Re: Wood casings on vinyl windows
on the outside or inside, you need to give more info in you questions
i do it all the time though on the outside.. when siding homes with either wood or fibre cement siding.
if the window has nailign flange it should be sealed with 4" vycor or bluskin, working your way from the sides then across the top. from there you have to plough out the trim to allow for the thickness of hte nailing flange on the back. this will allow the trim to lay flat on the wall. from there install the trim and back caulk everything. once all the wood is on you will have to bend up some aluminum and install a cap flashing which will seal the top edge of the trim then the flashing goes up the wall but behind the siding and housewrap
fire up the saw and make some dust