SANS 517 Mr Venish Dewrajh

ISBN 978-0-626-27369-9
SANS 517:2013
Edition 1.2
SOUTH AFRICAN NATIONAL STANDARD
Light steel frame building
Published by SABS Standards Division
1 Dr Lategan Road Groenkloof Private Bag X191 Pretoria 0001
Tel: +27 12 428 7911 Fax: +27 12 344 1568
www.sabs.co.za
© SABS
Licensed exclusively to Venish Dewrajh.
Copying and network storage prohibited.

SANS 517:2013
Edition 1.2
Table of changes
Change No. Date Scope
Amdt 1 2011 Amended to correct the name of a council, to update referenced
standards, to correct a cross-reference, to correct a dimension in
figure 12, to modify the dimension for the thickness of galvanized
sheets, to correct figure 26, to modify the R-value for category 1
buildings (see table 14), to delete the fire rating requirement, and to
insert a title for figure 45(a).
Amdt 2 2013 Amended to update referenced standards, to correct the map on
geographic regions related to wind speeds, to update requirements
in the tables on external pressure coefficient cpe for mono-pitched
roofs and duo-pitched roofs, to update requirements for wall
elements, and to correct the map on climate zones in South Africa.
Foreword
This South African standard was approved by National Committee SABS TC 98, Structural and
geotechnical design standards, in accordance with procedures of the SABS Standards Division, in
compliance with annex 3 of the WTO/TBT agreement.
This document was published in July 2013.
This document supersedes SANS 517:2011 (edition 1.1).
A vertical line in the margin shows where the text has been technically modified by amendment
No. 2.
Reference is made in 4.1 and 6.1 to the "relevant national legislation". In South Africa, this means
the National Building Regulations and Building Standards Act, 1977 (Act No. 103 of 1977).
Reference is made in 5.12.2 to the "relevant national legislation". In South Africa, this means the
Occupational Health and Safety Act, 1993 (Act No. 85 of 1993).
Reference is made in 8.2.1 to the "relevant national body". In South Africa, this means the
Engineering Council of South Africa (ECSA), or the South African Council for Natural Scientific
Professions (SACNASP). Amdt 1
Annexes A, B and C are for information only.
Introduction
The Southern African Light Steel Frame Building Association (SASFA) was formed as a division of
the Southern African Institute of Steel Construction by a group of interested companies to
coordinate the systematic development of this new industry and to ensure quality throughout the
value chain. One of the major tasks identified was to establish this standard for light steel frame
building.

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Contents
Page
Foreword
Introduction
1 Scope .................................................................................................................................. 3
2 Normative references .......................................................................................................... 4
3 Definitions and symbols....................................................................................................... 6
3.1 Definitions ................................................................................................................... 6
3.2 Symbols ...................................................................................................................... 19
4 Materials .............................................................................................................................. 20
4.1 General ....................................................................................................................... 20
4.2 Steel . .......................................................................................................................... 20
4.3 Fasteners ................................................................................................................... 20
4.4 Interior lining of walls and ceilings ............................................................................. 20
4.5 Exterior cladding of walls (excluding masonry) .......................................................... 21
4.6 Masonry for exterior cladding of walls and foundation walls ...................................... 21
4.7 Thermal and acoustic insulation ................................................................................ 21
4.8 Damp-proof courses ................................................................................................... 21
4.9 Wall ties and fixings ................................................................................................... 21
4.10 Sheathing to prevent racking ..................................................................................... 21
4.11 Vapour permeable membranes ................................................................................. 21
4.12 Reinforced concrete ................................................................................................... 22
4.13 Holding down devices ................................................................................................ 22
4.14 Floors ......................................................................................................................... 22
5 Steel structure ..................................................................................................................... 22
5.1 Basis for design .......................................................................................................... 22
5.2 Resistances of structural elements and connections ................................................. 23
5.3 Design actions ............................................................................................................ 23
5.4 Design criteria ............................................................................................................ 32
5.5 Methods of assessment of resistances ...................................................................... 33
5.6 Roof members ............................................................................................................ 33
5.7 Wall elements ............................................................................................................. 36
5.8 Floor members ........................................................................................................... 42
5.9 Connections ............................................................................................................... 45
5.10 Bracing ....................................................................................................................... 46
5.11 Testing ........................................................................................................................ 49
5.12 Construction of the steel frame .................................................................................. 50
5.13 Tolerances ................................................................................................................. 51
5.14 Durability and corrosion ............................................................................................. 55
5.15 Support of wall cupboards and fittings ....................................................................... 56
5.16 Earthing ...................................................................................................................... 57
6 Walls, roofs and suspended floors ...................................................................................... 57
6.1 Scope ......................................................................................................................... 57
6.2 General requirements ................................................................................................ 57
6.3 Exterior walls .............................................................................................................. 61
6.4 Internal walls ................................................................................................................. 68

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Page
6.5 Roofs and ceilings....................................................................................................... 71
6.6 Suspended floors ........................................................................................................ 76
7 Installation of services ......................................................................................................... 78
7.1 Positioning of services in concrete floor slabs ........................................................... 78
7.2 Holes in members ...................................................................................................... 78
7.3 Plumbing pipework and fittings ................................................................................... 79
7.4 Electrical cables and fittings ....................................................................................... 80
8 Foundations ........................................................................................................................ 80
8.1 General ....................................................................................................................... 80
8.2 Site investigation ........................................................................................................ 80
8.3 Selection of foundation type ....................................................................................... 83
8.4 Standard designs ....................................................................................................... 88
8.5 Design by engineering principles ............................................................................... 93
8.6 Site preparation and filling .......................................................................................... 95
8.7 Additional precautions ................................................................................................ 98
Annex A (informative) Guide for determination of self-weights ............................................ 101
Annex B (informative) System effect .................................................................................... 104
Annex C (informative) Classification of damage .................................................................. 106
Bibliography ........................................................................................................................... 109

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Light steel frame building
1 Scope
This standard establishes rules and requirements for the design, fabrication and construction of
buildings with light steel frames, clad and insulated with appropriate materials, including the walls,
roofs, floors, and foundations of such buildings.
This standard applies to buildings which do not exceed the geometric limitations given in figure 1.
This standard does not cover doors, windows, services, finishes or other elements of buildings that
are either not peculiar to light steel frame buildings or do not have a direct interface with the steel
frame.
Dimensions in metres
W = width
L = length
Figure 1 — Geometric limitations

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2 Normative references
2.1 Standards
The following referenced documents are relevant for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the
referenced document (including any amendments) applies. Information on currently valid national
and international standards can be obtained from the SABS Standards Division.
AS 2870, Residential slabs and footings – Construction. Amdt 1
ASTM D 7033, Standard practice for establishing design capacities for oriented strand board (OSB)
wood-based structural-use panels.
ASTM E 1677, Standard specification for air barrier (AB) material or system for low-rise framed
building walls.
ISO 11997-2, Paints and varnishes – Determination of resistance to cyclic corrosion conditions –
Part 2: Wet (salt fog)/dry/humidity/UV light.
SANS 204, Energy efficiency in buildings. Amdt 2
SANS 227, Burnt clay masonry units.
SANS 248, Bituminous damp-proof courses.
SANS 266, Gypsum plasterboard.
SANS 457-2, Wooden poles, droppers, guardrail posts and spacer blocks – Part 2: Softwood
species.
SANS 457-3 (SABS 457-3), Wooden poles, droppers, guardrail posts and spacer blocks – Part 3:
Hardwood species.
SANS 675, Zinc-coated fencing wire.
SANS 803, Fibre-cement boards.
SANS 952-1, Polymer film for damp-proofing and waterproofing in buildings – Part 1: Monofilament
and co-extruded products. Amdt 1
SANS 952-2, Polymer film for damp-proofing and waterproofing in buildings – Part 2: Laminated
(non-woven) products. Amdt 1
SANS 1200 DM (SABS 1200 DM), Standardized specification for civil engineering construction –
Section DM: Earthworks (roads, subgrade).
SANS 1200 M (SABS 1200 M), Standardized specification for civil engineering construction –
Section M: Roads (general).
SANS 1273, Fasteners for roof and wall coverings in the form of sheeting.
SANS 1381-1, Materials for thermal insulation of buildings – Part 1: Fibre thermal insulation mats.
SANS 1381-4, Materials for thermal insulation of buildings – Part 4: Reflective foil laminates (rolls,
sheets and sections).

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SANS 1381-6, Materials for thermal insulation of buildings – Part 6: Cellulose loose fill thermal
insulation material.
SANS 1383, Rigid urethane and isocyanurate foams for use in thermal insulation.
SANS 1700 (all parts), Fasteners.
SANS 3575/ISO 3575, Continuous hot-dip zinc-coated carbon steel sheet of commercial and
drawing qualities.
SANS 4998/ISO 4998, Continuous hot-dip zinc-coated carbon steel sheet of structural quality.
SANS 7253/ISO 7253, Paints and varnishes – Determination of resistance to neutral salt spray
(fog).
SANS 9364 /ISO 9364, Continuous hot-dip aluminium/zinc-coated steel sheet of commercial,
drawing and structural qualities.
SANS 10005, The preservative treatment of timber.
SANS 10043, The installation of wood and laminate flooring.
SANS 10100-1 (SABS 0100-1), The structural use of concrete – Part 1: Design.
SANS 10100-2 (SABS 0100-2), The structural use of concrete – Part 2: Materials and execution of
work.
SANS 10106, The installation, maintenance, repair and replacement of domestic solar water
heating systems.
SANS 10124, The application of soil insecticides for the protection of buildings.
SANS 10142-1, The wiring of premises – Part 1: Low-voltage installations.
SANS 10160 (all parts), Basis of structural design and actions for buildings and industrial structures.
Amdt 1
SANS 10161 (SABS 0161), The design of foundations for buildings. Amdt 2
SANS 10162-1, The structural use of steel – Part 1: Limit-states design of hot-rolled steelwork.
SANS 10162-2 (SABS 0162-2), The structural use of steel – Part 2: Cold- formed steel structures.
SANS 10177-2, Fire testing of materials, components and elements used in buildings – Part 2: Fire
resistance test for building elements.
SANS 10249, Masonry walling.
SANS 10252-1, Water supply and drainage for buildings – Part 1: Water supply installations for
buildings.
SANS 10252-2 (SABS 0252-2), Water supply and drainage for buildings – Part 2: Drainage
installations for buildings.
SANS 10254, The installation, maintenance, replacement and repair of fixed electric storage water
heating systems.

