Details glass design for horizontal floors and stairs and overhead glazing.

1. Glass Horizontal
and Overhead
Competent Person(Glazing)

2. Glass Horizontal
and Overhead
Glass Floors and Stairs
Roof Lights and Canopies

21. 1. Legal Framework
2. Design Principles
3. Calculation and Testing
Glass Horizontal
and Overhead

22. 1.Legal Framework
2. Design Guidelines
3. Calculation and Testing
Glass Horizontal
and Overhead

23. Regulation - PART B - STRUCTURAL DESIGN
B1 DESIGN REQUIREMENT
(1) Any building and any structural element or component
thereof shall be designed to provide strength, stability,
serviceability and durability under all actions which can
reasonably be expected to occur in accordance with accepted
principles of structural design, and so that it will not impair the
integrity of any other building or property.
(2) Any such building shall be so designed that in the event of
accidental overloading the structural system will not suffer
disastrous or progressive collapse which is disproportionate to
the original cause.
(3) The requirements of sub-regulations (1) and (2) shall be
deemed to be satisfied where such building is designed in
accordance with SANS 10400-B.

24. 4.2.1.2 The representative permanent, imposed and seismic
loads and impact sources applied to the structure and
structural elements shall be in accordance with the
requirements of SANS 10160.
SANS 10400 The application of the
National Building Regulations
Part B: Structural design
4.2.1.1 The design working life of a building other than a
category 1 building shall be not less than 30 years in respect of
the structural system and non-accessible components, and 15
years for repairable or replaceable components and materials,
such as claddings, roofing materials, exterior trims, and
integrated components, such as windows and doors.

25. PART N - GLAZING
N1 TYPE AND FIXING OF GLAZING
(1) Any material used in the glazing of any building shall be of a secure and
durable type and shall be fixed in an manner and position that will ensure
that it will -
(a) safely sustain any wind actions which can reasonably be expected;
(b) not allow penetration of water to the interior of the building; and
(c) be apparent, in the case of clear glazing, to any person approaching such
glazing.
(2) Glass, plastics and organic coated glass shall be selected in order to
provide, in the case of human impact, a degree of safety appropriate in
relation to -
(a) the position of the glazed area; and
(b) the number and likely behaviour pattern of persons expected to be in
close proximity to such glazed area.
(3) The requirements of sub-regulations (1) and (2) shall be deemed to be
satisfied where the glazing material is selected, fixed and marked in
accordance with SANS 10400-N.

26. SANS 10400 N - Glazing
4.2.3 The thickness of panes of glass and flat solid
polycarbonate sheeting, other than in lifts, shall
a) be not less than that given in tables 1 to 6, or
b) be determined by a competent person (glazing) in
accordance with the requirements of SANS 10137, and be
based on wind loads determined in accordance with the
requirements of SANS 10400-B.

27. Table 1 — Dimensions for vertical glass supported by
a frame on all sides in external walls in buildings
where the height measured from the ground to the top
of such wall does not exceed 10 m

28. SANS 10137
1 Scope
This standard covers the design and installation of glazing
and glazing materials used in buildings and is for
applications described in SANS 10400-N, and for use by a
competent person (glazing).
NOTE 1 Compliance with this standard does not necessarily grant
exemption from the need for compliance with the relevant national
legislation (see foreword).
NOTE 2 The design methods described in this standard may represent
only one of many methods of determining glass thickness and strength
requirements for a given situation. A competent person (glazing) may
use any method of calculation they deem fit for purpose provided such
method represents good engineering design practice, acceptable safety
factors and deflections, and can be backed up by reference to
reference material or test data.

