ICC-ES Evaluation Report
ESR-1792
Click here to access the UL certification
Reissued December 1, 2013
This report is subject to renewal January 1, 2016.
www.icc-es.org | (800) 423-6587 | (562) 699-0543
A Subsidiary of the International Code Council ®
ICC-ES / UL Dual Report
DIVISION: 07 00 00—THERMAL AND MOISTURE
PROTECTION
Section: 07 44 53—Glass Fiber—Reinforced
Cementitious Panels
REPORT HOLDER:
UNITED STATES GYPSUM COMPANY
550 WEST ADAMS STREET
CHICAGO, ILLINOIS 60661
(312) 436-4260
www.usg.com
[email protected]
EVALUATION SUBJECT:
Concrete Panels are nominally 3/4 inch (19.1 mm) thick,
4 feet (1219 mm) wide, and 8 feet (2428 mm) long with
tongue-and-groove edges. Based on tests in accordance
with ASTM E136, the panels are noncombustible. The
panels yield a flame-spread index of 0 and a smokedeveloped index of 5 or less when tested in accordance
with ASTM E84.
3.2 Floor Framing:
Floor framing, web stiffeners, and blocking must be coldformed from steel complying with AISI-General, with a
minimum 43 mils (0.0428 inch or 1.09 mm) base-metal
thickness (No. 18 gage) and a minimum G60 galvanized
coating. The attachment flange or bearing edge must be at
least 1.625 inches (41 mm) wide.
3.3 Fasteners:
STRUCTO-CRETE™ STRUCTURAL CONCRETE PANELS
1.0 EVALUATION SCOPE
Compliance with the following codes:
 2012, 2009 and 2006 International Building Code® (IBC)
 2012, 2009 and 2006 International Residential Code®
(IRC)
Properties evaluated:
 Structural
 Combustibility
 Fire propagation
2.0 USES
STRUCTO-CRETE™ Structural Concrete Panels are
noncombustible, cementitious floor sheathing panels used
as combination subfloor and underlayment or as subfloor
only. Installation must be limited to weather-protected,
interior locations.
STRUCTO-CRETE™ Structural Concrete Panels are
combined with cold-formed steel floor framing to form a
structural floor system. The floor system is capable of
resisting gravity loads and acting as a horizontal shear
diaphragm, resisting wind and seismic loads.
When used in constructions under the IRC, STRUCTOCRETE Structural Concrete Panels must be designed in
accordance with IRC Section R301.1.3.
3.0 DESCRIPTION
3.1 STRUCTO-CRETE™ Structural Concrete Panels:
STRUCTO-CRETE™ Structural Concrete Panels are
formed from a composite consisting of glass fibers and
cementitious materials. STRUCTO-CRETE™ Structural
The panels must be fastened to the steel floor framing with
self-drilling, self-tapping screws complying with ASTM
C954 and C1513. The screws must be No. 8-18 size
5
[0.164 inch (4 mm) diameter] by 1 /8 inches (41 mm) long
with a minimum 0.36-inch-diameter (9.1 mm) bugle head.
4.0 INSTALLATION
4.1 Design Loads:
4.1.1 General: The floor joists and other floor framing
components must be designed to comply with the strength
and deflection criteria required by the IBC and the project
specifications. Floor framing and structural members
supporting the STRUCTO-CRETE™ Structural Concrete
Panels must be designed to resist the uniform and
concentrated gravity loads specified in Table 1607.1 of the
IBC. The design must determine the framing attachment to
the supporting structure, the layout of the floor sheathing,
and the fastening schedule.
4.1.2 Allowable Uniform Loads: The allowable uniform
loads for the STRUCTO-CRETE™ Structural Concrete
Panels applied over joists spaced 16, 20 or 24 inches
(406, 508, or 610 mm) are shown in Table 1.