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SANS 10400-A, The application of the National Building Regulations – Part A: General principles
and requirements. Amdt 2
SANS 10400-B, The application of the National Building Regulations – Part B: Structural design.
Amdt 2
SANS 10400-P, The application of the National Building Regulations – Part P: Drainage. Amdt 2
SANS 10400-H, The application of the National Building Regulations – Part H: Foundations.
Amdt 2
TRH 14, Guidelines for road construction materials.
2.2 Other publications
National Home Builders Registration Council. Home building manual. Parts 1 to 3. Rev. 1. NHBRC,
1999.
Agrément South Africa, Booklet B1, Performance criteria and minimum requirements for the
assessment of innovative methods of construction.
3 Definitions and symbols
For the purposes of this document, the following definitions and symbols apply.
3.1 Definitions
3.1.1
acceptable
acceptable to the authority administering this standard, or to the parties concluding the purchase
contract, as relevant
3.1.2
acoustic insulation
insulation material installed to reduce the transmittance of sound from one side of the insulation to
the other
3.1.3
air infiltration
air movement through a material, component or an assembly into a building
3.1.4
balconies
external areas, at least one metre above ground level
3.1.5
beam
horizontal structural member that supports vertical loads and is subject to flexural stresses
3.1.6
bearer
subfloor beam supporting the floor joists (see figures 2 and 7)

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3.1.7
bottom wall plate
bottom plate
member running along the bottom of a wall frame and resting directly on a foundation wall,
foundation beam or floor slab (see figures 2 and 4)
3.1.8
bracing
diagonal members, or diaphragms, that resist lateral movement of members or racking forces (or
both) (see figures 2, 9 and 10)
3.1.9
brandering
member fixed to roof trusses or rafters to support the ceiling (see figure 3), and which does not
apply to suspended ceilings
3.1.10
brick veneer
single leaf non-load-bearing brick wall serving as exterior cladding
3.1.11
building envelope
exterior skin of a building, consisting of the floor, external walls, ceiling under roof overhangs, and
roof cladding
3.1.12
bulk insulation
mineral or synthetic fibre wool in rolls which are available in different densities and thicknesses
NOTE Referred to as 'bats' when cut to length.
3.1.13
category 1 building
building which
a) is designated as being a class A3, A4, F2, G1, H2, H3 and H4 occupancy (see SANS 10400-A),
Amdt 2
b) has no basements,
c) has a maximum length between intersecting walls or members providing lateral support of 6,0 m,
and
d) has a floor area not exceeding 80 m2
3.1.14
chord
top (rafter) or bottom member of a truss (see figures 2 and 3)
3.1.15
competent person
person who is qualified, by virtue of his education, training, experience and contextual knowledge,
to make a determination regarding the performance of a building or part thereof in relation to a
functional regulation

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3.1.16
crawl space
gap between a suspended ground floor and the underlying ground, to allow for inspection and
maintenance of structural members supporting the floor
3.1.17
domestic dwelling
building used for residential purposes, consisting of one or more dwelling units
3.1.18
energy efficiency
measure of the minimization of the need to use energy for heating and cooling of buildings
3.1.19
expansion joint
discontinuation between elements, such as wall panels, to allow for relative movement between
adjoining elements and to prevent stresses arising in the elements from such differential
movements
3.1.20
exterior wall
wall forming part of the building envelope, and which is normally load-bearing
3.1.21
external wall cladding
weather resistant external skin of a building, fixed to the light steel frame
NOTE External wall cladding may consist of a single leaf of brickwork (veneer), weather resistant boards or
reinforced plaster.
3.1.22
fibre cement board
composite material made of cement, sand and cellulose or synthetic fibres (or both)
3.1.23
fire rating
shortest period for which a building element or building component will comply with the
requirements for stability, integrity and insulation (see 4.1)
3.1.24
fire resistance
ability of a composite floor, wall or ceiling assembly to remain stable when exposed to heat
generated by fire
3.1.25
floor joist
beam that directly supports the flooring (see figures 2 and 7)
3.1.26
glass wool
material made from glass, spun into fibre-like structure
NOTE Available in different densities (kilogram per cubic metre) for use as insulation.

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3.1.27
gypsum board
board with a gypsum plaster core with an envelope of two layers of paper
NOTE Gypsum board can be specified to be fire resistant or water resistant.
3.1.28
insulation
building fabric installed in wall and roof cavities, or attached to steel framing elements or cladding
materials, to provide resistance against heat or sound transfer (or both), between rooms or
dwellings
NOTE The insulation specified for category 1 buildings does not comply with the insulation requirement of
SANS 204. It was included to allow for low cost buildings. Amdt 2
3.1.29
internal lining
cladding of an internal wall, the inner face of an external wall or a ceiling that provides a neat finish,
fire resistance to the light steel structure and part of the insulation
3.1.30
jack stud
vertical member in a wall frame below or above a window or door opening (see figure 2)
3.1.31
jamb stud
stud located beside an opening in a wall frame such as a window or door opening (see figures 2, 5
and 6)
3.1.32
light steel frame building
buildings in which the load-bearing structure, comprising the wall framing, columns, beams, trusses,
panels or any combination of these, consists of assemblies of thin-walled cold-formed steel sections
3.1.33
lintel
horizontal member in a wall frame spanning over an opening (see figures 2, 5 and 6)
3.1.34
nogging
horizontal restraining member fixed between studs in a wall frame (see figures 2 and 4)
3.1.35
non-load-bearing walls
wall that is not required to carry gravity or wind loads (see figure 8)
3.1.36
notching
localised removal of material from a steel element that involves cutting away a flange of the element
or a portion thereof
3.1.37
open web joist
parallel-chord truss that supports concentrated or distributed loads, such as floor joists, rafters in a
roof and lintels (see figures 5 and 6)

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3.1.38
purlin
member fixed to roof trusses or rafters to support roof sheeting (see figure 3)
3.1.39
racking
in-plane distortion of a framing module such as a wall or a roof, involving movement of the top
relative to the bottom, in the plane of the module
3.1.40
reflective insulation
material with a reflective surface such as a reflective foil laminate capable of reducing radiant heat
flow due to its high reflectivity and low emissivity
3.1.41
roof batten
member fixed to roof trusses or rafters to support roof tiles (see figure 3)
3.1.42
R-value
measure of resistance to heat flow of a material or composite element, including the effects of any
air spaces or reflective surfaces (or both)
NOTE The higher the R-value, the better the ability of the material or composite element to resist the flow of
heat through it. R-values are expressed using the units, m
2
·K/W.
3.1.43
sheathing
rigid board fastened directly to the wall studs to provide support for exterior cladding material, to
lend structural support to the light steel frame members or to enhance the insulation of exterior
walls
3.1.44
sheet insulation
insulation materials in (rigid) sheet form
NOTE Sheet insulation is available in different densities and thicknesses, with or without reflective surfaces.
3.1.45
sound insulation
measures taken to reduce the transfer of sound through a composite wall or floor assembly
(see 3.1.2)
3.1.46
spacing
unless otherwise specified, the centre-to-centre distance between studs, joists, bearers, trusses,
battens, purlins or other elements
3.1.47
span
unless otherwise specified, the centre-to-centre distance between the supports of a beam, truss,
joist, purlin, batten, rafter or roof

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3.1.48
stone wool
material made from stone or slag, spun into fibre-like structure
NOTE Available in different densities (expressed using the units, kg/m
3
) for use as insulation.
3.1.49
structural steel
all steel which forms part of the structure, including the roof construction, wall frame construction,
floor and ceiling supports
3.1.50
studs
vertical members of the light steel wall frame
NOTE Studs could be load-bearing, or not (see figures 2 and 4).
3.1.51
subfloor
lower layer of timber, concrete or fibre cement flooring to which the bottom wall plate and wearing
surface is attached
3.1.52
suspended floor
floor supported by beams or columns
3.1.53
tenancy-separating wall/floor
wall or floor that separates one residential unit from another
3.1.54
thermal break
air gap or layer of insulating material between two building components to reduce the transfer of
heat by conduction
3.1. 55
thermal efficiency
ability of a composite building component or assembly (floor, wall, ceiling or roof) to resist heat
transfer
3.1.56
top wall plate
member running along the top of a wall frame (see figures 2 and 4)
3.1.57
TRH
technical recommendations for highways
3.1.58
truss
latticed frame supporting the roof and ceiling over the full width of the domestic dwelling (see
figures 2 and 3)
3.1.59
uncontrolled airflow
unintended movement of air into or through a room or a building

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3.1.60
vapour permeable membrane
membrane installed to prevent or minimize the ingress of moisture and uncontrolled airflow, and
allow the passage of vapour
3.1.61
wall tie
bracket or wire connecting brick veneer cladding to the steel frame
3.1.62
weatherproofing
measures taken to prevent the ingress of moisture and to minimize uncontrolled airflow
3.1.63
web member
element of a truss or open web joist other than the top and bottom chord (see figures 2 and 3)
Figure 2 — Typical framing

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a) Typical roof truss assembly
b) Typical panel roof assembly
Figure 3 — Typical roof assemblies

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Stud spacing
Lowerstorey
Studheight
Lower storey
top plate
Lower storey
bottom plate
Lower storey
common stud
Floor joist
spacing
Rafter / Truss
spacing
Upperorsinglestorey
Studheight
Upper or single
Storey top plate
Upper or single
storey bottom plate
Upper or single
storey common stud
Nogging
Drg.740g
Figure 4 — Components of a typical wall assembly

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Figure 5 — Single or upper storey lintel

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Lintel
Sill trimmer
Lintel span
Jamb stud
Floor joist
spacing
Drg.740i
Figure 6 — Lower storey lintel