29. SANS 10137:2011 Edition 4
6.6 Glass floors
6.6.2 Imposed loads (for example, distributed
load and point load) shall be in accordance
with SANS 10160-2 which determines that a
glass floor for a building classified in
accordance with SANS 10400-A, as residential,
will not necessarily use the same design floor
load as an office.
Design shall take into account the post
fracture behaviour of the glass and that the
design stress for glass declines with an
increase in the time that the load is applied
(see table 5)

30. SANS 10400 N - Glazing
4.4 Safety glazing
4.4.1 The performance of safety glazing material shall be
in accordance with the requirements of SANS 1263-1 and
the individual panes of safety glazing material shall be
permanently marked by the installer in such a manner that
the markings are visible after installation.
h) glazing applications are sloped or horizontal;

31. SANS 204 Energy Efficiency in Buildings

32. 1. Legal Framework
2.Design Principles
3. Calculation and Testing
Glass Horizontal
and Overhead

33. 1. Glass is a brittle material.
2. It has perfectly elastic behaviour until it is overloaded
and it snaps.
3. Normally the overload is on a defect – a scratch or chip
that concentrates the force – so the shape or surface
treatment affects the strength.
1. Sandblasting
2. Frit pattern
Design Principles

35. 4. It does not fatigue like metals - Fatigue depends upon
movement of defects in a metal's crystal structure
called dislocations. Glass doesn't have a crystal
structure or dislocations, so it won't fatigue in the same
way. Glass can be loaded an infinite number of times
at stresses below the yield point without any reduction
in strength.
5. Glass suffers from static fatigue – constant, or static
loading, over time reduces the design strength.
Design Principles

36. Load Duration Factors adapted from
ASTM E1300-02
Duration Factor
3 s 1.00
10 s 0.93
1 min 0.83
10 min 0.72
60 min 0.64
12 h 0.55
24 h 0.53
1 week 0.47
1 month 0.43
1 year 0.36
Beyond 1 year 0.31

37. 6. Safety glazing to be used that does not fall or if it falls
is safe.
7. People generally do not like to walk on glass. Do not
let it deflect too much.
Design Principles

38. Glass Floors.
1. Small deflection – much less than the
glass thickness.
2. Use standard design formulas like Roark.
3. Four edge support and two edge.
4. Design loads from SANS 10160 Part 2.
1. Point load plus self weight
2. Distributed load plus self weight
5. If the bottom leaf breaks the rest of the
construction must take the load

39. 5.3 Ultimate limit states
5.3.1 Ultimate limit states relate to the following:
a) the safety of people; and
b) the safety of the structure.
5.4 Serviceability limit states
5.4.1 Serviceability limit states apply to the following
requirements for the structure under normal use:
a) the functioning of the structure or structural members;
b) the acceptability of the structure by users in terms of
perceived safety and wellbeing; (for example deflection) and
c) the appearance of the structure. (for example distortion)
3.1.24
serviceability limit states
states that correspond to conditions beyond which specified
service requirements for a structure or structural member are
no longer met
3.1.26
ultimate limit state
state associated with collapse or with other similar forms of
structural failure

41. 9 Imposed loads on buildings
9.1 Actions
9.1.1 Imposed loads on buildings arise from occupancies such as
a) normal use by persons,(impact loads, point loads on floors and roofs)
b) furniture and movable objects (for example, moveable partitions, storage or
the contents of containers),
c) vehicles,
d) anticipated rare events, such as concentrations of persons or of furniture,
(point loads on roof lights due to maintenance and cleaning)
e) the moving or stacking of objects which may occur during reorganisation or
redecoration, and
f) storage and industrial use.
9.1.2 Imposed loads are modelled by uniformly distributed loads (wind load
and self weight), line loads or concentrated loads or combinations of these
loads.
9.1.3 For the determination of imposed loads, the floor and roof areas of the
building shall be subdivided into categories according to their use.
9.1.4 Heavy equipment (for example, in communal kitchens, radiology rooms
or boiler rooms) is not covered in this part of SANS 10160 and the appropriate
floor loads shall be established in accordance with the principles given in SANS
10160-1.

