CAPITULO IV REMATE DE BIENES
4.10 ENAJENACION FUERA DE REMATE
The provisions in Section B1 shall be used in conjunction with the requirements in Sections B2 through B5, as applicable.
B1.1 Loads and Load Combinations
Buildings or other structures and all parts therein shall be designed in accordance with the applicable building code to support all loads that are expected during its life. In the absence of an applicable building code, the loads, forces, and combinations of loads shall be in accordance with accepted engineering practice for the location under consideration as specified by the applicable sections of ASCE 7, Minimum Design Loads for Buildings and Other Structures in the United States and Mexico, or the National Building Code of Canada in Canada.
B1.1.1 Application of Live Load Reduction on Wall Studs
For the purpose of calculating the design axial load on a wall using floor live load reduction requirements in accordance with the applicable building code, the tributary area of the wall shall be limited to the floor area assigned to the individual wall framing members.
B1.1.2 Application of Wind Loads on Wall Studs in the United States and Mexico
In the United States and Mexico, the design of the wall studs shall be based on the following design wind loads:
(a) Combined bending and axial load effect based on Main Wind Force-Resisting System (MWFRS) wind loads.
(b) Bending load effect based on Components and Cladding (C&C) wind loads.
(c) Deflection limits based on 42% of Components and Cladding (C&C) wind loads with no axial loads.
B1.2 Design Basis
The proportioning, designing and detailing of cold-formed steel light-frame lateral force-resisting systems, trusses, structural members, connections and connectors shall be in accordance with AISI S100 [CSA S136], and the reference documents except as modified or supplemented by the requirements of this Standard.
B1.2.1 Floor Joists, Ceiling Joists and Roof Rafters
B1.2.1.1 Floor joists, ceiling joists and roof rafters shall be designed either on the basis of discretely braced design or on the basis of continuously braced design, in accordance with the following:
(a) Discretely Braced Design. Floor and roof assemblies using discretely braced design shall be designed neglecting the structural bracing and composite-action contribution of attached sheathing or deck. Discretely braced design shall include assemblies where the sheathing or deck is not attached directly to structural members.
(b) Continuously Braced Design. Unless noted otherwise in Section B2 or B4, the continuously braced design requirements of this Standard shall be limited to
floor joists, ceiling joists and roof rafters that comply with all of the following conditions:
(1) Maximum web depth = 14 inches (356 mm)
(2) Maximum design thickness = 0.1242 inches (3.155 mm) (3) Minimum design yield strength, Fy = 33 ksi (230 MPa) (4) Maximum design yield strength, Fy = 50 ksi (345 MPa)
B1.2.1.2 Where continuously braced design is used, the construction documents shall identify the sheathing or deck as a structural element.
B1.2.1.3 A web with one or more holes shall be designed in accordance with AISI S100 [CSA S136], or reinforced in accordance with an approved design or as specified by a registered design professional.
B1.2.2 Wall Studs
B1.2.2.1 Wall studs shall be designed either on the basis of all steel design or on the basis of sheathing braced design, in accordance with the following:
(a) All Steel Design. Wall stud assemblies using all steel design shall be designed neglecting the structural bracing and composite-action contribution of the attached sheathings.
(b) Sheathing Braced Design. Wall stud assemblies using sheathing braced design shall have sheathing attached to both flanges of the wall stud or sheathing attached to the one flange and discrete bracing to the other flange. The stud shall be connected to the bottom and top track or other horizontal member(s) of the wall to provide lateral and torsional support to the wall stud in the plane of the wall. Wall studs with sheathing attached to both sides that is not identical shall be designed based on the assumption that the weaker of the two sheathings is attached to both sides.
B1.2.2.2 When sheathing braced design is used, the construction documents shall identify the sheathing as a structural element.
B1.2.2.3 For curtain wall studs, the combination of sheathing attached to one side of the wall stud and discrete bracing for the other flange is permitted. The spacing of discrete bracing shall be no greater than 8 ft (2.44 m) on center. For design, the nominal flexural strength [resistance] shall be determined by AISI S100 Section C3.1.
When the compression flange has sheathing attached, AISI S100 Section C3.1.1 is permitted. When the compression flange does not have sheathing attached, AISI S100 Section C3.1.2 shall apply. In both cases, AISI S100 Section C3.1.4 for distortional buckling shall also be considered.