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Figure 7 — Components of a typical floor frame
Load-bearing or
non-load-bearing wall
parallel to floor joist
Load-bearing or
non-load-bearing wall
perpendicular to
floor joist
Drg.740k
Figure 8 — Typical wall arrangement

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Roof bracing
Drg.740l
Figure 9 — Typical roof bracing
'K' brace
Double diagonal
metal strap brace
Sheet brace
(FC sheet,
hardboard, plywood
or steel)
Drg.740m
Figure 10 — Typical wall bracing systems

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3.2 Symbols
A summed area supported by a structural member
cp resultant coefficient for internal and external wind pressure
cpe coefficient for external wind pressure
cpi coefficient for internal wind pressure
cr terrain roughness factor
d distance between points
G permanent load (own weight of building)
H height
L span or length
qk uniformly distributed imposed load
Qk concentrated imposed load
qp peak wind pressure
s spacing of elements
vb basic wind speed
w wind pressure
W wind load
Wr wind load on roof
Ww wind load on wall
W(down) downward-acting wind load
W(up) upward-acting wind load
α roof slope
Δ deflection
ρ air density

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4 Materials
4.1 General
Materials that have been proven to meet the requirements of the relevant national legislation (see
foreword), if used appropriately in combination with other materials, and installed to an acceptable
quality of workmanship, are listed as being ‘acceptable’ in this section. Other materials and
combinations of materials may be used if information derived from authoritative sources can be
provided to demonstrate that the requirements of the relevant national legislation (see foreword) are
met in all respects.
A building element or building component shall comply with the requirements for stability, integrity
and insulation when tested in accordance with the relevant provisions of SANS 10177-2.
4.2 Steel
Steel, either hot rolled or cold formed, used for the structures of light steel frame buildings, shall
comply with the requirements of an internationally recognized standard and shall have a coating at
least equivalent in corrosion resistance and robustness to 200 g/m2
galvanising (Z200) or a
150 g/m2
aluminium-zinc coating (AZ150).
Light structural steel members shall be manufactured using the prescribed steel strength grade (for
example, 300 MPa or 550 MPa minimum yield strength) in accordance with the design specification.
The material shall comply with the requirements of SANS 3575 or SANS 4998 (or both), or
SANS 9364.
All steel used shall have sufficient formability to allow the cold forming of profiles without any
cracking of the steel substrate.
Steel elements shall comply with the dimensional and straightness tolerances given in 5.13.1.
4.3 Fasteners
Fasteners, connectors and fixing methods for the steel structure shall comply with
a) SANS 1700 (all parts) for bolts, nuts and screws (self-drilling or self-tapping (or both)), as
relevant,
b) the manufacturer’s recommendations, supported by international standards,
c) specifications for clinching or other mechanical means of fastening as recommended by the
manufacturer, supported by international standards or specifications.
Carbon steel fasteners shall be coated with a zinc or inorganic coating (or both) to provide corrosion
protection similar, under the prevailing conditions, to the metallic coated steel sheet used for the
light steel cold-formed sections (for example coating designation Z275). (See 5.14.)
4.4 Interior lining of walls and ceilings
The materials shall comply with
a) SANS 266 for gypsum plasterboard, and
b) SANS 803 for fibre cement board (subject to fire rating requirements).

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4.5 Exterior cladding of walls (excluding masonry)
a) SANS 803 for fibre cement board, and
b) SANS 3575 or SANS 4998 for galvanized steel sheet.
4.6 Masonry for exterior cladding of walls and foundation walls
a) SANS 227 for clay bricks, and
b) SANS 10249 for cement blocks.
4.7 Thermal and acoustic insulation
a) SANS 1381-1 for fibre thermal insulation mats,
b) SANS 1381-6 for loose fill thermal insulation,
c) SANS 1381-4 for reflective foil laminates,
d) acceptable flame retardant grade expanded or extruded polystyrene, and
e) SANS 1383 for rigid polyurethane foam and poly-isocyanurate.
4.8 Damp-proof courses
a) SANS 248 for bituminous damp-proof courses, and
b) SANS 952-1 and SANS 952-2 for polyolefin film. Amdt 1
4.9 Wall ties and fixings
a) SANS 675 for galvanized wire, and
b) SANS 4998, SANS 3575 or SANS 9364 for zinc or aluminium-zinc coated steel strap.
4.10 Sheathing to prevent racking
The material shall comply with ASTM D 7033 for orientated strand board (OSB).
4.11 Vapour permeable membranes
The material shall comply with ASTM E 1677 for air retarder material or system for framed building
walls. Amdt 1

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4.12 Reinforced concrete
The material shall comply with SANS 10100-2 for reinforced concrete.
4.13 Holding down devices
a) SANS 3575 for brackets and washers made from galvanized steel sheet, with minimum coating
designation Z200, and
b) SANS 9364 for brackets and washers made from aluminium-zinc coated material, with minimum
coating designation AZ150.
4.14 Floors
a) SANS 803 for fibre cement boards,
b) ASTM D 7033 for OSB board (structural), and
c) SANS 10100-2 for structural concrete.
5 Steel structure
5.1 Basis for design
5.1.1 General
The structure shall resist all the loads the building will be subjected to, including loads deriving from
its own mass. However, the lateral support provided to steel elements by the non-structural
elements of the building, such as the wall or roof cladding or the ceilings, may be taken into account
in the design of these elements, provided that it can be demonstrated that the non-structural
elements have adequate strength for lending such support, and that the steel structure will not be
subjected to loads its elements cannot resist without such lateral support while the non-structural
elements are, for whatever reason, not in position.
A clear path shall be discernable for every force, from where the force acts to the foundations, and
all members and connections along this path shall have adequate strength and stiffness to resist
the forces generated in them without failure, or deflections that exceed the maximum deflections
specified in this standard.
The system effect as described in annex B may be taken into account in the design of systems of
beams or other bending elements with crossing members that can distribute load between the
beams.
5.1.2 Durability
The design criteria are based on the assumption that the materials used and their installation and
maintenance will ensure that components fulfil their intended structural function for the intended life
of the structure. (See 5.14.)

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5.2 Resistances of structural elements and connections
5.2.1 Design standard
Cold-formed steel components shall be designed to meet the requirements of SANS 10162-2,
except where expressly specified differently in this standard. Hot-rolled steelwork shall be designed
to comply with the requirements of SANS 10162-1.
5.2.2 Design properties
The yield stress and ultimate strength of the steel shall, except for steel with a minimum yield stress
of 550 MPa, be taken as the listed yield stress and ultimate tensile strength for that grade of steel in
the applicable standard (see 4.2). The yield stress and ultimate strength of any steel for which the
mechanical properties cannot be proved by means of a mill test certificate shall not be taken as
higher than 200 MPa and 365 MPa, respectively.
Steel with a minimum yield stress of 550 MPa and of elongation less than 8 % may not be used in
base metal thicknesses exceeding 0,90 mm. For such steel in base metal thicknesses of not less
than 0,60 mm, the yield stress and tensile strength shall both be taken as 495 MPa, while for base
metal thicknesses less than 0,60 mm the yield stress and tensile strength shall both be taken as
410 MPa. The properties of the steel may be determined as described in SANS 10162-2.
It is customary in South Africa to refer to the coated thickness of galvanized steel sheet as the
thickness of the sheet. As the coating does not add to the strength of the material, designers shall
work with the base metal thickness as the thickness, determined as follows:
Bt = Ct − 0,04 mm
where
Bt is the base metal thickness, expressed in millimetres;
Ct is the coated metal thickness expressed in millimetres.
The dimensions of a steel section shall be taken as the specified dimensions, which shall be used
to derive the section properties.
Due allowance shall be made for holes, cutaways and other ways in which the strength of an
element may be impaired, including holes made during or after erection in the structure to
accommodate services, in accordance with 5.7.1 and 5.8.2.1 and 7.2.
5.3 Design actions
5.3.1 General
Structural design actions and combinations of actions, in general, shall be in accordance with
parts 1 to 3 and part 8 of SANS 10160. The simplified actions described in 5.3.2 to 5.3.4 (inclusive),
may be used where appropriate. Amdt 1
Construction loads may become critical on some components of an unfinished building and in such
cases shall be accounted for in the design.
Where loads other than those specified in 5.3 (such as snow loads, seismic loads, or load
combination(s) containing such loads) are applicable, they shall be accounted for in the design.

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5.3.2 Imposed loads for domestic dwellings
For the design of domestic dwellings as defined in 3.1.17, the following characteristic imposed loads
may be used, with the uniformly distributed load and the concentrated load not necessarily
occurring simultaneously:
a) For roofs, not accessible except for normal maintenance:
Uniformly distributed load (qk): 0,5 kPa for contributory areas < 3 m2
;
0,25 kPa for contributory areas > 15 m2
; interpolate in-between;
Concentrated load (Qk): 1,0 kN applied anywhere.
b) For general floor areas:
Uniformly distributed load (qk): 1,5 kPa, but if the area A supported by a single column, wall,
beam or girder exceeds 20 m2
;
≥
⎧ ⎫
⎨ ⎬
⎩ ⎭
q
A
k
3,1
= 0,3 + 1,5 0,75 kPa
Concentrated load (Qk): 1,5 kN.
c) Balconies and roofs used for floor type activities 1,0 m or more above ground:
Uniformly distributed load (qk): 4,0 kPa;
d) Lateral horizontal loads applied to balustrades on balconies:
Uniformly distributed load: 0,5 kN/m applied at the top of the balustrade;
Concentrated load: 1,0 kN applied at the top of the balustrade.
5.3.3 Wind loads
5.3.3.1 General
The wind loads used in the design of buildings meeting the geometric limitations of figure 1 may be
calculated in accordance with 5.3.3.2 and 5.3.3.3.
5.3.3.2 Peak wind speed pressure
The peak wind speed pressure qp, expressed in kilopascals, shall be determined using equation (1).
ρq c v
2
p r b,0
1
. (1,4
2 000
= ) (1)
where
ρ is the air density, expressed in kilograms per cubic metre;
NOTE The recommended values of density as a function of altitude above sea level are given in table 1.