45. 9.3 Characteristic values of imposed loads
9.3.1 Residential, social, commercial and administration areas
9.3.1.1 Areas in residential, social, commercial and administration buildings shall be
divided into categories according to their specific uses as shown in table 1.
9.3.1.2 Independent of this classification of areas, dynamic effects shall be considered
where it is anticipated that their occupancy will cause significant dynamic effects (see
5.2.3 and 5.2.5).
9.3.1.3 The loaded areas for categories, as specified in table 1, shall be designed by
using characteristic values, qk (uniformly distributed load) and Qk (concentrated load). The
characteristic load, qk, is intended for the determination of general effects and Qk, for the
determination of local effects.
9.3.1.4 The characteristic values for, qk and Qk, are minimum values and shall be
increased in the design where necessary.
9.3.1.5 The loads, qk and Qk, shall not be applied simultaneously.
9.3.1.6 For concentrated loads which arise from storage racks or from lifting equipment,
Qk, shall be determined for the individual case (see 9.3.2).
9.3.1.7 The concentrated load shall be considered to act at any point on the floor,
balcony or stairs.
9.3.1.8 Where floors are subject to multiple use, they shall be designed for the most
unfavourable category of loading which produces the highest effects of actions (for
example, forces or deflection) in the member under consideration.

46. 1. Design to deflection limit
2. Distributed load plus self weight/thickness.
SANS 10160 Part 2.

47. Distributed
load
Stress
MPa
Point
Load
Stress
MPa
Layered
1.5 0.71 1.5 2.73 4.71
2.0 0.87 1.5 2.73 4.71
3.0 1.19 1.5 2.73 4.71
4.0 1.51 3.0 5.44 9.44 (7.70)
Includes self weight.
1 x 1 m simply supported 3 x 10 mm

48. Distributed
load
Stress
MPa
Point
Load
Stress
MPa
Layered
2.5 0.71 4.5 8.17 14.15
3.0 1.19 4.5 8.17 14.15
3.0 1.19 5.0 9.07 15.73
5.0 1.83
Includes self weight.
1 x 1 m simply supported 3 x 10 mm

50. Glass Roofs.
1. Large deflection – much more than the
glass thickness.
2. Non-linear behaviour.
3. Generation of web stresses

52. Glass Roofs.
1. Large deflection – much more than the glass
thickness.
2. Non Linear behaviour.
3. Generation of web stresses
4. Use standard design formulas like Roark
will give a conservative design.
5. Four edge support and two edge.
6. Design loads from SANS 10160 Part 2.
1. Point load
2. Distributed load plus self weight.

54. Distributed
load
Stress
MPa
Point
Load
Stress
MPa
Layered
0.5 5.1 1.0 45.4 64
0.75 7.1 1.0 45.4 64
2.0 17.1 2.0 90.7 128 (26mm)
Suggests 10.38 minimum
Includes self weight.
1 x 1 m simply supported 6.38 mm

55. Australian Code AS 1288
6.5 SELECTION OF OVERHEAD GLASS
6.5.2 Permanent, imposed and other actions
The design pressure resulting from the weight of the glass
(dead loads) shall be determined from Table 6.1. This
design pressure shall be used in Clause 6.5.5 to
determine the ultimate limit state design pressure for the
combined loads.
6.5.3 Wind actions – use wind load charts.

56. 6 mm glass

57. 6.5.4 Live Load (concentrated point load) application. Sloped
overhead glazing with a live point load applied is deemed to
comply with this Section if the glass is selected in accordance with
Tables 6.3 to 6.6. When using Tables 6.2 to 6.5, the following
limitations apply:
(a) The point load shall be applied as a uniformly distributed load
over a circular area of 0.01 m2.
(b) Glazed panels inclined at less than 30° to the horizontal shall
be capable of supporting the actions incidental to maintenance
(1.8 kN in street awnings or 1.1 kN in other roofs).
(c) Glazed panels, which are not in street awnings and inclined at
30° or more to the horizontal, shall be protected by boards or
ladders laid over the glazed panels to support the actions
incidental to maintenance (0.5 kN live load).
(d) For a glazed panel supported on all edges, the point loading
shall be applied at the centre.
(e) For free glazing edges, the point load shall be applied adjacent
to the centre of the free edge.

