Greenheck G/GB (471558) - Manual (Page 6)

Downblast Centrifugal Roof Exhaust 6
®
Roof Curb
Model GPF, GPFHL,
GPFHD or Equivalent
18 ga. min.
High wind ratings – 42 in. Tall Max
Seismic ratings – 24 in. Tall Max
Steel Welded Construction
Curb Corner
Anchor Detail
1¼ in.
(32 mm)
1¼ in.
(32 mm)
Fan to Curb Mounting
5/16-inch self-drilling fasteners are to be installed on
each side of fan with one fastener 4 inches from each
edge and one fastener in the center. Fasteners are to
be equally spaced.
Curb to Deck Mounting
Fasteners need to be located on all four sides of the curb.
Mounting for Severe Duty Installations
High Wind Ratings
Fan
Size
Curb Cap Size
Self-Drilling
Screw Size
Fasteners
Per Side
Total
Fasteners
Concrete
≤ 141
17x17 to 22x22
(432x432 to 559x559 mm)
3/8”
3 12
> 141
26x26 to 40x40
(660x660 to 1016x1016 mm)
3 12
Steel
≤ 141
17x17 to 22x22
(432x432 to 559x559 mm)
1/4” - 14
3 12
> 141
26x26 to 40x40
(660x660 to 1016x1016 mm)
4 16
Timber
≤ 141
17x17 to 22x22
(432x432 to 559x559 mm)
3/8”
3 12
> 141
26x26 to 40x40
(660x660 to 1016x1016 mm)
4 16
All dimensions are in inches (millimeters).
Roof Curb Roof Curb
1/4 in. - 14 Self-Drilling Screw
Min. 1/2 in. (13 mm) of Threads Through
Roof Truss
1/8 in. (3 mm) Thick
or 12 ga. Min.
3/8 in. (10 mm) S.S. Hilti Kwik Bolt
Three Expansion Anchors
Min. 2-1/2 in. (64 mm) Engagement
2500 Min. PSI
Concrete
Concrete
Deck Anchoring
Steel
Deck Anchoring
Timber Anchoring
Roof Curb
Wood Timber
Min. 4 in. (102 mm)
Nominal Thickness
Min. G = 0.42
G: Specific Gravity
of Lumber
3/8 in. (10 mm) Lag Bolt (Zinc Plated)
Min. 3 in. (76 mm) Thread Engagement
Fan Size
Fasteners
Per Side
≤ 163 3
180 to 240 5
≥ 260 9
Seismic Ratings
Fan Size
Fasteners
Per Side
Total
060-300 2 8
330-540 3 12
060-300 2 8
330-540 3 12
060-300 2 8
330-540 3 12
NOTE: Installation instructions for seismic ratings are only
recommendations.
Final design must be determined by Structural Engineer
of Record (SEOR) including requirements for curb
construction, mounting of unit to curb and mounting of
curb to structure.