Chamberlain C870C Owner's Manual page 12

HARDWARE
Lag Screw 5/16"-9x1-5/8"
WALL INSTALLATION
2x4
Structural
Wall Mounting
Support
Holes
UP
Horizontal
Line
Highest Point
Optional Mounting of Garage
Holes Door Travel
CEILING INSTALLATION
Header
Bracket
6" (15 cm)
Maximum
Ceiling Mounting
Holes
Door Spring
UP
Header Wall
Header
Bracket
Garage Door
Finished Ceiling
Garage Door
Vertical
Centerline of
Garage Door
Lag
Screw
Door
Spring
Vertical
Centerline of
Garage Door
Lag Screw
Header Wall