4.1.3 Concentrated
Loads:
STRUCTO-CRETE™
Structural Concrete Panels are allowed for occupancies or
uses where concentrated load resistance as required by
Section 1607.4 and Table 1607.1 of the IBC is 1,000
pounds (4.45 kN) or less.
4.1.4 Shear Diaphragm Loads:
4.1.4.1 General: Diaphragm analysis involves the
treatment of the diaphragm as a deep beam. The beam is
assumed to be supported where the diaphragm is
connected directly to the vertical lateral force resisting
system or indirectly by means of a collector or drag
member.
ICC-ES Evaluation Reports are not to be construed as representing aesthetics or any other attributes not specifically addressed, nor are they to be construed
as an endorsement of the subject of the report or a recommendation for its use. There is no warranty by ICC Evaluation Service, LLC, express or implied, as
to any finding or other matter in this report, or as to any product covered by the report.
1000
Copyright © 2013
Page 1 of 7
ESR-1792 | Most Widely Accepted and Trusted
When the forces in a diaphragm are developed from a
wind or seismic event, the distribution of these forces is
typically assumed to be uniform, though nonuniform
distributions are possible depending on how a structure is
configured. The evaluation/characterization of diaphragm
performance must reflect (1) the expected distribution of
forces and (2) methods of construction.
The distribution of internal forces in a simple span
(uniform load) configuration will yield an accurate
representation of the strength and stiffness of the majority
of diaphragm applications. Because the internal distribution
of forces is constant shear along the length of the
diaphragm, the cantilever configuration may yield overly
conservative designs when applied to typical diaphragm
constructions. Design as a cantilever configuration,
however, may be applicable where the diaphragm is more
accurately modeled as a cantilever. Diaphragm
classification as flexible or rigid must be determined in
accordance with Section 1602 of the IBC and Section
12.3.1 of ASCE 7. The diaphragm deflection must be
calculated using the equations noted in Tables 3, 5, or 6 of
this report. Diaphragm deflection limits must comply with
Section 12.2.2 of ASCE 7. Horizontal shears must be
distributed in accordance with Sections 1604.4 of the IBC,
Section 12.8.4 of ASCE 7 and, for Seismic Design
Categories C, D, E and F, Section 12.11.2.2 of ASCE 7.
Horizontal diaphragm length-to-width ratios must be limited
to values set forth in Section 4.2.4 of special design
provisions for wind and seismic (2012 and 2009 IBC) or in
Section 2305.2.3 of the 2006 IBC.
4.1.4.2 Simple Beam Shear Diaphragm Configuration:
Table 2 describes nominal shear values for diaphragms
based on simple beam configurations, which must be
adjusted in accordance with footnote 4 for allowable stress
design or load and resistance factor design. Table 3
provides the corresponding diaphragm deflection
equations.
4.1.4.3 Cantilever Shear Diaphragm Configuration:
Table 4 provides nominal shear values for diaphragms
based on cantilever beam configurations, which must be
adjusted in accordance with footnote 4 for allowable stress
design or load and resistance factor design. Tables 5 and
6 provide the corresponding diaphragm deflection
equations.
4.2 Installation:
4.2.1 General: Installation of STRUCTO-CRETE™
Structural Concrete Panels and framing must be in
accordance with the IBC, this report and USG’s installation
instructions. Copies of this report and USG’s installation
instructions must be available at the jobsite at all times.
4.2.2 Framing: The floor joists must be supported on a
foundation that is uniform and level, or directly by bearing
studs or headers installed at the top of the bearing wall to
distribute the load.
For steel floor joists, web stiffeners must be provided at
reaction points and/or concentrated loads as specified in
the approved plans. End blocking must be provided where
joists ends are not otherwise restrained from rotation.
Additional joists must be provided under parallel
partitions and around all floor openings that interrupt one
or more spanning members. Floor joists must be fastened
to the supporting walls or structure in accordance with the
approved plans.