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cr is the terrain roughness factor and should be taken as follows:
cr = 0,71 for a structure within a built-up suburb which does not rise significantly above
the structures and objects on all sides of it;
cr = 0,98 for a structure in a more exposed situation;
cr = 1,09 for an exposed structure located less than 3 km from the coastline;
vb,0 is the fundamental value of the basic wind speed corresponding to the specific
geographical location, which shall be taken from figure 11.
Table 1 — Air density as a function of site altitude
1 2
Site altitude above
sea level
Air density ρ
m kg/m
3
0 1,20
500 1,12
1 000 1,06
1 500 1,00
2 000 0,94

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Amdt 2
Figure 11 — Geographic regions related to wind speeds

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5.3.3.3 Wind pressure on surfaces
5.3.3.3.1 General
Wind load on structures and structural elements shall be determined taking into account the
simultaneous action of external and internal wind pressures.
The net pressure on a wall, roof or other element is the difference between the pressures on the
opposite surfaces taking due account of their signs. Pressure directed towards the surface is taken
as positive, and suction, directed away from the surface, is taken as negative.
5.3.3.3.2 Internal wind pressure
For a building without a wall with a dominant opening, the internal pressure coefficient cpi shall be
taken as +0,2 or −0,3, whichever causes the more severe loading in combination with the
appropriate external wind pressure.
For a building with a dominant opening in the windward wall, the internal pressure coefficient cpi
shall be taken as +0,75. If this dominant opening can be assumed to be closed during storm
conditions, the internal pressure coefficient cpi may be taken as +0,6.
A wall shall be regarded as containing a dominant opening if the area of its openings is at least
twice the sum of the area of openings and leakages in the remaining exterior walls of the building.
The wind pressure, w (expressed in kilopascals), on walls and ceilings in the building shall be
determined using equation (2) and the appropriate internal pressure coefficient cpi, as defined
above.
w = qp·cpi (2)
where
qp is the peak wind speed pressure, in accordance with 5.3.3.2;
cpi is the pressure coefficient for the internal pressure.
5.3.3.3.3 External wind pressure on walls
The external pressure coefficients cpe for buildings and parts of buildings depend on the size of the
loaded area A, which is the tributary area of the structure that produces the wind action effect in the
structural component to be calculated. The external pressure coefficients are given for loaded areas
of 1 m2
and 10 m2
in the tables for the appropriate building configurations as cpe,1 for local
coefficients, and cpe,10 for overall coefficients, respectively.
Values for cpe,1 are intended for the design of small elements and fixings with an area per element
of 1 m2
or less, such as cladding or roofing elements. Values for cpe,10 may be used for the design of
the overall load-bearing structure of buildings.
The external pressure coefficients cpe for the walls of a building with a rectangular plan shall be
obtained from figure 12. The definition of the zones on the walls of the building is given in figure 12.
The external wind pressure we (measured in kilopascals) on the vertical walls of the building shall
be determined using equation (3) and the appropriate external pressure coefficients as defined in
figure 12.
we = qp·cpe (3)

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where
qp is the peak wind speed pressure;
cpe is the pressure coefficient for the external pressure.
b = plan dimension of the building perpendicular to the wind direction
d = plan dimension of the building along the wind direction
e = 0,2b or 0,4h, whichever is the smaller Amdt 1
h = eaves height of the building
Plan view of rectangular building
1 2 3 4 5
Coefficient
Zone
A B C D
Values of external pressure coefficient
cpe
cpe,1 −1,4 −1,1 +1,0 −0,5
cpe,10 −1,2 −0,8 +0,8 −0,5
Figure 12 — Key for vertical walls of rectangular plan buildings
5.3.3.3.4 Resultant wind pressure
The resultant wind pressure w on walls or roofs is the sum of the internal and external wind
pressures, and shall be calculated using equation (4) and the appropriate internal and external
pressure coefficients as defined in figure 12.
w = qp (Cpe + Cpi) (4)
where qp, cpi and cpe are as defined for equations (2) and (3).

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5.3.3.3.5 Wind pressure on roof overhangs
The pressure on the underside of the roof overhang is equal to the pressure for the zone of the
vertical wall directly connected to the overhang; the pressure at the top side of the roof overhang is
equal to the pressure of the zone, defined for the roof (see figure 13).
Figure 13 — Illustration of relevant pressures for roof overhangs
5.3.3.3.6 External wind pressure on mono-pitch roofs
The roof, including protruding parts, shall be divided into zones as shown in figure 14, with b always
the across wind plan dimension of the building.
Side view Side view
Plan view for wind θ = 0° and θ = 180° Plan view for wind θ = 90°
e = 0,1b or 0,2h, whichever is smaller
Figure 14 — Key for mono-pitched roofs

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The external wind pressure coefficient for mono-pitched roofs shall be obtained from table 2.
The wind pressure, w (expressed in kilopascals), on the mono-pitched roof of the building shall be
determined using equation (4) and the appropriate external and internal pressure coefficients as
defined in table 2.
Table 2 — External pressure coefficient cpe for mono-pitched roofs
1 2 3 4 5 6 7
Roof pitch
Local coefficient Overall coefficient
Cpe,1 Cpe,10
Wind direction
0˚ or 180˚ – 90˚ 0˚ or 180˚ – 90˚
Zone
degrees E (edge) F G (edge) E (edge) F G (edge)
5 −2,0 −1,2 −2,0 −1,3 −0,8 −1,8
or
a
0,0 0,0 0,0 0,0
15 −2,0 −1,2 −2,5 −1,3 −0,9 −1,9
or
a
0,2 0,2 0,2 0,2
30 −1,5 −0,8 −2,0 −0,8 −0,8 −1,5
or
a
0,7 0,4 0,7 0,4
45 −0,7 −0,5 −2,0 −0,7 −0,5 −1,4
or
a
0,7 0,6 0,7 0,6
a
At wind direction of θ = 0° the pressure changes rapidly between positive and negative
values around a pitch angle of α, accordingly both positive and negative values are
given. For such roofs, two cases should be considered: one with all positive values, and
one with all negative values. Positive and negative values cannot act in combination on
the same face.
Amdt 2
5.3.3.3.7 External wind pressure on duo-pitched roofs
The roof, including protruding parts, shall be divided into zones as shown in figure 15.
The external wind pressure coefficients for the duo-pitched roofs shall be obtained from table 3.
The wind pressure w (expressed in kilopascals), on the duo-pitched roof building shall be
determined using equation (4) in 5.3.3.3.4 and the appropriate external and internal pressure
coefficients as defined in 5.3.3.3.2 and 5.3.3.3.7.

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e = 0,1h or 0,2h, whichever is the smaller
Figure 15 — Key for duo-pitched roofs
Table 3 — External pressure coefficients cpe for duo-pitched roofs
1 2 3 4 5 6 7 8 9 10 11
Roof pitch
Local coefficient Cpe,1 Overall coefficient Cpe,10
Wind direction
0˚ or 180˚ 90˚ 0˚ or 180˚ 90˚
Zone
degrees G (edge) H J K (edge) L G (edge) H J K (edge) L
5 −2,0 −1,2 −0,6 −2,0 −1,2 −1,2 −0,6 −0,6 −1,3 −0,7
or
a
0,0 0,0 +0,2 0,0 0,0 +0,2
15 −1,5 −0,3 −1,5 −2,0 −1,2 −0,8 −0,3 −1,0 −1,3 −0,6
or
a
0,2 0,2 0,0 0,2 0,2 0,0
30 −1,5 −0,2 −0,5 −2,0 −1,2 −0,5 −0,2 −0,5 −1,4 −0,8
or
a
0,7 0,4 0,0 0,7 0,4 0,0
45 0,0 0,0 −0,3 −2,0 −1,2 0,0 0,0 −0,3 −1,4 −0,9
or
a
0,7 0,6 0,0 0,7 0,6 0,0
a
For the across wind situation the pressure changes rapidly between positive and negative values on
the windward face depending on the roof pitch α, accordingly both positive and negative values are
given. For such roofs, four loading cases shall be considered, where the largest or smallest values of
all areas G and H are combined with the largest or smallest value in area J. Positive and negative
values cannot act in combination on the same face.
Amdt 2

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5.3.3.3.8 Local wind pressure at corners of roofs
The local external pressure coefficient for the square extending for 2 m in both directions
horizontally from the corners of a roof shall be taken as −2,9. This pressure coefficient shall be used
in conjunction with the pressure on the underside of the roof for the design of purlins, battens and
sheeting and their fixings in this area.
5.3.4 Actions during construction
Critical loads and combinations of loads during construction may be different from those for the
complete structure. These include:
a) Imposed load arising from the stacking of construction materials.
b) Imposed load arising from people working on the incomplete frame.
c) The wind load during construction may be based on a design wind speed with a mean return
period of 10 years. The wind load effects on the incomplete structure may be different from that
on the complete structure, for example, supported walls may become free standing walls during
construction, or roof sheeting in the internal zone of a roof could become edge sheeting, and
therefore need temporary bracing.
d) Unbalanced loads arising during construction.
e) Loads on roofs during construction:
uniformly distributed load (qk): 0,50 kPa for contributory areas < 3,0 m2
, or 0,25 kPa for
contributory areas > 15 m2
, with linear interpolation in-between;
5.4 Design criteria
5.4.1 Strength and stability
The building as a whole, and its parts, shall be designed to prevent overturning, uplift, sliding or
excessive settlement, as well as failure of either the steel elements or the non-structural materials
by collapse, tearing, unacceptable cracking or local deformations.
The design load for the ultimate limit state shall be that combination of (factored) loads which
produce the most adverse effect on the building. For domestic dwellings as defined in
clause 3.1.17, the design loads may be determined from, but not limited to, the loads and load
combinations given in 5.6 to 5.8 (inclusive).
NOTE Only combinations of actions usually deemed as potentially critical have been included in the design
criteria in sections 5.6 to 5.8 (inclusive). SANS 10160-1 and SANS 10160-2 provide further information for
other situations. Amdt 1
5.4.2 Serviceability
The design criteria for serviceability shall be taken from, but not limited to, the criteria given in
sections 5.6 to 5.8 (inclusive).
NOTE The design criteria have been determined on the basis of experience. The serviceability limits are
intended to provide satisfactory service for typical situations. SANS 10160-1, SANS 10160-2, SANS 10160-7
and SANS 10160-8 provide further guidelines for other situations. Amdt 1

