What is the difference between pre-assembled and knock-down?

Pre-assembled doors arrive as a complete hung unit with sub-frame and hardware. Knock-down doors ship boxed with the frame in parts – cheaper to ship, a little more work on site.

Pre-assembled walk doors for metal buildings

Made for the girt system

A steel building does not have a masonry wall to anchor into – it has girts and sheeting. The pre-assembled walk door arrives with its own steel sub-frame and girt attachments, so the crew sets the unit in the framed opening, bolts it to the girts and flashes it to the sheeting. Field installation usually takes under 30 minutes.

Because the opening is built into our steel buildings, World Steel details the framed opening, the girts and the door together – the right size, in the right place, on the first day.

Specification

Pre-assembled range
Size	Leaf	Frame	Hand	Lock prep	Astragal
3070	20 or 18 ga	16 ga	Non-handed	161, ASA strike	–
4070	20 or 18 ga	16 ga	Non-handed	161, ASA strike	–
6070 pair	20 or 18 ga	16 ga	Non-handed	161, ASA strike	Z-astragal

Galvannealed steel, polystyrene core (polyurethane optional), 1¾ in
Bolted corners, steel sub-frame with girt attachments
7 ga hinge and 12 ga closer reinforcements, lock box construction
4½ × 4½ in ball bearing hinges, non-removable pins, silver powder coat
5 in × ½ in aluminium saddle threshold, ADA compliant
Kerf and sweep weather seals, detachable flashing

Hand and swing

Metal-building walk doors usually swing out (reverse hand) so wind pressure pushes the door into the stops. The leaf is non-handed and the frame is set for the hand on site.