All blocking or bridging for the steel framing must be
installed prior to the installation of the STRUCTOCRETE™ Structural Concrete Panels.
Page 2 of 7
Framing must be free of bows, twists or other defects.
4.2.3 STRUCTO-CRETE™ Structural Concrete Panel
Application: The temperature during panel installation
must be a minimum of 0°F (18°C) if screw-fastened; or
either a minimum of 40°F (4.4°C) or as specified by the
adhesive manufacturer, if adhesives are used to attach the
sheathing.
As needed, the panels must be cut to proper length and
width in accordance with USG’s installation instructions.
STRUCTO-CRETE™ Structural Concrete Panels must
be installed with the long edges perpendicular to the
framing. Panels may be installed with either surface
against the framing. However, because the panel markings
that facilitate fastening are on one side only, the panels
should preferably be applied with the markings toward the
installer.
As an option, nonstructural, low modulus sealants may
be used in combination with the STRUCTO-CRETE™
Structural Concrete Panels, the floor framing and the
fasteners. United States Gypsum Company must be
contacted to verify whether the adhesive is compatible with
the panels. The structural ratings of the STRUCTOCRETE™ floor/ceiling system described in this report are
based on screw attachment only. Structural adhesives
must not be used where the system is used as a horizontal
diaphragm.
If the specification requires a combined adhesive/mechanical
connection, adhesives must only be applied to the top of
the joists that can be covered by one panel at a time.
Panel installation must commence by snapping a line
across the joists parallel to the rim joist at a distance equal
to the width of the first panel being placed. The floor layout
must be planned so the first and last panel row width is a
minimum of 24 inches (610 mm).
The cut edge or tongue must be placed along the rim
joist. Each panel must be supported across three or more
framing members. Panels must be trimmed to ensure that
the butted ends of each panel are centered on the framing
members. To keep adjacent ends in the same plane,
panels must be placed in a direction that ensures that the
butt ends fall over the open side of the joist.
Each panel must be fastened after placement in
accordance with the fastening schedule specified in the
approved plans and calculations. Fastening must
commence at one end and fan out across the panel, and
corners must not be fastened initially. Fasteners must be
placed sequentially one row at a time. Adjacent panels
must be butted together so that the tongue of one panel
being installed fits into the groove of the installed panel. No
gaps are required between panels. If adhesives or sealants
1
3
are specified in the joints, a /4- to /8-inch-diameter (6.4 to
9.5 mm) bead of adhesive must be applied to the bottom of
the grooves of the installed panels. Sufficient adhesive is
needed to fill the joint that will be covered by the first panel
in the second row. Subsequent panels must be installed in
a similar manner to complete each row. Panel rows must
be placed in a running bond pattern so that end joints fall
over the center of the framing members and are staggered
by at least two framing members from where the end joints
fall in the adjacent rows.
Cut-outs in the panels must be created before installation
of the panels. All cut-out ends and edges exceeding 6
inches (152 mm) in any dimension must be supported by
framing.
Screw fasteners must be installed so the heads are flush
with the panel surface.
ESR-1792 | Most Widely Accepted and Trusted
4.2.4 Floor Finish: Before application of floor finish
materials, all panels must be properly fastened, with the
fastener head driven flush or slightly below the surface of
the panels. All voids and depressions in the panel surface
must be filled with cement-based patching or leveling
compounds. Panel surfaces must be clean and free of
moisture.
Before application of floor finish materials, STRUCTOCRETE™ Structural Concrete Panels must conditioned in
the same environment as required for the finish floors, if
applicable, for at least 48 hours.
Underlayments must be secured to STRUCTO-CRETE™
Structural Concrete Panels with fastenings specified for the
material. Mechanical fasteners must be long enough to
penetrate the STRUCTO-CRETE™ Structural Concrete
1
1
Panels /4 to /2 inch (6.4 to 12.7 mm).