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5.5 Methods of assessment of resistances
5.5.1 General
The assessment of the resistance to loads of a structural element or structural assembly shall be
carried out by one of the following methods:
a) calculation;
b) testing; or
c) combination of calculation and testing.
5.5.2 Calculations
Calculations shall be based on appropriate structural models for the ultimate or serviceability limit
states under consideration. The method of structural analysis shall take into account equilibrium,
stability and geometric compatibility. The combinations of loads shall include all appropriate
combinations outlined in this document. The design properties for steel shall be in accordance with
5.2.2. The design capacities of steel elements shall be determined in accordance with
SANS 10162-1 or SANS 10162-2.
5.5.3 Testing
Only prototype testing of full size members or sub-assemblies in accordance with 5.11 shall be
used in assessment.
5.5.4 Combination of calculation and testing
A combination of testing and calculation based on appropriate structural models can be used in
assessment.
5.6 Roof members
5.6.1 General
All roof members including purlins or roof battens, roof trusses or rafters, ceiling brandering and
bracing (see figure 3) shall be designed to act together as a structural unit to transfer all the loads
imposed on the roof, including forces resulting from the fact that the roof provides lateral support to
the walls under the action of wind load (see 5.10.2.1), to appropriate supports.
All other roof members not specifically mentioned herein shall be designed in accordance with the
same principles as those mentioned herein.
5.6.2 Roof battens and purlins
5.6.2.1 Design for strength
The combinations used for the determination of the design load effects for strength are:
1,2 Gk + 1,6 Qk
1,2 Gk + 1,6 qk
0,9 Gk + 1,3 Wk(up)

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1,2 Gk + 1,3 Wk(down)
where
Gk are the permanent loads including the weight of roofing, purlins or battens and
insulation;
Wk is the wind load derived from w in 5.3, taking both the external and internal wind
pressures into account;
Qk and qk are the imposed load as in 5.3. For inaccessible roofs, it may be assumed that the
concentrated load Qk is shared equally between two adjacent battens provided
their spacing does not exceed 400 mm.
NOTE Guidance on the determination of weights can be found in annex A.
5.6.2.2 Design for serviceability
For satisfactory performance under each issue of concern, the calculated value of the serviceability
parameter under the nominated load(s), shall be kept within the limiting value of the response, as
shown in table 4.
Table 4 — Serviceability response limits — Roof battens and purlins
1 2 3 4 5
Issue of
concern
Serviceability
parameter
Factored
load
Limit of
response
Application
Visual sagging
Mid-span deflection (Δ)
1,1 Gk
L/300
Batten
or
purlin
Cantilever deflection (Δ) L/150
Deflection under
imposed load
Mid-span deflection (Δ) 1,0 Qk
or 1,0 qk
L/150
Deflection under
wind load
0,6 Wk
L/150
L = span of batten or purlin, expressed in millimetres
Gk, Qk, qk and Wk = as in 5.6.2.1
NOTE For flat or near flat roofs (slope less than 3°), the effects of ponding should be
considered.
5.6.3 Roof trusses or rafters
The combinations used for the determination of the design load effects for strength are:
1,2 Gk + 1,6 qk
1,2 Gk + 1,6 Qk
0,9 Gk + 1,3 Wk(up)
1,2 Gk + 1,3 Wk(down)

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where
Gk are the permanent loads of the complete roofing system including the weight of
roofing, purlins or battens, insulation, ceilings, brandering, trusses or of services as
appropriate;
Wk is the wind load derived from w in 5.3.3, taking both the external and internal wind
pressures into account;
Qk and qk are imposed loads as in 5.3.3.
NOTE Guidance for the determination of weights can be found in annex A.
The concentrated load Qk need not be applied to the web members of trusses.
For satisfactory performance under each issue of concern, the calculated value of each parameter
in table 5 shall be kept within the limiting value of the response, under the action of the appropriate
load.
Table 5 — Serviceability response limits — Trusses and rafters
1 2 3 4 5
Issue of concern
Serviceability
parameter
Factored
load
Limit of
response
Application
Visual sagging Mid-span deflection (Δ) 1,1 Gk L/300 Truss top chord or rafter
Cracking of ceiling Mid-span deflection (Δ) Qk d/250
Truss bottom chord or
ceiling joist
Deflection under
imposed load
1,0 Qk or
1,0 qk
d/200 or
L/250, whichever
is less
Truss or rafter
Deflection under
wind load
Mid-span deflection (Δ) 0,6 Wk L/150 Truss or rafter
Undulation of roof
Differential mid-span
deflection (Δ)
1,1 Gk
s/150
(< 4 mm)
Differential deflection
between adjacent
trusses or rafters
d = distance between nodal points, expressed in millimetres
s = spacing between trusses
L = span of truss or rafter, expressed in millimetres
Gk, Qk, qk and Wk = as in 5.6.2.1
NOTE For cantilevers, the limit of response may be taken as twice that of the mid-span deflection where
L is the projection of the cantilever.
5.6.4 Ceiling brandering
The load combinations used for the determination of the design load effects for strength are:
0,9 Gk + 1,3 Wk(up)
1,2 Gk + 1,3 Wk(down)

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where
Gk are the permanent loads of the brandering, ceiling and insulation;
Wk is the wind load resulting from internal pressure, from 5.3.3.
NOTE Brandering need not be designed to resist imposed loads, on the assumption that nobody will be
allowed to stand on the brandering.
For satisfactory performance under each issue of concern, the calculated value of the parameter
under the nominated load shall be kept within the limiting value of the response, as shown in
table 6.
Table 6 — Serviceability response limits — Brandering
1 2 3 4 5
Issue of concern
Serviceability
parameter
Factored load
Limit of
response
Application
Sag or ripple Mid-span deflection (Δ) 1,1 Gk L/300 All ceilings
Cracking of ceiling Mid-span deflection (Δ) Gk + 0,6 Wk L/200 Ceilings with plaster finish
L = span of brandering, expressed in millimetres
Gk and Wk = as in 5.6.4.1
5.6.5 Roof connections and roof bracing
Connections in the roof structure shall be designed in accordance with 5.9. Roof bracing shall be
designed in accordance with 5.10.2.
5.7 Wall elements
5.7.1 General
All wall elements including load-bearing wall studs, wall plates, posts, lintels and bracing
(see figures 2 and 4) shall be designed to act together as a structural unit to transfer all the loads
imposed on the roof and walls to appropriate supports.
Noggings, if required to provide lateral supports for the studs, for fixing of external cladding or
internal lining, or for the support of items attached to the wall, shall be designed to suit their
intended purposes.
Wall studs may not be spaced more than 610 mm apart. Structural requirements, the strength of the
cladding materials, non-structural considerations and the dimensions of available cladding
materials, may necessitate closer spacing. Amdt 2
Flanges of studs may not be notched to accommodate services, unless expressly specified in the
design. The following rules shall be observed with respect to penetrations through stud webs, and
the design shall allow for such penetrations to be made:
a) A rectangular or oval hole or slot shall not exceed 40 % of the overall depth of the member. The
length of the hole shall not exceed three times the width of the hole.
b) The diameter of a circular hole shall not exceed 50 % of the depth of the member.

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c) A hole of which any dimension exceeds 15 mm shall not be closer to an end of a stud than
2,5 times the overall depth of the stud.
d) Any two holes shall be spaced further apart than 2,5 times the largest dimension of either of the
two holes.
e) All holes shall be located along the centre line of the steel member.
5.7.2 Load-bearing wall studs
5.7.2.1 General
Load-bearing wall studs include
a) common studs that support the vertical loads applied to the top wall plate by rafters, trusses and
ceiling joists, and horizontal loads due to wind,
b) jamb studs that are provided on each side of an opening to support loads from the lintel over the
opening as well as the horizontal wind load across the width of the opening, and
c) studs supporting concentrated loads, which are installed in addition to common studs (or jamb
studs) to carry concentrated vertical loads arising from principal roof or floor supporting
members.
Load-bearing wall studs shall be designed to carry the tension or compression loads from supported
floors or roofs, and also to carry horizontal wall loads, and to transfer these loads to the top and
bottom wall supports.
Wind load effects on studs include a combination of axial loads from wind pressure on roofs and
uniformly distributed lateral loads from wind pressure on walls.
5.7.2.2 External load-bearing wall studs for a single storey or upper storey of a two storey
construction
5.7.2.2.1 Design for strength
The load combinations for the determination of the design load effects for the strength of wall studs
are:
1,2 Gk + 1,6 qk
1,2 Gk + 1,6 Qk
1,2 Gk + 1,3 (Wkw + Wkr(down))
0,9 Gk + 1,3 (Wkw + Wkr(up))
where
Gk is the self-weight of the roof, including roof structure, roof cladding, roof battens,
ceiling battens, ceiling, services and roof insulation if appropriate;
qk and Qk are the imposed loads on the roof;
Wkw is the wind load normal to the wall;

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Wkr is the wind load on the roof.
NOTE Wall studs may also be subject to additional axial forces if they are part of the bracing system
resisting racking forces.
5.7.2.2.2 Design for serviceability
under the nominated load shall be kept within the limiting value of the response in table 7.
Table 7 — Serviceability response limits — External walls, single or upper storey
1 2 3 4 5
Issue of concern
Serviceability
parameter
Load
Limit of
response
Application
Discernable movement Mid-height deflection (Δ) 0,6 Wkw
H/150
(< 20 mm)
Face loading
Impact Mid-height deflection (Δ) Q
H/200
(< 12 mm)
Soft body impact on wall
Wkw = wind load normal to wall
Q = 0,7 kN
H = height of the stud, expressed in millimetres
5.7.2.3 External load-bearing wall studs for the lower storey of a two storey construction
5.7.2.3.1 Design for strength
The load combinations used for the determination of the design load effects for the strength of wall
studs are:
1,2 Gk + 1,6 Qk
1,2 Gk + 1,6 qk
0,9 Gk + 1,3 (Wkw + Wkr(up))
where
Gk is the self-weight of the roof, including the roof structure, roof cladding, roof
battens, ceiling battens, ceiling, upper storey walls, upper storey floor, services and
roof insulation, if appropriate;
qk and Qk are the imposed loads on the roof and upper storey floor;
Wkw is the wind load normal to the wall;
Wkr is the wind load on the roof.

