Securing the Damper/Sleeve Assembly to Wall/Floor Openings
Damper/sleeve assemblies must be installed in wall openings using flanges and sheet metal screws as illustrated
and described below.
• Flange on front (grille end) of sleeve must be a minimum of 16 ga. (1.5 mm) steel and have
5
⁄
8
in.(16 mm)
minimum flange leg (refer to
Figure 8
). Using #10 (19 mm) sheet metal screws, screw from inside of sleeve
through the rear portion of the studs (as shown in
Figures 3 & 4
). Space screws a maximum of 6 in. (152 mm)
O.C. and a maximum of 2 in. (51 mm) from the corners (minimum of 2 screws per side). No retaining angles are
required on the side of the wall opposite from the grille.
• Retaining angles for 1
1
⁄
2
hour rated dampers with a width 48 in. (1219 mm) or less must be a minimum of 20 ga.
(1 mm). The leg of the retaining angle on the damper sleeve shall be a minimum of 1
1
⁄
4
in. (32 mm). 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. (25 mm). See
Figure 9
.
• Retaining angles must be attached to the damper using one or more of the following methods of attachment:
- Tack or spot welds
- #10 (
3
⁄
4
in. [19 mm] max.) sheet metal screws
-
1
⁄
4
in. (6 mm) bolts and nuts
-
3
⁄
16
in. (5 mm) steel pop rivets
Attachments must be spaced a maximum of 6 in. (152 mm) on center and a maximum of 2 in. (51 mm) from corners.
The angles must be attached to all four sides of the sleeve. A minimum of two attachments are required on each
side, top and bottom. The angles need not be attached to each other at the corners.
Caution! Do not tear the thermal blanket during installation.
Horizontal mount: thermal
blanket (installed around
entire outside surface
of sleeve)
Vertical mount: thermal
blanket (installed around
only on the top and sides)
Wall
Flange
Figure 8: Sleeved Damper with Thermal Blanket (duct
termination)
Retaining Angle
2 in. Max.
6 in. Max.
6 in. Max.
2 in. Max.
Wall
Horizontal mount: thermal
blanket (installed around
entire outside surface
of sleeve)
Vertical mount: thermal
blanket (installed around
only on the top and sides)
Figure 9: Sleeved Damper with Thermal Blanket (duct
continuation).
Out of Wall Fire and Combination Fire Smoke Dampers
6
®
