Lobster wrote:
Chris Bacon wrote:
Lobster wrote:
The whole point of 'heeling and toeing' is to firmly wedge the
glass sealed unit within the opening part of the window frame, to
PREVENT what might be termed 'settling'... the idea is that the
sealed unit is rigidly mounted to the window frame, bit like a
splint, to stop it from distorting. A uPVC frame without a sealed
unit is very weak, and can easily distort several mm in any
direction, certainly enough to prevent the window from closing in the
future. Heeling and toeing is always done with the window closed, so
the frame is 'fixed' in the correct position.

But this is all wrong! The glazing panel *must not* be used as a
structural component, as this will cause premature failure.

Are you disgreeing that the sealed unit imparts stiffness to the opener
(ie, and is intended to do so?)??

I am not disagreeing that the unit can impart stiffness (or rigidity) -
however, normal ones are not intended to do this. There may be units
that are.