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5.7.2.3.2 Design for serviceability
under the nominated load shall be kept within the limiting value of the response in table 8.
Table 8 — Serviceability response limits — External walls, lower of two storeys
1 2 3 4 5
Issue of concern
Serviceability
parameter
Load
Limit of
response
Application
Discernable movement Mid-height deflection (Δ) 0,6 W
H/150
(< 20 mm)
Face loading
Impact Mid-height deflection (Δ) Q
H/200
(< 12 mm)
Soft body impact on wall
H = height of lower storey
W = either Wkw or Wkr in 5.7.2.3.1
Q = 0,7 kN
NOTE Jamb studs may warrant specific serviceability criteria to counteract the closing and slamming
of doors. Brittle lining materials, such as ceramic tiles, may require special consideration for
serviceability. Brick veneer should not be considered as a brittle cladding material under this definition.
5.7.2.4 Internal load-bearing wall studs
Design criteria for internal load-bearing wall studs are similar in principle to external load-bearing
wall studs. Wind load normal to the wall is limited to differential pressure between the wall faces and
may be taken as 0,3 qp where qp is obtained from 5.3.3.2.
5.7.3 Non-load-bearing studs
5.7.3.1 General
Non-load-bearing studs are defined here as wall studs that are not required to carry gravity loads,
other than their own self-weight. These studs are, however, expected to carry any lateral loads such
as wind loads, impact loads or internal pressures they may be subjected to and shall be designed
accordingly.
The top wall plate of a non-load-bearing wall shall be laterally supported.
Joints shall be made in non-load-bearing walls where they cross movement joints in the main
structure.
Care shall be taken to ensure that non-load-bearing studs do not become load-bearing because of
deflection of a floor above it. This can be achieved by measures similar in concept to those depicted
in figure 16. The finishes shall be detailed so as not to be damaged by the resulting movements.

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Channel fixed to
structure over top
wall plate
Top wall plate not
attached to channel
Drg.740v
Figure 16 — Measures to prevent loading of non-load-bearing studs
Non-load-bearing studs have to resist wind loads and shall be designed in the following way:
a) External non-load-bearing studs shall be designed for the full wind load normal to the wall.
b) Internal non-load-bearing studs shall be designed for the differential pressure between the sides
of the wall, which may be taken as 0,3 qp, where qp is obtained from 5.3.3.2.
The serviceability requirements for non-load-bearing studs are the same as those for load-bearing
studs (see 5.7.2).
5.7.4 Noggings
Noggings shall be designed to provide lateral and torsional restraints to the studs. In addition,
noggings shall be designed to support an imposed concentrated vertical gravity load of 1,0 kN
placed anywhere on its span to produce the maximum load effects during construction.
Noggings are not normally required for non-load-bearing walls, except where required for the fixing
of cladding in accordance with recommendations of the manufacturers of the cladding material.
5.7.5 Lintels and wall plates for load-bearing walls
5.7.5.1 Wall plates
Load-bearing wall plates are designed to transfer vertical loads only. Wall plates are generally not
designed to transfer horizontal loads laterally to support walls, as ceiling and floor diaphragms are
designed to resist horizontal loads and give lateral support to walls.
Load-bearing wall plates shall be designed to resist the vertical loads exerted by the elements
resting on them, except where such loads are transferred directly into the supporting structural
elements below the wall plate, aligned with the supported elements.
Wall plates may also have to resist longitudinal forces resulting from wall bracing (see 5.10.3).

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5.7.5.2 Lintels
A lintel shall be provided to any opening in a load-bearing wall where one or more studs are cut or
displaced to form the opening. A lintel is not required where an opening falls between studs.
Lintels are designed to transfer the vertical loads applied over the opening, to the jamb studs on the
sides of the opening.
Lintels in single or upper storey walls are designed to support rafters, trusses or any other load
carrying members that are located over the opening (see figure 5).
Lintels in the lower storey walls of a two-storey construction are designed to support the loads from
the wall above including the roof loads and the floor loads from the storey above (see figure 6).
A lintel can be designed as part of a system that includes top wall plates and other structural
components located directly above an opening and connected to the lintel.
Elements at the level of the top wall plate are not normally designed to carry the wind load normal to
the wall arising from the opening. Elements at the level of a ledger (see figure 2) shall be able to
span horizontally between the jamb studs when the wall is subjected to wind loads.
The load combinations for the determination of the design load effects for wall plates and lintels are:
a) Single or upper storey
1,2 Gk + 1,6 qk
1,2 Gk + 1,6 Qk
0,9 Gk + 1,3 Wkr(up)
1,2 Gk + 1,3 Wkr(down)
where
Gk is the weight of the complete roof and ceiling;
qk and Qk are the imposed loads on the roof;
Wkr is the wind load on the roof;
Wkw is the wind load normal to the wall.
b) Lower storey
1,2 Gk + 1,6 qk
1,2 Gk + 1,6 Qk
0,9 Gk + 1,3 Wkr(up)
1,2 Gk + 1,3 Wkr(down)

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where
Gk is the weight of the complete roof, upper storey walls and floor, including the
ceiling;
qk and Qk are the imposed loads on the roof and upper storey floor;
Wkr is the wind load on the roof;
Wkw is the wind load normal to the wall.
under the nominated load shall be kept within the relevant limiting value of the response, as shown
in table 9.
Table 9 — Serviceability response limits for wall plates and lintels
1 2 3 4 5
Issue of concern
Serviceability
parameter
Load
Limit of
response
Application
Wall plates
Sagging or wind uplift Mid-span deflection (Δ)
Gk
or
0,9G + 0,6 Wkr(up)
L/200
(< 3 mm)
Relevant Gk for upper
storey and lower
storey top plates
Lintels
Sagging Mid-span deflection (Δ) Gk
L/300
(< 10 mm)
Relevant Gk for upper
storey lintel
Wind uplift Mid-span deflection (Δ) 0,9 Gk + 0,6 Wkr(up) L/200
5.7.6 Wall bracing
Wall bracing shall be designed in accordance with 5.10.3.
5.8 Floor members
5.8.1 General
All floor members including floor joists, bearers and flooring shall be designed to act together as a
structural unit to transfer all the loads imposed on the roof, walls and floors to appropriate supports.
In addition, the floor assembly is expected to act as a diaphragm to transmit the horizontal shear
action effects arising from wind actions.
5.8.2 Floor joists and bearers
5.8.2.1 General
Floor joists are designed mainly to support floor loads. Floor bearers are designed to support the
floor joists (see figure 7).

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Floor joists or bearers may also be required to support ceilings (of the storey below), and load-
bearing and non-load-bearing walls which may run either parallel or perpendicular to the direction of
the joists or bearers (see figure 8).
Floor joists or bearers shall be fixed to supporting wall plates and channel bearing stiffeners as
shown in figure 17. Alternatively, bridging as shown in figure 20, or similar elements, shall be
provided to prevent rolling.
Drg.740w
Figure 17 — Channel bearing stiffeners for joists or bearers
The flanges of joists or bearers may not be notched unless it is specified in the design.
Except where adequate strengthening is provided around a hole through the web of a joist or
bearer, the rules in 5.7.1 governing penetrations through studs shall also be observed for floor joists
and bearers.
Where joists overlap on a load-bearing intermediate wall as shown in figure 18, they should be fixed
together with bolts or screws situated near the ends of the overlapping parts to prevent the floor
decking being pushed up or the ceiling being cracked when the cantilevered parts of the joist move
upward. The length of the overlap shall be a minimum of 150 mm.
Flanges of joists or bearers may not be notched to accommodate services, unless expressly
specified in the design. The rules provided in 5.7.1(a) to 5.7.1(e) shall be observed with respect to
penetrations through webs, and the design shall allow for such penetrations to be made.

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Drg.740x
Figure 18 — Overlapping joists
The combinations of loads used for the determination of the design load effects for floor joists or
bearers are:
1,2 Gk + 1,6 qk
1,2 Gk + 1,6 Qk
where
Gk are the permanent combined loads supported by joists or bearers;
Qk and qk are the imposed loads as in 5.3.2.
The load effects of concentrated loads shall be considered where appropriate.
Where a joist or bearer is subjected to a point load deriving from a stud standing on it, it shall be
designed to resist the load resulting from that combination of loading that causes the load to be a
maximum.
For satisfactory performance under each issue of concern, the calculated value of each parameter
under the nominated load shall be kept within the appropriate limiting value of the response as
shown in table 10.

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Table 10 — Serviceability response limits — Floors
1 2 3 4 5
Issue of
concern
Serviceability
parameter
Load Limit of response Application
Noticeable sag Mid-span deflection (Δ)
qk L/450 Normal floor
systemGk + qk L/350 ≤ 15 mm
Vibration Mid-span deflection (Δ)
Gk + 0,2qk 5 mm
Dynamic
performance
of floor
1,0 kN Span Δ
Load shared among 2 to
3 joists for chipboard or
plywood floor, and 3 to
5 joists for concrete or
built-up acoustic floor
m mm
3,5
3,8
4,2
1,7
1,6
1,5
4,6
5,3
6,2
1,4
1,3
1,2
NOTE 1 Alternatively, a dynamic analysis can be performed with a loading of G + 0,2qk for which the
response limit is that the frequency should exceed 8 Hz.
NOTE 2 Mid-span deflection refers to the total floor system deflection.
NOTE 3 Limit of response for a cantilever may be taken as half of the values given above.
5.8.3 Floor and subfloor bracing
Floor and subfloor bracing and their connections shall be designed in accordance with 5.10.4.1
and 5.10.4.2.
5.9 Connections
5.9.1 General
Connection elements include connection components (frame anchors, brackets, straps, plates,
parts of members to be connected) and connectors (welds, bolts, screws, rivets, clinches, nails,
structural adhesives).
5.9.2 Design criteria
Connection components and connectors shall be designed to satisfy the following:
a) Connection elements shall be capable of resisting design load effects arising in the connection
as the result of the design load effects in the connecting members and their supports.
b) Deformations at the connection shall be within the acceptable limits.
c) Appropriate allowance shall be made for any eccentricity at the connection.
d) Appropriate allowance shall be made for any local effects at the connections (for example, stress
concentration and local buckling).
e) The uplift forces due to wind load shall be assessed and adequate tie-down shall be provided to
resist these forces.
f) The strength and serviceability of the connection shall be assessed by computation using
SANS 10162-2, if applicable, or by prototype testing in accordance with 5.11, or by information
supplied by the manufacturer, provided that proof can be provided that such information is based
on a comprehensive testing programme.

