Fasten The Door Bracket - Chamberlain 3275 Owner's Manual

INSTALLATION STEP 11

Fasten the Door Bracket

Follow instructions which apply to your door type as
illustrated below or on the following page.
A horizontal reinforcement brace should be long enough
to be secured to two or three vertical supports. A vertical
reinforcement brace should cover the height of the top
panel.
Figure 1 shows one piece of angle iron as the horizontal
brace. For the vertical brace, 2 pieces of angle iron are
used to create a U-shaped support. The best solution is to
check with your garage door manufacturer for an opener
installation door reinforcement kit.
NOTE: Many door reinforcement kits provide for direct
attachment of the clevis pin and door arm. In this case you
will not need the door bracket; proceed to Step 12.
SECTIONAL DOORS
1. Center the door bracket on the previously marked
vertical centerline used for the header bracket
installation. Note correct UP placement, as stamped
inside the bracket.
2. Position the top edge of the bracket 2"-4" (5-10 cm)
below the top edge of the door, OR directly below any
structural support across the top of the door.
3. Mark, drill holes and install as follows, depending on
your door's construction:
Metal or light weight doors using a vertical angle
iron brace between the door panel support and the door
bracket:
• Drill 3/16" fastening holes. Secure the door bracket
using the two 1/4"-14x5/8" self-threading screws
(Figure 2A).
• Alternately, use two 5/16" bolts, lock washers and nuts
(not provided) (Figure 2B).
Metal, insulated or light weight factory reinforced doors:
• Drill 3/16" fastening holes. Secure the door bracket
using the self-threading screws (Figure 3).
Wood Doors:
• Use top and bottom or side to side door bracket holes.
Drill 5/16" holes through the door and secure bracket
with 5/16"x2" carriage bolts, lock washers and nuts
(not provided) (Figure 4).
NOTE: The 1/4"-14x5/8" self-threading screws are not
intended for use on wood doors.
HARDWARE SHOWN ACTUAL SIZE
Self-Threading
Screw
1/4"-14x5/8"
Fiberglass, aluminum or lightweight steel garage doors
WILL REQUIRE reinforcement BEFORE installation
of door bracket. Contact your door manufacturer for
reinforcement kit.
Header
Bracket
Door
Bracket
Location
Vertical
Centerline
of Garage
Door
Figure 1
Vertical Reinforcement
Vertical Centerline
of Garage Door
Door
Bracket
Self-Threading
Screw 1/4"-14x5/8"
Figure 2A
Vertical
Centerline
of Garage
Door
UP
Self-Threading
Screw
1/4"-14x5/8"
Figure 3
19
HORIZONTAL AND VERTICAL
REINFORCEMENT IS NEEDED
FOR LIGHTWEIGHT GARAGE
DOORS (FIBERGLASS,
ALUMINUM, STEEL, DOORS
WITH GLASS PANEL, ETC.).
(NOT PROVIDED)
Vertical Reinforcement
(Not Provided)
Vertical
UP
Centerline
of Garage Door
Bolt
5/16"-18x2"
Door
Bracket
Lock Washer 5/16"
Figure 2B
Inside Edge of
Bolt 5/16"x2"
Door or
(Not Provided)
Reinforcement
Board
Vertical
Centerline
of Garage
Door
UP
Nut
5/16"-18
UP
Figure 4