Once the window is secured in place with shims, but before any fasteners are installed, the window should be checked for squareness, plumbness, horizontal and vertical levelness and that all movable parts and locking mechanisms operate properly and freely.
Fasteners
Anodized, or rust protected, screws are the fastener of choice. They should be driven in through the centre of every shim or through the nailing flange if one is supplied.
Once again check to ensure that the window has remained square, level and plumb, and that all movable parts and locking mechanisms still operate properly and freely. At this point cut off the protruding ends of the shims and insulate.