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5.10 Bracing
5.10.1 General
This section describes the requirements for the design of bracing. These include roof bracing, wall
bracing, and floor and subfloor bracing.
NOTE Temporary bracing may be required during construction.
5.10.2 Roof bracing
5.10.2.1 General
All roof members including roof battens or purlins, roof trusses or rafters, brandering and bracing
shall be designed to act together as a structural unit to transfer all the loads imposed on the roof to
appropriate supports. For lateral restraints, it is generally assumed that the roof battens or purlins
will provide the lateral support for the top chords of the trusses and the ceiling brandering will
provide the lateral support for the bottom chords of the trusses. These assumptions require
additional actions to ensure their validity, including:
a) provision of additional bracing such as cross braces to ensure that the assumptions are valid;
and
b) computation to verify the adequacy of the roof battens or purlins, and ceiling battens and their
connections to the trusses to act as lateral restraint members.
The roof structure shall form a diaphragm to provide lateral support to the walls and to ensure that
the shape in plan of the building is maintained under all loading conditions. The roof structure,
including battens, purlins, ties and bracing shall be designed to ensure that it can perform this
function, and transmit the forces to the wall bracing system. A planar ceiling consisting of panels
that are screwed to brandering may be considered to form a diaphragm of adequate strength for
this purpose, provided that the ceiling is firmly attached to both external and internal walls through
the structure.
5.10.2.2 Truss bracing
5.10.2.2.1 Top chord bracing (see figure 9)
The requirement for a top chord bracing system is to transfer the forces generated in the top chord
restraints (usually by battens or purlins) back to the supporting structures. The loads to be
considered are those required to restrain the top chord against buckling, which may be taken as
equal to 0,02 times the maximum compressive force in the top chord, in addition to the wind load
perpendicular to the span of the trusses, including the wind load on walls supported at the top chord
level. For bracing intended to support more than one truss the value 0,02 shall be replaced by
0,02 + 0,01(n – 1) ≤ 0,08
where n is the number of trusses supported.
Diagonal bracing shall be installed at an angle of between 30° and 60° to the truss top chord or
rafter, and it shall not sag more than 1/500 of the distance between supports. Where tension
devices are used to remove excessive sag, care shall be taken not to over-tension the braces.
5.10.2.2.2 Bottom chord bracing
Bottom chord bracing is required to restrain bottom chords against lateral buckling under wind uplift.
It shall be fixed to each truss and to the wall in the same manner as for top chord bracing.

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The loads to be considered are those required to restrain the bottom chord against buckling, which
may be taken as equal to 0,02 times the maximum compressive force in the bottom chord, as well
as wind load on walls supported at the bottom chord level.
A planar ceiling consisting of panels screwed to brandering, which is in turn screwed to the bottom
chords of the trusses, may be regarded as providing adequate bracing to these chords.
5.10.2.2.3 Web bracing
Where the truss design requires bracing of the web members, acceptable bracing, properly
supported and connected, shall be provided.
5.10.3 Wall bracing
5.10.3.1 General
Wall bracing is required to transfer all horizontal forces from the roof, walls and floors to the
appropriate suspended floor diaphragms and to the foundations. Typical wall bracing is shown in
figure 10. Portal frames made of hot-rolled steel may also be used for bracing. Alternatively, the
building may be tied to a strong and rigid vertical structure such as a concrete wall.
Metal strap bracing shall be fixed to each stud it crosses, only after the structure has been squared
up and plumbed and the bracing has been finally tensioned.
The design of the wall bracing shall conform to the following criteria:
a) The magnitudes of the forces shall be determined in accordance with 5.3 or with parts 1 to 8 of
SANS 10160. Amdt 1
b) Bracing shall be provided in two orthogonal directions and shall be distributed evenly so that no
torsional weakness is created (see figure 19).
c) If the strength of non-structural cladding is to be taken into account for the bracing of the building,
the design shall be based on full scale tests in accordance with 5.11 and the values in table 12,
and not more than 50 % of the bracing force may be assumed to be resisted by such cladding.
d) The angle of any metal strap bracing element shall be between 30° and 60° to the horizontal.
e) Sheet bracing elements shall not have an aspect ratio (height/width) greater than 3.
f) Appropriate anchoring of the braced panels shall be provided. Anchors in a concrete foundation
shall have a sufficient edge distance to ensure that the strength of the anchorage will be
adequate, and such anchors may only be installed into or attached to beams and slabs with
sufficient strength to resist the forces exerted by the anchors.
g) A combination of different systems for wall bracing may be used only if it can be established that
the systems have similar bracing stiffness or the performance is established by testing of a full
size prototype. Otherwise, the strength of the bracing shall be taken as that of only one of the
systems.
h) If a portal frame is used for bracing, the members and connections of the frame shall have
adequate strength to resist the moments and forces in the frame, and the lateral deflection of the
frame under full serviceability wind loads may not exceed h/200, where h is the height of the
portal frame.

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i) The racking strength of the system shall be established by either full size prototype testing or by
a rational analysis. Connection details shall be designed to resist the forces specified in 5.3 or
parts 1 to 8 of SANS 10160. Amdt 1
j) The braced panels shall be effectively attached to the roof and floor structures.
Figure 19 — Typical distribution of bracing walls
5.10.4 Suspended floor bracing
5.10.4.1 General
Suspended floors shall be designed to form a rigid plate that can provide lateral support to the walls
and ensure that the shape in the plan of the building is maintained under all loading conditions. If
the strength of the flooring is not adequate for resisting the forces acting on it and transmitting the
forces to the wall or subfloor bracing, or the rigidity is not sufficient for resisting deformation, bracing
in the plane of the floor shall be provided.
5.10.4.2 Floor joists or bearers
Floor joists rely on the floor decking to provide lateral restraint. Similarly, bearers rely on floor joists
to provide lateral restraint.
If the span of floor joists or bearers consisting of lipped channels or Σ-shaped channels exceeds
4 m, the joists should be secured against rolling at points along their length not further than 3 m
apart by bridging as shown in figure 20, or by another effective method.
All joists and bearers shall be secured against toppling or rolling at all supports.

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Figure 20 — Bridging for preventing rolling of floor joists
5.11 Testing
5.11.1 General
Tests of steel and steel elements or assemblies shall be carried out as specified in SANS 10162-2.
The design resistance of an element, connection or assembly may alternatively be determined by
testing. Only full size prototypes of an element, connection or assembly shall be used in tests.
5.11.2 Coefficient of variation
The coefficient of variation of structural characteristics (ksc), refers to the variability of the total
population of the production units. This includes the total population variation due to fabrication (kf)
and material (km). It can be approximated as follows:
2 2
sc f m= +k k k
Unless a comprehensive test program used to establish ksc shows otherwise, the value of ksc shall
be not less than the following:
a) member strength: 10 %;
b) connection strength: 20 %;
c) assembly strength: 20 %;
d) member stiffness: 5 %;
e) assembly stiffness: 10 %.

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5.11.3 Establishment of design values for a specific product using prototype testing
5.11.3.1 General
When the design resistance Rd, for a specific product is established by prototype testing of that
product the following conditions shall be satisfied:
a) the minimum number of tests shall be 3;
b) the design value Rd shall satisfy:
Rd ≤ (Rmin. /kt)
where
Rmin. is the minimum value of the test results;
kt is the sampling factor as given in table 11.
NOTE The condition of the product under test should be the same as the condition of the product in use.
Table 11 — Sampling factor kt
1 2 3 4 5 6 7
Number of
test units
Coefficient of variation of structural characteristics
ksc
5 % 10 % 15 % 20 % 25 % 30 %
3 1,15 1,33 1,56 1,83 2,16 2,56
4 1,15 1,30 1,50 1,74 2,03 2,37
5 1,13 1,28 1,46 1,67 1,93 2,23
10 1,10 1,21 1,34 1,49 1,66 1,85
100 1,00 1,00 1,00 1,00 1,00 1,00
5.11.3.2 Interpolation of values obtained by prototype testing
When prototype testing is conducted for a range of a specific parameter (for example span), to
establish design values for a specific product in accordance with 5.11.3.1, it is permissible to
interpolate the obtained results for that parameter provided that there is no change in structural
behaviour (for example no change in collapse mode) within the interpolating range.
No extrapolation of test values is permitted.
5.12 Construction of the steel frame
5.12.1 Introduction
Buildings can be highly vulnerable during construction. An incomplete building is still required to be
safe for the people on site. The actions that need to be taken depend on the method of
construction.