B1.2.2.4 In the United States and Mexico, when sheathing braced design is used, the wall studs shall also be evaluated without the sheathing bracing for the following load combination:
B1.2.2.5 In Canada, the provisions for sheathing braced design shall be in accordance
with a theory, tests, or rational engineering analysis and shall comply with Chapter C of AISI S100 [CSA S136], as applicable.
B1.2.2.6 A web with one or more holes shall be designed in accordance with AISI S100 [CSA S136].
B1.2.3 In-Line Framing
B1.2.3.1 Each joist, rafter, truss, and structural wall stud (above or below) shall be aligned vertically in accordance with the limits depicted in Figure B1.2.3-1.
B1.2.3.2 The alignment tolerance shall not be required to be met when a structural load distribution member is specified in accordance with the approved construction documents.
Figure B1.2.3-1 In-Line Framing B1.2.4 Sheathing Span Capacity
B1.2.4.1 Floor joist and floor truss spacing shall be limited by the span capacity of the floor structural sheathing material.
B1.2.4.2 Wall stud spacing shall be limited by the span capacity of the wall structural sheathing material.
B1.2.4.3 The spacing of roof and ceiling framing members shall be limited by the span capacity of the ceiling or roof structural sheathing material.
B1.2.5 Load Path
A continuous load path to the foundation shall be provided for the uplift, shear, and
compression forces due to lateral wind forces, seismic forces, or other predominantly horizontal forces, or combinations thereof, imposed upon the structure in accordance with the applicable building code. Elements resisting forces contributed by multiple stories shall be designed for the sum of forces contributed by each story in conformance to applicable building code.
B1.2.6 Principles of Mechanics
Where cold-formed steel structural members and connections are not required to be designed in accordance with the additional provisions of Section A1.3, the provisions of this section are permitted for lateral force-resisting systems.
B1.2.6.1 The shear resistance of shear walls, strap braced walls and diaphragms is permitted to be determined by principles of mechanics using values of fastener strength, sheathing shear resistance, and strap strength, as applicable.
B1.2.6.2 When determined by the principles of mechanics, the nominal strength [nominal resistance] defines the maximum resistance that the diaphragm, shear wall, or strap braced wall is capable of developing.
B1.2.6.3 Required strength [effect of factored loads] shall be determined in accordance with the force requirements in the applicable building code.
B1.2.6.4 When determined by the principles of mechanics, values for systems defined in this Standard shall be scaled to the values in this Standard.
B1.3 Built-Up Section Design
Built-up sections shall be evaluated in accordance with Section D1 of AISI S100 [CSA S136] and the additional requirements of Sections B1.3.1 and B1.3.2, as applicable.
B1.3.1 For either all steel design or sheathing braced design, the available strength [factored resistance] of built-up sections shall be determined in accordance with Section D1.2 of AISI S100 [CSA S136].
Exception: Where a built-up axial load bearing section comprised of two studs oriented back-to-back forming an I-shaped cross-section is seated in a track in accordance with the requirements of Section C3.4.3 and the top and bottom end bearing detail of the studs consists of support by steel or concrete components with adequate strength and stiffness to preclude relative end slip of the two built-up stud sections, the compliance with the end connection provisions of AISI S100 Section D1.2(b) is not required.
B1.3.2 When the connection requirements of Section D1.2 of AISI S100 [CSA S136] or the exception permitted in B1.3.1 are not met, the available strength [factored resistance] of built-up sections shall be equal to the sum of the available strengths [factored resistances]
of the individual members of the built-up cross-section.
B1.4 Properties of Sections
The properties of sections shall be full cross-section properties, except where use of a reduced cross-section or effective design width is required by AISI S100 [CSA S136].
B1.5 Connection Design
Connections using screws, welds, bolts, or power-actuated fasteners shall be designed in accordance with AISI S100 [CSA S136] and the additional requirements of this Standard. For connections using other fastener types, design values [factored resistances] shall be determined
by testing in accordance with Section F1 of AISI S100 [CSA S136].
B1.5.1 Screw Connections
B1.5.1.1 Steel-to-Steel Screws
Screw fasteners for steel-to-steel connections shall be in compliance with ASTM C1513 or the approved construction documents.
B1.5.1.2 Sheathing Screws
Screw fasteners for structural sheathing to steel connections shall be in compliance with ASTM C1513 or the approved construction documents.
