Use permanent packers below jambs and any mullions to ensure the weight of the element can be absorbed by the underlying structure (A).
Packing at the head of the jamb (B) can ensure better window operation. Place permanent packers at hinges and locking points to provide better protection against forced entry.
The cill must be straight and level. It can under no circumstances bend up or down.
Jambs must be plumb.
Diagonal measurements have a tolerance of no more than ±2 mm.
Permanent wedging at the frame head may only be used if the load from any window/door unit above does not subject the frame profile to stress apart from at the jambs and mullions.