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5.12.2 Factors to be considered during construction
The following factors shall be considered:
a) The partially complete structure may be subjected to a variety of loadings (see 5.3.4).
b) Regulatory safety requirements for workers in accordance with the relevant national legislation
(see foreword).
c) Provision of scaffolding and barriers, particularly those that rely on the building frame for support.
d) Temporary bracing and tie-down during the installation of permanent bracing and tie-down.
Particular care should be taken to provide adequate temporary bracing for the lower storey of
multi-storey construction where racking loads are significantly higher than those in single storey
buildings.
5.13 Tolerances
5.13.1 Manufacturing and assembly tolerances
5.13.1.1 Sections
The tolerances for cold-formed sections shall be determined such that the relevant actual sectional
properties differ by not more than ± 5 % from the design section properties.
5.13.1.2 Length
The length of a component shall not deviate from its specified length by more than ± 2 mm.
5.13.1.3 Straightness
A component that is specified to be straight, shall not deviate about any axis from a straight line
drawn between the end points by more than L/1000 or 6,0 mm, whichever is less.
5.13.1.4 Assembly
Assembled wall panels shall each not deviate from the specified dimension by more than:
Length: +2, −4 mm;
Height: ± 2 mm.
The height of assembled roof trusses may not deviate by more than ± 10 mm from the specified
dimension.
5.13.2 Installation tolerances
5.13.2.1 Attachment to supporting structure
For load-bearing walls (including shear panels), gaps between the bottom plate and the concrete
slab greater than 3 mm shall be packed with load-bearing shims under each stud. For non-load-
bearing walls, gaps greater than 3 mm shall be packed with load-bearing shims or grouted at jamb
studs and points where the bottom plate is fastened to the slab. Where the gap under the bottom
plate exceeds 10 mm the space between the bottom plate and the slab shall be filled with grout
after installation of the shims.
For the attachment of floor joists, bearers, trusses and rafters to walls, where the gap exceeds
3 mm, the gap shall be packed with load-bearing shims.

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5.13.2.2 Walls
5.13.2.2.1 General
The following tolerances are applicable to all vertical members including walls, posts, and stumps.
5.13.2.2.2 Position
Walls shall be positioned within 5 mm from their specified position.
5.13.2.2.3 Plumb
Walls and studs shall not deviate from the vertical by more than h/600 or 3 mm, whichever is
greater (see figure 21).
Figure 21 — Plumb of walls
5.13.2.2.4 Straightness
Walls, specified as straight, shall not deviate from a straight line by more than 5 mm over a
3 m length as shown in figure 22. Where wall panels join to form a continuous wall, the critical face
or faces of the panel may not deviate by more than ± 2 mm at the joint.
5mmmax.
3,0 m
Drg.740sb
Figure 22 — Straightness of walls

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5.13.2.2.5 Flatness of walls for installation of linings
The flatness of an individual wall that is to be lined shall be such that when a 1,8 m long straight
edge is placed parallel to the wall face, the maximum deviation from the straight edge does not
exceed 3 mm over 90 % of the area, and does not exceed 4 mm over the remaining area.
5.13.2.3 Trusses, rafters, ceiling joists and floor members
5.13.2.3.1 Position
Trusses, rafters, ceiling joists and floor members shall be positioned within 20 mm from their
specified position.
5.13.2.3.2 Straightness
Trusses, rafters, ceiling joists and floor members shall be installed so that they will not deviate from
a straight line by more than L/500 where L is the length of the member (see figure 23).
The difference in the level of points on adjacent members that are intended to be on the same level
shall not exceed 1/150 of the spacing of the members or 6 mm, whichever is less.
L = length of member
Figure 23 — Straightness of members
5.13.2.3.3 Plumb
Out of plumb at any point along the length of the truss from top to bottom, shall not exceed h/100
unless the trusses are specifically designed to be installed out of plumb (see figure 24).
5.13.2.3.4 Floor surface
The flatness of the floor surface shall be within ± 10 mm over the entire room, but not exceeding
± 5 mm over any 3 m length, unless specifically designed with a slope. Abutting floors between
rooms shall be aligned, unless specifically designed otherwise.

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Figure 24 — Plumbness of trusses
5.13.2.4 Vertical alignment of members
When members such as joists, rafter trusses and structural wall studs (above or below a wall plate)
are designed to be vertically aligned, the centre lines of the members shall not be more than 20 mm
apart, as shown in figure 25.
Figure 25 — Vertical alignment of members

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5.14 Durability and corrosion
5.14.1 Steel structure
Steel covered by wall or roof cladding, or surrounded by subfloor walling, and not within 500 m of
the sea, as well as steel that is not covered by cladding or surrounded by subfloor walling, and not
within 10 km of the sea or within a heavy industrial area, shall be continuous hot-dip galvanized
sheeting with minimum coating class Z200, or a coating with corrosion resistance at least equivalent
to 100 g/m2
galvanising, per side. An appropriate higher level of corrosion protection is required for
steel structures located closer to the sea or within heavy industrially polluted areas.
Wherever galvanized steel has been welded or cut by flame, the affected areas shall be painted
with a zinc-rich paint having at least 85 % of zinc in the dry film.
5.14.2 Fasteners
5.14.2.1 The minimum specification for corrosion protection of fasteners is supplied in table 12.
Table 12 — Corrosion protection requirements for fasteners
1 2 3 4 5
Application Location in building
Ease of
access
a Atmosphere
b
Coating
class
c
min.
Steel wall frames
Inside building envelope
Difficult Inland C2
Difficult Aggressive C2
Outside building envelope
Easy Inland C2
Easy Aggressive C3
Trusses
Ventilated roof cavity
Difficult Inland C2
Unventilated roof cavity
Difficult Inland C2
Wall frame anchors Inside building envelope
Difficult Inland C2
External cladding Outside building envelope
Easy Inland C2
Easy Aggressive C3
Internal lining, ceilings
'Wet rooms'
Easy Internal – Regular
condensation C2
All other rooms Easy Internal – Dry C1
Roofing Outside building envelope
Easy Inland C2
d
Easy Aggressive C3
d
a
For inspection and maintenance.
b
'Aggressive': Marine environment (500 m to 10 km from the sea), or industrially polluted
atmospheres. 'Inland': All other environments.
c
Coating class defines the corrosion resistance requirements. (See 5.14.2.2.)
d
Subject to the requirements of SANS 1273.

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5.14.2.2 Test for compliance with coating class requirements: Screws shall be driven into a
galvanized sheet of at least 1,5 mm thickness, then removed and mounted on an inert material for
testing. The significant surface (i.e. head and un-driven shank) shall be evaluated. Salt fog tests
shall be made in accordance with SANS 7253, with an additional 240 h of UV exposure before this
for fasteners with organic coatings. The UV requirements shall be in accordance with ISO 11997-2,
as follows: Amdt 1
a) Lamps and wavelength: UVB 313/280 nm.
b) Cycle: 4 h UV/60 °C, 4 h condensation/50 °C.
For C1 after exposure for 72 h, C2 after 240 h, and C3 after 1 000 h, no more than 5 % of the
significant exposed surface shall show red rust and there shall be no blistering of the coating.
5.14.2.3 Fasteners of the coating types in table 13 comply with the test requirements for the
respective coating classes.
Table 13 — Corrosion protection requirements for fasteners
1 2 3
Coating class Coating type
Minimum coating
thickness
μm
C1 Electroplated zinc 4
C2
Electroplated zinc 12
Mechanically plated zinc
a
17
Mechanically plated tin-zinc (≥ 20 % Sn, bal Zn)
a
12
C3
Electroplated zinc 30
Mechanically plated zinc
a
40
Mechanically plated tin-zinc (≥ 20 % Sn, bal Zn)
a
25
Hot-dip galvanized 30
a
The porosity of mechanically plated coatings requires microscopic examination of a
cross section through the coating, at 500 × magnification. It shall be carried out over a
suitable flat surface on the head of the fastener. No continuous through thickness
porosity shall be evident.
5.14.2.4 Fasteners not inside the building envelope and not washed by rain (for example under
overhangs) in marine and industrial environments, require additional protection against corrosion,
such as organic coatings.
5.14.2.5 Fasteners or the packaging (or both) should be acceptably marked to show compliance.
5.14.2.6 Manufacturers of rivets should provide evidence that rivets, once installed, have durability
required by the design, i.e. life expectancy equivalent to that of the materials being connected and
compatibility with those materials.
5.15 Support of wall cupboards and fittings
Noggings or other structural elements of sufficient strength shall be provided as required to support
fittings such as kitchen cupboards or sanitary fittings and taps.

SANS 517:2013
Edition 1.2
57
5.16 Earthing
The steel frame shall be properly electrically earthed to comply with SANS 10142-1.
6 Walls, roofs and suspended floors
6.1 Scope
The requirements of this section cover the cladding, insulation, waterproofing and other materials
attached to or installed between the elements of the steel frame. Windows, doors and other
installations for ventilation such as natural lighting are excluded. Specific information is provided for
domestic dwellings. All buildings shall be designed to meet the requirements of the relevant national
legislation (see foreword) for such buildings, and any additional applicable requirements.
6.2 General requirements
6.2.1 Damp and weatherproofing
Roofs, floors and external walls shall prevent the ingress of moisture from outside the building
envelope that can affect the health or comfort of occupants.
6.2.2 Durability
The building shall, with appropriate maintenance, be able to survive for its design life.
6.2.3 Energy efficiency
6.2.3.1 General
The building shall facilitate, through its thermal performance, the efficient use of energy for artificial
heating or cooling, while providing an acceptable indoor environment for its occupants or the
processes conducted in the building.
A number of factors impact on the thermal efficiency of a building, such as roof colour, orientation of
the building, area and type of glazing, shading for windows, sealing against uncontrolled airflow and
insulation of walls, ceilings and floors (see SANS 204). Only the limitation of uncontrolled airflow
and insulation are addressed in this standard. Amdt 2
South Africa has been divided into six climate zones (see figure 26). The recommended R-values
below are based on the climatic conditions in each zone.
6.2.3.2 External walls
In order to meet the requirement of 6.2.3.1, the external walls of a domestic dwelling shall meet the
thermal insulation requirements in table 14. Where a garage is attached to a domestic dwelling,
either the outer wall of the garage, or the wall separating the garage from the domestic dwelling,
shall meet the requirements in table 14.

SANS 517:2013
Edition 1.2
58
Amdt 1; amdt 2
Figure 26 — Map of climate zones in South Africa
Table 14 — Minimum required R-value (m2
·K/W)) of thermal
insulation for external walls of domestic dwellings
1 2 3
Building
Climate zone
1, 4 or 6 2, 3 or 5
Required R-value
(m
2
·K/W)
Category 1 buildings 1,32 1,14
All other buildings 2,20 1,90
NOTE The climate zones for South Africa are
defined in figure 26.
Amdt 1

SANS 517 Mr Venish Dewrajh

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