For wood flooring, No. 15 felt or equivalent must first be
laid over the STRUCTO-CRETE™ Structural Concrete
Panels. For engineered wood flooring, the specified
moisture barrier must be used in lieu of the felt. The wood
flooring manufacturer’s installation instructions for
application of wood flooring over the engineered wood
panel floor sheathing must be observed. The STRUCTOCRETE™ Structural Concrete Panels must be kept dry
and maintained in a conditioned space for a minimum of 30
days prior to the installation of wood flooring.
Tackless strips, designed for concrete application, must
be used for the installation of stretched carpet.
4.2.5 Expansion/Control
Joints:
The
design
professional must determine the location and design for
expansion/control joints.
5.0 CONDITIONS OF USE
The STRUCTO-CRETE™ Structural Concrete Panels
described in this report comply with, or are suitable
alternatives to what is specified in, the code indicated in
Section 1.0 of this report, subject to the following
conditions:
Page 3 of 7
5.2 Allowable loads and deflections must comply with this
report.
5.3 Calculations and details justifying that the design
loads do not exceed allowable loads specified in this
report must be submitted to the code official for
approval. The calculations must be prepared by a
registered design professional where required by the
statutes of the jurisdiction in which the project is to be
constructed.
5.4 Design of the building foundation system, walls or roof
is outside the scope of this report.
5.5 The STRUCTO-CRETE™ Structural Concrete Panels
must be manufactured by the United States Gypsum
Company, 309 Hallberg Street, Delavan, Wisconsin,
under a quality control program with inspections
conducted by ICC Evaluation Service, LLC.
6.0 EVIDENCE SUBMITTED
6.1 Data in accordance with the ICC-ES Acceptance
Criteria for Structural Cementitious Floor Sheathing
Panels (AC318), dated June 2009 (editorially revised
August 2012).
6.2 Data in accordance with the ICC-ES Acceptance
Criteria for Horizontal Diaphragms Consisting of
Structural Cementitious Floor Sheathing Panels
Attached to Cold-formed Steel Framing (AC319),
dated June 2005 (editorially revised January 2012).
7.0 IDENTIFICATION
Each panel is labeled with the STRUCTO-CRETE™
Structural Concrete Panels brand name; the United States
Gypsum Company name and address; the inspection
agency name ICC-ES; the panel thickness; the maximum
joist spacing for the panel (referred to as maximum span);
the maximum allowable load (live and dead gravity load);
the ICC-ES report number (ESR-1792); the United States
Gypsum Company plant code; and the date of
manufacture.
5.1 The product must be installed in accordance with this
report, the manufacturer’s published instructions and
the applicable code. In the event of a conflict between
the manufacturer’s published installation instructions
and this report, this report governs.
TABLE 1—ALLOWABLE UNIFORM GRAVITY LOADS FOR
STRUCTO-CRETE™ STRUCTURAL CONCRETE PANELS
DEFLECTION LIMIT
ALLOWABLE UNIFORM LOAD (psf)
1
Joist Spacing (inches)
16
20
24
L/240
245
170
110
L/360
245
170
110
L/480
245
170
110
L/540
245
170
110
2
For SI: 1 inch = 25.4 mm, 1 psf =47.88 Pa.
1
These loads represent the load-carrying capacity of the panels spanning between the floor joists. A minimum of two spans is required. This
table does not consider the influence of joist deflection.
2
Load capacity limited by panel deflection. All other values limited by panel strength.
ESR-1792 | Most Widely Accepted and Trusted
Page 4 of 7
TABLE 2—SIMPLE BEAM UNBLOCKED DIAPHRAGM DESIGN LOADS FOR
STRUCTO-CRETE™ STRUCTURAL CONCRETE PANELS
1
JOIST SPACING
(inches)
2
FASTENER SPACING (inches)
3
SCREW PATTERN
SHEAR STRENGTH,
4
Su
(plf)
Perimeter
Field
24
4
12
A
1,349
24
6
12
A
1,178
24
4
12
B
1,341
24
6
12
B
1,053
16
4
12
B
1,462
16
6
12
B
1,178
For SI: 1 inch = 25.4 mm, 1 plf = 0.01459 N/mm, 1 ksi = 6.89 MPa.