B1.5.1.3 Spacing and Edge Distance
B1.5.1.3.1 For screw fasteners in steel-to-steel connections to be considered fully effective, the minimum edge distance shall be 3 times the nominal diameter.
Exception: Where the edge is parallel to the direction of the applied force, the minimum edge distance of screw fasteners shall be 1.5 times the nominal diameter.
B1.5.1.3.2 For screw fasteners in steel-to-steel connections to be considered fully effective, the minimum center-to-center spacing shall be 3 times the nominal diameter.
Exception: Where the center-to-center spacing of screw fasteners in steel-to-steel connections is less than 3 times the nominal diameter but greater than or equal to 2 times the nominal diameter, screw fasteners shall be considered 80 percent effective.
B1.5.1.4 Gypsum Board
Screw fasteners for gypsum board to steel connections shall be bugle head style in compliance with ASTM C954, ASTM C1002, or ASTM C1513, as applicable.
B1.5.2 Welded Connections
Welded connections shall be in accordance with AISI S100 [CSA S136] and AWS D1.3.
The design capacity of welds shall be in accordance with AISI S100 [CSA S136].
B1.5.3 Bolts
Bolted cold-formed steel connections shall be designed and installed in accordance with AISI S100 [CSA S136].
B1.5.4 Power-Actuated Fasteners
Cold-formed steel connections using power-actuated fasteners shall be designed and installed in accordance with AISI S100 [CSA S136].
B1.5.5 Other Connectors
Other types of connections (e.g., rivet fasteners and clinch joining) shall be designed, fabricated and installed in accordance with the design requirements as set forth by the approved construction documents and the fastener manufacturer’s requirements.
B1.5.6 Connection to Other Materials
Bolts, nails, anchor bolts or other fasteners used to connect cold-formed steel framing to wood, masonry, concrete or other steel components shall be designed and installed in accordance with the applicable building code or the approved construction documents.
B2 Floor and Ceiling Framing
The requirements in Section B2 shall be used in conjunction with the requirements in Section B1, as applicable.
B2.1 Scope
Sections B2.2 through B2.7 are applicable to floor and ceiling systems that utilize cold-formed steel structural members.
B2.2 Floor Joist Design
Floor joists shall be designed in accordance with the requirements of this section.
B2.2.1 Bending
The available bending strength [factored resistance] of floor joists shall be the lesser of the strengths determined in accordance with Sections B2.2.1.1 and B2.2.1.2.
B2.2.1.1 Lateral-Torsional Buckling
Floor joists shall be designed either on the basis of discretely braced design or on the basis of continuously braced design, in accordance with the following:
(a) Discretely Braced Design. For discretely braced design, flexure shall be evaluated in accordance with Section C3.1.2 of AISI S100 [CSA S136].
(b) Continuously Braced Design. For continuously braced design, where structural sheathing or steel deck is attached to the compression flange of the floor joist in accordance with Section B2.6(1) and the tension flange is braced in accordance with Section B2.6(2), flexure shall be evaluated in accordance with Section C3.1.1 of AISI S100 [CSA S136].
B2.2.1.2 Distortional Buckling
Floor joists shall be designed either on the basis of discretely braced design or on the basis of continuously braced design, in accordance with the following:
(a) Discretely Braced Design. For discretely braced design, flexure shall be evaluated in accordance with Section C3.1.4 of AISI S100 [CSA S136]. If the discrete bracing restricts rotation of the compression flange about the web/flange juncture, the distance between braces shall be used as Lm when applying AISI S100 [CSA S136].
(b) Continuously Braced Design. For continuously braced design, flexure shall be evaluated in accordance with Section C3.1.4 of AISI S100 [CSA S136]. The rotational stiffness, kφ, provided by the sheathing or deck to the floor joist shall be determined in accordance with Appendix 1.
B2.2.2 Shear
Shear shall be evaluated in accordance with Section C3.2 of AISI S100 [CSA S136].
B2.2.3 Web Crippling
Web crippling shall be evaluated in accordance with Section C3.4 of AISI S100 [CSA S136], unless a bearing stiffener is used in accordance with the requirements of Section B2.5.1.
B2.2.4 Bending and Shear
The combination of flexure and shear shall be evaluated in accordance with Section C3.3 of AISI S100 [CSA S136].
