"Pet @ www.gymratz.co.uk ;¬)" wrote:


Well.... We have the same problem. My brother out-law is a window
fitter and sent half a dozen trickle vents to us. Didn't say it would
present any problems, and the vents on our UPVC patio doors in the
bedroom are fitted to the top of the door part rather than the frame
part.



The vents in your patio door were probably fitted in the factory, so
the reinforcement would be cut before insertion.


This is where I am going to put ours, as and when I can get round to
it. Looking around other houses in the area, they are all fitted to
the "window" rather than the frame.



A retro-fit into the top of a side-hung opening sash might be OK
because it is unlikely to wide enough to require reinforcement. A
profile less than 60mm could be too slim for the vent.
A (well made) top-hung sash more than 750mm wide will have steel in the
top.


--
"S'ils te mordent, mords-les"