1
5
Joists must have a minimum base-metal thickness of 54 mils (0.0538 inch), a minimum flange width of 1 /8 inches and a minimum specified
yield strength of 50 ksi.
2
5
Fasteners must be No. 8-18 size with a 1 /8-inch minimum length.
3
Screw Pattern A: Floor sheathing must be fastened with screws spaced at a maximum of 4 or 6 inches on center at the perimeter of the
diaphragm and at the panel-to-panel butt joints. At the panel corners, fasteners must be inset 2 inches. In the field of the panel, fasteners must
1
be spaced at a maximum of 12 inches on center. Fastener edge distance at all panel edges must be a minimum of /2 inch, except at tongueand-groove panel joints where the framing joists are perpendicular to the joint. At the tongue-and-groove panel joints where the framing joists
are perpendicular to the joint, two panel edge fasteners are required: one fastener placed 1 inch and another fastener 2 inches from the panel
edge. Figure 1 illustrates the Screw Pattern A fastener layout.
Screw Pattern B: Floor sheathing must be fastened with screws spaced at a maximum of 4 or 6 inches on center at the perimeter of the
diaphragm and at the panel-to-panel butt joints. At the panel corners, fasteners must be inset 2 inches. In the field of the panel, fasteners must
1
be spaced at a maximum of 12 inches on center. Fastener edge distance at all panel edges must be a minimum of /2 inch, except at tongueand-groove panel joints where the framing joists are perpendicular to the joint. At the tongue-and-groove panel joints where the framing joists
are perpendicular to the joint, one fastener must be placed 1 inch from the panel edge. Figure 2 illustrates the Screw Pattern B fastener layout.
4
The maximum ASD load must be determined by applying a minimum factor of safety of 2.5 to the tabulated nominal load for seismic forces,
and 2.35 for wind forces. The maximum LRFD load must be determined using a maximum resistance factor of 0.65 applied to the tabulated
nominal load for seismic forces and 0.70 for wind forces.
ESR-1792 | Most Widely Accepted and Trusted
Page 5 of 7
TABLE 3—DEFLECTION EQUATION FOR SIMPLE SPAN BEAM UNBLOCKED SHEAR DIAPHRAGMS
OF STRUCTO-CRETE™ STRUCTURAL CONCRETE PANELS ATTACHED
TO COLD-FORMED STEEL FRAMING
DEFLECTION EQUATION WITH A FASTENER SPACING OF 4 INCHES AT THE PANEL EDGES
AND 12 INCHES IN THE FIELD OF THE PANEL
3
∆4/12 = 5VL /8EAb + VL/4Gt + 0.010Len
3
For SI: ∆4/12 = 0.052VL /8EAb + VL/4Gt + Len/704
DEFLECTION EQUATION WITH A FASTENER SPACING OF 6 INCHES AT THE PANEL EDGES
AND 12 INCHES IN THE FIELD OF THE PANEL
3
∆6/12 = 5VL /8EAb + VL/4Gt + 0.030Len
3
For SI: ∆6/12 = 0.052VL /8EAb + VL/4Gt + Len/741
Description of Terms in Equation:
Term
Property Description
Units
V
Unit shear in the direction under consideration
L
Diaphragm length
feet
plf
b
Diaphragm width
feet
E
Elastic modulus of steel rim chords
A
Net area of steel rim chord cross section
29,500,000 psi
G
Shear modulus of sheathing for shear
T
Effective thickness of sheathing for shear
en
Screw-joint slippage at load per screw on perimeter of interior panel
en = 0.011 inch at 0.20Su
en = 0.019 inch at 0.33Su
en = 0.032 inch at 0.60Su
en = 0.084 inch at Su
Other values of en are permitted to be determined by interpolation
in.
