SCOPE

  • The scope of this guide is limited to the behaviour of safety glass when subjected to various kinds of human impact, precautions against risk of fall and falling glass. Conditions outside of ‘human impact’ are not in the purview of this document.
  • This guide does not assume that the safety glass used in accordance to this document will not be broken under all human impact conditions, rather: a) It will not be broken under most likely forms of human impact and, b) Even if it breaks the likelihood of cutting or piercing injuries will be minimized by virtue of the protection given to the glass, or by the limited size or increased thickness, or by the fracture characteristics of the glass.
  • Further this guide does not deal with the safety and security of people or goods in relation to risks of:
    a) Vandalism, riots, burglary or break in protection,
    b) Fire arm protection,
    c) Protection from explosion (terrorist attack),
    d) Natural disasters like Earthquakes, Hurricane, Fire etc.,
    e) Plastic glazing, safety and security glazing etc.
  • These areas are to be discussed in other subsequent documents.
  • In some circumstances the requirements of other standards can exceed the requirements of this guideline and, in such cases the higher requirement shall become applicable.

Safety Glass

Glazing material constructed, treated, or combined with other materials so as to reduce, in comparison with ordinary sheet, float or plate glass, the likelihood of injury to persons by objects from exterior sources or by these safety glasses when they may be cracked or broken.

The following are three products in the scope of this document that may be used in safety glazing provided they meet the Bureau of Indian Standards (BIS) conditions and are marked accordingly. Also they must meet the requirements of traceability.

  • Toughened (Tempered) Safety Glass: A single piece of specially heat-treated or chemically treated glass, with a stress pattern such that the piece when fractured reduces to numerous granular fragments, with no large jagged edges.
  • Laminated Safety Glass: Two or more pieces of glass held together by an interleaving layer or layers of plastic materials. The laminated glass will crack and break under sufficient impact, but the pieces of glass tend to adhere to the plastic and do not fly. If a hole is produced, the edges are likely to be less jagged than that would be the case with ordinary glass.
  • Safety Organic-Coated Glass: A glazing material consisting of a piece of glass coated and permanently bonded on one or both sides with a continuous polymeric coating, sheet or film, which meets the test requirements of the safety glazing standards.
  • These glasses can be of any other types which includes:- Clear, Tinted, Coated, frosted, decorative or mirror.
  • PRECAUTIONS
    • All heat-treated glasses are not safety glasses and all laminated, toughened and safety organic coated glasses are not safety glasses. Heat strengthened glasses and annealed glasses are not classified as safety glasses unless laminated to meet the test specified for safety glass in clause 6.0 of this document. Glass laminated with other than polyvinyl butyral (PVB) may not classify the requirement of safety glass. Only glass that meets the test criteria as defined in this document is expected to qualify as safety glass.
    • All window glass films are not safety films unless these are of the required minimum thickness and type, and pass the test standards defined in clause 6.0 of this document.
    • The use of this document must also be in conformity with all other relevent codes on fire, structural stability, natural disasters, safety and security etc.

Critical Locations

DEFINITION

Critical locations are parts of a building most likely to be subject to accidental human impact.

CLASSIFICATION OF CRITICAL LOCATIONS

  • Where any glazing is within 1.5 metre above the floor level of a building, it is considered likely to be subjected to human impact and hence, shall comply with the human impact safety requirements of this guide. Safety glazing material should also be used:
    • Where there is danger of falling infill glass materials from overhead glazing,
    • The danger of falling due to a change in floor level,
    • In case of balustrades, stairs and floors.
  • Accident statistics show that the glazing in some locations in buildings are more vulnerable to human impact than in others. These critical locations, some of which have been shown in Table A, include the following:
    • In-and-around doors, low windows,
    • Panels mistaken for a doorway or opening,
    • Panels at low levels in walls and partitions,
    • Bathrooms,
    • Building associated with special activities, e.g. gymnasia, enclosed swimming pools etc.,
    • Schools and child care facilities,
    • Nursing Homes and aged care facilities.
  • Precautions should be taken to reduce the injuries that can result from glass breakage by:
  • Selecting glass of a suitable type, thickness and size,
  • Enhancing a person’s awareness of the presence of glass by making glass visible (manifestation),
  • Minimizing manual handling of large pieces of glass during installation.
  • Based on the above facts and to avoid confusion regarding the type of the glass for a particular location as mentioned above, this guide has given details on the basis of five cases found in common accidental cases.

1AS 1288-2006, Glass in building – Selection and Installation

Guidelines on use of Glass in Buildings – Part A : Human Safety

 

Type of glass Any glass* Safety glass Safety glass Laminated safety glass Laminated safety glass
Examples Please refer to note 4 *Residual protection is the protection provided to avoid the impact of human being to glass. It is provided on the side of glass where there are chances of Human impact. It can be achieved by providing protection in form of a sill structure or transom, chair rail or a grill inside. Also please refer to recommendations against falling of glass. *Safety glass is not mandatory – Doors
– Side Panels
– Curtain Walls
– Glazed Area
– Doors in Bathroom,
a) Fully Framed
b) Partially Framed
c) Frameless
– Façade
– Windows
– Internal Partitions
and Doors – External Facade and Doors on ground floor, above floor with terraces outside.
– Curtain Walls
– Façade
– Spandrels
– High Activity
Area – High Risk Area
– Roof (Skylight Roof)
– Ceilings
– Bus Shelters
– Floors
– Stairs
– Sloped Facade For definition of sloped glazing please refer to annexure 4
– Balustrades
– Balcony
– Handrail
– Lifts

For sketches of examples refer annexure 1

NOTES TO TABLE A

Note 1: ‘Hf ‘corresponds to falling height in case of change in level and ‘Hs’ corresponds to the sill height.