58. 6.5.5 Combined loads (dead, wind)
The combined design loads for sloped overhead glazing
shall be calculated as follows:
Case 1 Dead (maximum) + wind (downward)
Case 2 Dead (minimum) + wind (upward)

62. Example:
Horizontal Roof Light with a wind load perpendicular
vertically downward on the glass supplied by the engineer of
600 Pa and vertically upward of 1200 Pa.
Panel size is 1200 x 1200 mm.
Aussie Code:
1. Take weight of the glass and convert to Pa.
a. 6.38 – 6 x 2.5 x 9.81 = 147 Pa
b. 8.38 – 8 x 2.5 x 9.81 = 196 Pa
c. 10.38 – 10 x 2.5 x 9.81 = 245 Pa
2. Factor wind load up
a. 6.38 – 6 x 2.5 x 9.81 = 147 – 1200 = - 1053 Pa
b. 8.38 – 8 x 2.5 x 9.81 = 196 – 1200 = -1004 Pa
c. 10.38 – 10 x 2.5 x 9.81 = 245 – 1200 = - 954 Pa
3. Factor wind load down
a. 6.38 – 6 x 2.5 x 9.81 = 147 + 600 = 747 Pa
b. 8.38 – 8 x 2.5 x 9.81 = 196 + 600 = 796 Pa
c. 10.38 – 10 x 2.5 x 9.81 = 245 +600 = 845 Pa

63. Laminated
1200 x 1200 = 1.44 m2
6.38 is Ok to 3000 Pa

64. Example:
Horizontal Roof Light with a wind load perpendicular
vertically downward on the glass supplied by the engineer of
600 Pa and vertically upward of 1200 Pa.
Panel size is 1200 x 1200 mm - AR = 1
Aussie Code:
4. Take point load for horizontal laminated annealed glass:
Gives 12.38 mm - or 8.38 mm if slope is more than 30o
Using Roark gives 10.38 mm using 1kN and 8.38 @ 0.5kN
– 1.1kN gives 12.38

65. 1. Legal Framework
2. Design Guidelines
3.Testing
Glass Horizontal
and Overhead

87. 4.2 General pre-requisites
The general pre-requisites for the application of
SANS10160 are as follows:
a) the choice of the structural system and the design of
the structure shall be made by a competent person;
b) execution shall be carried out by personnel having the
appropriate skills and experience;
c) adequate supervision and quality control shall be
provided during the execution of the work, namely, in the
design offices, factories, plants, and on site;
d) the construction materials and products shall be in
accordance with the appropriate materials based
structural design standards (see 4.1).
e) the structure shall be adequately maintained; and
f) the structure shall be used in accordance with the
design assumptions.

88. 5
3
6
Glass Floor – Annealed Glass Supported on
All Four Edges
Section of Elevation
1
2
1. 30mm laminated safety glass marked
with SABS 1263 Part 1 manufactured
from three 10 mm thick (nominal) glass
and PVB interlayers with flat ground and
arrissed edge work. Non slip surface
finish to architect specification.
Translucent interlayer.
2. Structural silicone sealant DC 895 or
equivalent approved to meet 1MPa
tensile. Installed to comply with
manufacturers warranty requirements.
Minimum size 6 x 12 mm. Site application
not allowed.
3. Preformed silicone setting blocks 80
Shore hardness compatible with
structural seal, glass interlayer and
supporting structure.
4. Fastenings to superstructure, M6 for
location only, four per sub frame.
5. 316/304 Grade Stainless Steel non-
supporting framework resting on
superstructure, 40 x 40 x 4 mm.
6. Weather seal of silicone compatible with
glass interlayer, silicone setting blocks
and supporting structure.
• Glass to be marked in accordance with
SANS 1263 Part 1.
• Not to scale – arrangement only.
• Measures to be taken to prevent galvanic
corrosion
• Floor glass mock up to be design load
tested prior to approval