∆
Maximum diaphragm deflection
in.
in
2
285,714 psi
0.75 in.
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 psi = 0.00689 MPa, 1 plf = 0.0146 N/mm.
1
en is dependent on V and must be selected based on the values in this table and the ratio of V/Su. Su is tabulated in Table 2.
TABLE 4—UNBLOCKED CANTILEVER DIAPHRAGM DESIGN LOADS FOR STRUCTO-CRETE™ STRUCTURAL CONCRETE PANELS
JOIST
SPACING
(inches)
JOIST GAGE NO.
24
24
1
2
FASTENER SPACING (inches)
Perimeter
Field
SCREW
3
PATTERN
SHEAR STRENGTH,
4
Su
(plf)
16
4
12
A
713
16
6
12
A
525
24
16
8
12
A
465
24
16
6
12
B
522
24
16
8
12
B
487
16
16
4
12
A
975
16
16
6
12
A
915
16
16
8
12
A
860
12
16
4
12
A
1121
12
16
6
12
A
940
12
16
8
12
A
772
24
18
4
12
A
449
24
18
6
12
A
458
24
18
8
12
A
468
For SI: 1 inch = 25.4 mm, 1 plf = 0.01459 N/mm, 1 ksi = 6.89 MPa.
1
Joists must have a minimum designated thickness of 54 mils (0.0538 inch) for No. 16 gage or 43 mils (0.043 inch) for No. 18 gage, a
5
minimum flange width of 1 /8 inches and a minimum specified yield strength of 50 ksi.
5
2Fasteners must be No. 8-18 size with a 1 /8-inch minimum length.
3Screw Pattern A: Floor sheathing must be fastened with screws spaced at a maximum of 4 or 6 inches on center at the perimeter of the
diaphragm and at the panel-to-panel butt joints. At the panel corners, fasteners must be inset 2 inches. In the field of the panel, fasteners must
1
be spaced at a maximum of 12 inches on center. Fastener edge distance at all panel edges must be a minimum of /2 inch, except at tongueand-groove panel joints where the framing joists are perpendicular to the joint. At the tongue-and-groove panel joints where the framing joists
are perpendicular to the joint, two panel edge fasteners are required: one fastener placed 1 inch and another fastener 2 inches from the panel
edge. Figure 1 illustrates the Screw Pattern A fastener layout.
Screw Pattern B: Floor sheathing must be fastened with screws spaced at a maximum of 4 or 6 inches on center at the perimeter of the
diaphragm and at the panel-to-panel butt joints. At the panel corners, fasteners must be inset 2 inches. In the field of the panel, fasteners must
1
be spaced at a maximum of 12 inches on center. Fastener edge distance at all panel edges must be a minimum of /2 inch, except at tongueand-groove panel joints where the framing joists are perpendicular to the joint. At the tongue-and-groove panel joints where the framing joists
are perpendicular to the joint, one fastener must be placed 1 inch from the panel edge. Figure 2 illustrates the Screw Pattern B fastener layout.
4The maximum ASD load must be determined using minimum safety factors of 2.5 for seismic forces and 2.35for wind forces. The maximum
LRFD load must be determined using maximum resistance factors of 0.65 for seismic forces and 0.70 for wind forces.
