Chamberlain C870C Owner's Manual page 17

HARDWARE
Self-Threading Screw
1/4"-14x5/8"
Header Wall
2x4 Support
Header Bracket
Door Bracket
Optional
Placement
of Door
Bracket
Vertical
Centerline
of Garage
Door
Metal Door
Self-Threading Screw
Top of Door
Door
(Inside Garage)
Bracket
Top Edge of
Door
Optional
Placement
(Finished Ceiling)
For a door with no exposed
framing, or for the optional
installation, use lag screws
5/16"x1-1/2" (not provided)
to fasten the door bracket.
Wood Door
Hardware
(not provided)
Door
Top of Door
Bracket
(Inside Garage)
Top Edge
of Door
Optional
Placement
Hardware
(not provided)