On Mon, 16 Jan 2012 16:45:48 -0000, Cash wrote:

They may have got confused ext v int cills. I can see that fitting
a
new fram onto existing external timber would be interesting.

I quite agree there, especially as the cill on a timber window usually
forms and integral part of the frame.

I reckon you could do it but you have to remove the sides from the
cill some how which would probably mean removing the entire cill and
you'd have to make good the ends of the cill from the jointing
somehow. Though that would be coverd by the new uPVC frame sitting on
top. A lot of work.

I've tried using filler between plaster and frame but ulitmately ended
fitting small section, plastic architrave to hide the joint.

What was the problem? I hate stuck on trim bits. I'd fill a large gap
(5mm) with with plaster/polyfilla and expect a crack to appear
between it and the frame, I'd then fill that with decorators chaulk,
that allows for the small movements without cracking. If the orginal
gap was small it would be straight in with the decorators chaulk.

--
Cheers
Dave.