Figure 3 – Greenheck Grille Installation Supplement (463622) User Manual

Page 2

Grille Installation Supplement Rev 5 January 2013

2. Retaining Angle Method

Damper/sleeve assemblies must be installed in wall
and floor openings using retaining angles on at least
one side of the wall or floor as described below:
• Retaining angles for 11/2 hour rated dampers with a

width and height 48 in. (1219mm) or less must be
a minimum of 20 ga. (1mm). Retaining angles for
all 3 hour rated dampers and all dampers with a
width or height greater than 48 in. (1219mm) must
be a minimum of 16 gauge (1.5mm). The leg of the
retaining angle on the damper sleeve shall be a
minimum of 11/4 in. (32mm). The leg of the retaining
angle on the wall/floor shall be long enough to cover
the annular space and overlap the wall/floor by a
minimum of 1 in. (25mm)(see Figure 3).

• For grille installation on fire damper up to 36 in.

x 36 in. (914mm x 914mm) maximum, angle legs
may be reversed and one leg inserted into the wall/
floor opening providing the required clearance is
maintained between angle leg fastener and the wall/
floor opening. Note: Screws used to attach grille are
allowed to penetrate reversed angle leg.

• Retaining angles must be attached to the damper

using one or more of the following methods of
attachment (refer to label on outside of sleeve for ‘No
Screw’ area):

• Tack or spot welds

• #10 (3/4 in. [19mm] max.) sheet metal screws

• 1/4 in. (6mm) bolts and nuts

• 3/16 in. (4mm) steel pop rivets

Retaining Angle

(See Section 2)

Damper sleeve

Grille (supplied
by others)

Figure 3

A minimum of two connections per side, top and
bottom, 12 in. (305mm) O.C. maximum. The angles
must be attached to all four sides of the sleeve. Ensure
that attachment device does not interfere with the
operation of the damper and the free movement of the
damper blades. The angles need not be attached to
each other at the corners.
• Retaining angles must be attached to the partition

using one of the methods below (see single side
retaining angle-vertical mount supplement part
#462099):

• Drywall screws of a length such that the

screw engages the steel stud/track by 1/2 in.
(13mm) (steel framing).

• Drywall screws of a length such that the

screw engages the wood stud by 13/4 in.
(44mm) (wood framing).

• Steel anchors or self tapping concrete screws

penetrating masonry or block 11/4 in. (31mm).