ESR-1792 | Most Widely Accepted and Trusted
Page 6 of 7
TABLE 5—DEFLECTION EQUATION FOR CANTILEVER UNBLOCKED SHEAR DIAPHRAGMS
OF STRUCTO-CRETE™ STRUCTURAL CONCRETE PANELS
ATTACHED TO COLD-FORMED STEEL FRAMING SPACED 24 INCHES ON CENTER
DEFLECTION EQUATION WITH A FASTENER SPACING OF 4 INCHES AT THE PANEL EDGES
AND 12 INCHES IN THE FIELD OF THE PANEL
3
∆4/12 = 5V(2L) /8EAb + V(2L)/4Gt + 0.486(2Len)
3
For SI: ∆4/12 = 0.052V(2L) /EAb + V(2L)/4Gt + 2Len /404
DEFLECTION EQUATION WITH A FASTENER SPACING OF 6 INCHES AT THE PANEL EDGIES
AND 12 INCHES IN THE FIELD OF THE PANDL
3
∆6/12 = 5V(2L) /8EAb + V(2L)/Gt + 0.446(2Len)
3
For SI: ∆6/12 = 0.052V(2L) /EAb + V(2L)/4Gt + 2Len/497
Description of Terms in Equation:
Term
Property Description
V
Unit shear in the direction under consideration
L
Diaphragm length
b
Diaphragm width
E
Elastic modulus of steel rim chords
A
Net area of steel rim chord cross section
G
Shear modulus of sheathing for shear
t
Effective thickness of sheathing for shear
Units
plf
feet
feet
29,500,000 psi
in
2
285,714 psi
0.75 in.
en
Screw-joint slippage at load per screw on perimeter of interior panel1
en = 0.011 inch at 0.20Su
en = 0.019 inch at 0.33Su
en = 0.032 inch at 0.60Su
en = 0.084 inch at Su
Other values of en are permitted to be determined by interpolation
in.
∆
Maximum diaphragm deflection
in.
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 psi = 0.00689 MPa, 1 plf = 0.0146 N/mm.
1
en is dependent on V and must be selected based on the values in this table and the ratio of V/Su. Su is tabulated in Table 4.
TABLE 6—DEFLECTION EQUATION FOR CANTILEVER UNBLOCKED SHEAR DIAPHRAGMS
OF STRUCTO-CRETE™ STRUCTURAL CONCRETE PANELS ATTACHED
TO COLD-FORMED STEEL FRAMING SPACED 16 INCHES ON CENTER
DEFLECTION EQUATION WITH A FASTENER SPACING OF 4 INCHES AT THE PANEL EDGES
AND 12 INCHES IN THE FIELD OF THE PANEL
3
∆4/12 = 5V(2L) /8EAb + V(2L)/4Gt + 0.494(2Len)
3
For SI: ∆4/12 = 0.052V(2L) /EAb + V(2L)/4Gt + 2Len/337
DEFLECTION EQUATION WITH A FASTENER SPACING OF 6 INCHES AT THE PANEL EDGES
AND 12 INCHES IN THE FIELD OF THE PANEL
3
∆6/12 = 5V(2L) /8EAb + V(2L)/Gt + 0.453(2Len)
3
For SI: ∆6/12 = 0.052V(2L) /EAb + V(2L)/4Gt + 2Len/393
Description of Terms in Equation:
Term
Property Description
V
Unit shear in the direction under consideration
L
Diaphragm length
plf
feet
b
Diaphragm width
E
Elastic modulus of steel rim chords
29,500,000 psi
A
Net area of rim chord cross section
in
G
Shear modulus of sheathing for shear
t
Effective thickness of sheathing for shear
feet
2
285,714 psi
0.75 in.
en
Screw-joint slippage at load per screw on perimeter of interior panel1
en = 0.011 inch at 0.20Su
en = 0.019 inch at 0.33Su
en = 0.032 inch at 0.60Su
en = 0.084 inch at Su
Other values of en are permitted to be determined by interpolation
in.
∆
Maximum diaphragm deflection
in.
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 psi = 0.00689 MPa, 1 plf = 0.0146 N/mm.
1
Units
en is dependent on V and must be selected based on the values in this table and the ratio of V/Su. Su is tabulated in Table 4.
ESR-1792 | Most Widely Accepted and Trusted
Page 7 of 7
FIGURE 1
FIGURE 2