think I shouldn't be nailing them to allow for expansion and probably just using 'never nails' type adhesive.

Anyone foresee problems or think it's a bad idea please?

 

[Harbourwoodwork]

Hi. Not for the first time water gets behind the trims and starts rotting them so I need to repair / fill before I can paint. I've replaced some with new wood in the past but this time I was thinking of using uPVC like this : -http://store.eurocell.co.uk/window-finishing/trims-quadrants-and-angles1/20x15-bead-64-x-5m.
I've used an acrylic sealant against the glass which is paintable. Will that work with uPVC?

I think I shouldn't be nailing them to allow for expansion and probably just using 'never nails' type adhesive.

Anyone foresee problems or think it's a bad idea please?

My instinct would be to use wood on wood ,seal with traditional putty,prime before you putty it will last for ever,