In article ,
Tim Streater wrote:
But in our case it was a standard 1930s build brick cavity wall. A uPVC
DG unit is quite heavy, myself I'd worry somewhat about whether your
wooden frame structure will flex too much in use.

As I said, there will be 5mm clearance each side and top/bottom. A decent
flexible sealer should be able to cope with that. There's not quite the
same need for a very strong fixing as most external doors since there's
little in the way of a security issue.

--
*El nino made me do it

Dave Plowman London SW
To e-mail, change noise into sound.