B2.2.5 Bending and Web Crippling
The combination of flexure and web crippling shall be evaluated in accordance with Section C3.5 of AISI S100 [CSA S136], unless a bearing stiffener is used in accordance with the requirements of Section B2.5.1.
B2.3 Ceiling Joist Design
Ceiling joists shall be designed in accordance with the requirements of this section.
B2.3.1 Tension
Tension shall be evaluated in accordance with Section C2 of AISI S100 [CSA S136].
B2.3.2 Compression
The available compression strength [factored resistance] of ceiling joists shall be the lesser of the strengths determined in accordance with Sections B2.3.2.1 and B2.3.2.2.
B2.3.2.1 Yielding, Flexural, Flexural-Torsional and Torsional Buckling
Compression shall be evaluated in accordance with Section C4.1 of AISI S100 [CSA S136].
B2.3.2.2 Distortional Buckling
Ceiling joists shall be designed either on the basis of discretely braced design or on the basis of continuously braced design, in accordance with the following:
(a) Discretely Braced Design. For discretely braced design, compression shall be evaluated in accordance with Section C4.2 of AISI S100 [CSA S136]. If the discrete bracing restricts rotation of the compression flange about the web/flange juncture, the distance between braces shall be used as Lm when applying AISI S100 [CSA S136].
(b) Continuously Braced Design. For continuously braced design, compression alone shall be evaluated in accordance with Section C4.2 of AISI S100 [CSA S136]. The rotational stiffness, kφ, provided by the sheathing or deck to the ceiling joist shall be determined in accordance with Appendix 1.
B2.3.3 Bending
The available flexural strength [resistance] of ceiling joists shall be the lesser of the strengths determined in accordance with Sections B2.3.3.1 and B2.3.3.2.
B2.3.3.1 Lateral-Torsional Buckling
Ceiling joists shall be designed either on the basis of discretely braced design or on
the basis of continuously braced design, in accordance with the following:
(a) Discretely Braced Design. For discretely braced design, flexure shall be evaluated in accordance with Section C3.1.2 of AISI S100 [CSA S136].
(b) Continuously Braced Design. For continuously braced design, where structural sheathing or steel deck is attached to the compression flange of the ceiling joist in accordance with Section B2.6 (1) and the tension flange is braced in accordance with Section B2.6(2), flexure for gravity loading shall be evaluated in accordance with Section C3.1.1 of AISI S100 [CSA S136] and flexure for uplift loading shall be evaluated in accordance with Sections C3.1.2 and D6.1.1 of AISI S100 [CSA S136].
B2.3.3.2 Distortional Buckling
Ceiling joists shall be designed either on the basis of discretely braced design or on the basis of continuously braced design, in accordance with the following:
(a) Discretely Braced Design. For discretely braced design, flexure shall be evaluated in accordance with Section C3.1.4 of AISI S100 [CSA S136]. If the discrete bracing restricts rotation of the compression flange about the web/flange juncture, the distance between braces shall be used as Lm when applying AISI S100 [CSA S136].
(b) Continuously Braced Design. For continuously braced design, flexure shall be evaluated in accordance with Section C3.1.4 of AISI S100 [CSA S136]. The rotational stiffness, kφ, provided by the sheathing or deck to the ceiling joist shall be determined in accordance with Appendix 1.
B2.3.4 Shear
Shear shall be evaluated in accordance with Section C3.2 of AISI S100 [CSA S136].
B2.3.5 Web Crippling
Web crippling shall be evaluated in accordance with Section C3.4 of AISI S100 [CSA S136], unless a bearing stiffener is used in accordance with the requirements of Section B2.5.1.
B2.3.6 Axial Load and Bending
The combination of axial load and bending shall be evaluated in accordance with Section C5 of AISI S100 [CSA S136].
B2.3.7 Bending and Shear
The combination of flexure and shear shall be evaluated in accordance with Section C3.3 of AISI S100 [CSA S136].
B2.3.8 Bending and Web Crippling
The combination of flexure and web crippling shall be evaluated in accordance with Section C3.5 of AISI S100 [CSA S136], unless a bearing stiffener is used in accordance with the requirements of Section B2.5.1.
B2.4 Floor Truss Design
Floor trusses shall be designed in accordance with Chapter E.
