Clearances Required Between Damper Sleeves & Wall/Floor Openings
There is no minimum clearance requirement between the wall/floor opening and the sleeve exterior (with thermal
blanket attached). However, to facilitate installation, clearances between the wall/floor opening and the damper
sleeve are recommended. Although there is no maximum allowable clearance, the minimum overlap requirements
between the wall/floor and the flange/retaining angle must be met. On grill mount installations the flange must
overlap the wall/floor by
1
⁄
2
in. (13 mm). On continuous duct installations the retaining angles must overlap the
wall/floor by 1 in. (25 mm). Note that the dampers may not be installed within the plane of the wall using this
installation method.
Wooden Stud Construction
Gypsum Wallboard
Stud or Runner
In wood stud construction,
gypsum wallboard must cover
all wood stud surfaces.
#10 sheet metal screws, 2 1/2
inches long, spaced 6 in. on center
and maximum of 2 in. from corners
(minimum of 2 screws per side).
Screw into rear portion of the studs
so as to avoid space conflicts with
the grille assembly.
Figure 3 - Wood Stud
Steel stud
Flange
#10 2 1/2 in. long sheet metal
screws spaced 6 in. on center and
maximum of 2 in. from the corners
(minimum of 2 screws per side)
through the sleeve into the header,
sill and jamb framing members.
Screw into rear portion of the
studs so as to avoid space
conflicts with the grille assembly.
Figure 4 - Metal Stud
Out of Wall Fire and Combination Fire Smoke Dampers
4
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