Chamberlain 3255-2M 1/2 HP ユーザーズマニュアル

INSTALLATION STEP 2

Install the Header Bracket

You can attach the header bracket either to the wall

above the garage door, or to the ceiling. Follow the

instructions which will work best for your particular

requirements.

DO NOT install the header bracket over

drywall. If installing into masonry, use concrete

anchors (not provided).

WALL HEADER BRACKET INSTALLATION
• Center the bracket on the vertical centerline with the

bottom edge of the bracket on the horizontal line as

shown (with the arrow pointing toward the ceiling).

• Mark the vertical set of bracket holes (do not use the

holes designated for ceiling mount). Drill 3/16" pilot

holes and fasten the bracket securely to a structural

support with the hardware provided.

Lag Screw
5/16"-9x1-5/8"

HARDWARE SHOWN ACTUAL SIZE

Lag Screws
5/16"-9x1-5/8"

Optional

Door Spring

Header

Bracket

2x4
Structural
Support

Vertical
Centerline of
Garage Door

Horizontal
Line

Wall Mounting Holes

Highest Point of
Garage Door Travel

Wall Mounting Holes

CEILING MOUNT ONLY

The nail hole is for positioning
only. You must use lag screws to
mount the header bracket.

Header Wall

Garage Door

Ceiling Mounting Holes

CEILING MOUNT ONLY

Lag Screws
5/16"-9x1-5/8"

Garage Door

– Finished Ceiling –

– Header Wall –

Header

Bracket

6" (15 cm)
Maximum

Door
Spring

Vertical
Centerline of
Garage Door

The nail hole is for positioning
only. You must use lag screws
to mount the header bracket.

CEILING HEADER BRACKET INSTALLATION
• Extend the vertical centerline onto the ceiling as shown.
• Center the bracket on the vertical mark, no more than

6" (15 cm) from the wall. Make sure the arrow is

pointing toward the wall. The bracket can be mounted

flush against the ceiling when clearance is minimal.

• Mark the side holes. Drill 3/16" pilot holes and fasten

bracket securely to a structural support with the

hardware provided.