B2.5 Bearing Stiffeners
Bearing stiffeners, other than clip angle bearing stiffeners, shall be designed in accordance with Section C3.7 of AISI S100 [CSA S136]. Clip angle bearing stiffeners, as permitted in Section B2.2.3, shall be designed in accordance with Section B2.5.1.
B2.5.1 Clip Angle Bearing Stiffeners
The nominal web crippling strength [resistance] of a floor joist connected to a rim track using a clip angle bearing stiffener shall be determined in accordance with the following:
Pn = 0.9 (Pj + Pt + 0.5AgFy) (Eq. B2.5.1-1)
where
Pj = Nominal end two-flange web crippling strength [resistance] of the floor joist determined in accordance with Section C3.4.1 of AISI S100 [CSA S136]
Pt = Nominal interior two-flange web crippling strength [resistance] of the rim track determined in accordance with Section C3.4.1 of AISI S100 [CSA S136]
Ag = Gross area of the clip angle bearing stiffener Fy = Yield strength of clip angle
The available strength [factored resistance] shall be determined using the safety factor (Ω) or the resistance factor (φ) as follows:
Ωc = 1.80 for ASD φ c = 0.85 for LRFD φ c = 0.70 for LSD
Equation B2.5.1-1 shall be valid for the range of parameters listed in Table B2.5.1-1, as illustrated in Figure B2.5-1.
Figure B2.5-1 Fastening of Clip Angle Bearing Stiffener 1” (25.4 mm)
(maximum) 1” (25.4 mm)
(maximum) Depth of
Bearing Stiffener
Width of Bearing Stiffener
Three (3) Equally Spaced Screws
Table B2.5.1-1
Parameters for Equation B2.5.1-1
Parameter Minimum Maximum
Floor Joist and Rim Track:
Design Thickness 0.0451” (1.146 mm) 0.1017” (2.583 mm)
No. 8 for angle design thickness less than or equal to 0.0566”
(1.438 mm), and No. 10 for thicker angles
n/a
Fasteners
3 screws connecting legs of bearing stiffener to joist and rim track web, in accordance with Figure B2.5-1
n/a
B2.6 Bracing Design
Bracing members shall be designed either on the basis of discretely braced design or on the basis of continuously braced design, in accordance with the following:
(a) Discretely Braced Design. For discretely braced design, bracing members shall be designed in accordance with Section D3 of AISI S100 [CSA S136].
(b) Continuously Braced Design. For continuously braced design, bracing members shall be designed in accordance with Section D3 of AISI S100 [CSA S136], unless the following requirements, as applicable, are met:
(1) The sheathing or deck shall consist of a minimum of 3/8 inch (9.5 mm) wood structural sheathing that complies with DOC PS 1, DOC PS 2, CSA O437 or CSA O325, or steel deck with a minimum profile depth of 9/16 in. (14.3 mm) and a minimum thickness of 0.0269 in. (0.683 mm). The sheathing or deck shall be attached with minimum No. 8 screws at a maximum 12 inches (305 mm) on center.
(2) Floor joists and ceiling joists with simple or continuous spans that exceed 8 feet (2.44 m) shall have the tension flanges laterally braced. Each intermediate brace shall be spaced at 8 feet (2.44 m) maximum and shall be designed to resist a required lateral force, PL, determined in accordance with the following:
For uniform loads:
PL = 1.5(m/d) F (Eq. B2.6-1)
where
m = Distance from shear center to mid-plane of web
d = Depth of C-shape section F = wa
w = Uniform design load [factored load]
a = Distance between center line of braces For concentrated loads:
If x ≤ 0.3a:
PL = 1.0(m/d) F (Eq. B2.6-2)
If 0.3a < x < 1.0a:
PL = 1.4(m/d)(1-x/a) F (Eq. B2.6-3)
where
m = Distance from shear center to mid-plane of web d = Depth of C-shape section
F = Concentrated design load [factored load]
x = Distance from concentrated load to brace a = Distance between center line of braces B2.7 Floor Diaphragm Design
Diaphragms shall be designed in accordance with Section B5.
B3 Wall Framing
The requirements in Section B3 shall be used in conjunction with the requirements in Section B1, as applicable.
B3.1 Scope
Sections B3.2 through B3.5 are applicable to wall systems that utilize cold-formed steel
Sections B3.2 through B3.5 are applicable to wall systems that utilize cold-formed steel