In message , Grunff
writes
Dave Plowman wrote:

Where should such a strip be obtained?

Round here there are numerous 'glasing and conservatory' merchants, who
stock things like polycarb roof, uPVC channel. and finishing strip. Not
sure what they come under in yell, but there must be some round your way.

Alos, Wickes have a variety of PVC profiles/strips.

I stuck my internal ones on with Mitre Fast (basically a two part
Cyanocrylate). In this situation I think would use some white silicon
sealant to bed them down onto (to seal behind and to hold them on)

Thinking about it, we had some UPVC windows fitted last year, IIRC (it's
dark) the fitters used a very dark brown sealant in this situation and
I think that looks pretty neat and tidy.
--
Chris French, Leeds