Note 2: For definitions and explanation of terms see annexure 4.

Note 3: In case of mirror glazing, it should confirm to the requirements of other safety glasses unless it is fully backed by a solid material.

Note 4: If the smaller dimension of the pane is 250 mm or less and its area is 0.5 sqm or less, glass not conforming to safety glass requirements may be used, provided that its nominal thickness is not less than 6 mm. (applicable to vertical glazing)

Note 5: Toughened or laminated safety glass or safety organic coated glass should meet respective test requirements as mentioned in clause 6.0 of this document to qualify as safety glazing.

Note 6: The effective Toughened safety glass thickness and/or Laminated safety glass and/or Safety organic coated glass configuration shall be determined case by case with regard to:

  • Other solicitations (wind load, snow load, dead load, and human load; refer para 3.3)
  • The overall dimension (length / width, or surface)
  • The aspect ratio of the glass (length / width)
  • The glazing fixing type (framing, bolted system, structural system etc.) Refer annexure 2 & 3.

Note 7: Precautions against chances of injuries due to broken glass falling on people:

  • Broken annealed glass falling on people can cause grievous or even fatal injuries; hence it is recommended to use safety glass in locations other than defined in case 1 where the risk of people getting hurt by falling glass is high.
  • Toughened (tempered) glass has a safe breakage pattern, as it breaks and disintegrates into small and relatively harmless particles. However thick toughened glass particles may stay interlocked and fall as lumps of these multiple particles and can cause a minor or medium injury mainly due to the weight of the cluster.
  • Laminated safety glass will generally not fall out of fixing. However, where laminated glass with both glasses toughened, used for horizontal or sloped glazing is used, in case of failure of both toughened glasses, it may crumple as a blanket and fall out of fixing. This factor needs to be considered while designing horizontal and sloped glazing.
  • Safety organic coated glass if broken will be difficult to penetrate provided that the covering is applied in accordance with the manufacturers’ recommendations.
  • Any broken glass in any glazing should be removed immediately on breakage.
  • Strength of the glazing system should be such that it has the ability to hold glass in place and prevent it from falling out as a whole.

Note 8: For inclusion of glass in furnitures the following standards may be referred:

  • BS 7499:1991 – Specification for inclusion of glass in the construction of furniture, other than tables or trolleys, including cabinets, shelving systems and wall hung or free standing mirrors.
  • BS 7376:1990 – Specification for inclusion of glass in the construction of tables or trolleys.
  • IS 7760:1985 – Specification for steel glassfront cabinet.
  • BS EN 1727:1998 – Domestic furniture, storage furniture, safety requirements and test methods.
  • BS EN 1153: 1996 – Kitchen furniture, safety requirements and test methods for builtin and free standing kitchen cabinets and work tops.

Note 9: In case of external laminated glass facades, openable portions have to be left at regular distances for fire fighting and smoke exhaust.

Note10: If Insulating Glass Unit (IGU) is used in situations mentioned in this guide then any one of the following will apply:

  • If IGU is installed in areas subjected to human impact on either side then both the panes of the unit shall meet the requirements of this guide.
  • In situations where access is restricted to one side of the unit, then only the accessible side should meet the requirements of this guide.

LIST OF STANDARDS TO BE REFERRED FOR PROPER SELECTION

As mentioned in note 6, page 13, various factors like wind pressure, glass thickness, human load, aspect ratio, glazing type etc. need to be considered before selecting the safety glass. Below are a number of standards available, which can be referred to correctly select the safety glass.

  • IS : 2553 (Part 1) – 1990 Safety Glass – Specification
  • IS : 2835 – 1987 – Specification for Flat Transparent Sheet Glass (third revision)
  • IS : 875 – Codes for the Wind Loads
  • BS : 952 – For Nominal Thickness of Glass
  • AS : 1288 – 2006 – Glass in Buildings – Selection and Installation
  • BS : 6262, Part 4 – 1994 – Code of Practice for Glazing for Buildings – Safety related to Human Impact
  • BS : EN 12600 – 2002 – Glass in Buildings – Pendulum Test – Impact test method and classification for flat glass
  • ANSI Z 97.1 – 1984 (R1994) – Safety Glazing Materials used in Buildings, Safety Performance Specifications and Methods or Tests

Application / Installation

GENERAL SAFETY CONSIDERATION

  • Many human impact injuries are due to failure to take reasonable safety precautions. Some materials, such as glass, may break under impact and cause injury. Most people are aware of this and treat such materials with due care. However a person’s ability to perceive this potential risk and to cope with it can vary. Safety standards are therefore based on a number of factors including the assumption of a reasonable level of awareness and behaviour and also suitable product design and choice of materials.
  • Accident statistics show that glazing in some locations in buildings is more vulnerable to human impact than in others. These critical locations are:
    • In-and-around doors (particularly side panels may be mistaken for doors),
    • At low levels in walls and partitions.
  • The designer, or specifier, should take precautions to reduce the risk of injuries from accidental human impact in these locations by:
    • Selecting glass of a suitable type, thickness and size, primarily with reference to impact behaviour and safety characteristics as established by testing in accordance with this guide,
    • Providing mechanical protection to glass in critical locations,
    • Enhancing a person’s awareness of the presence of glass by incorporating manifestation as mentioned in clause
  • Glass in locations other than critical locations is not likely to be subject to human impact and consequently not likely to cause injury.
  • DESIGN CONSIDERATION
    • The principal design considerations to be taken into account by the designer, or specifier, when selecting glass should be:
      • The properties of materials, in particular their breakage characteristics;
      • Type of glass systems supporting the glass.
      • The type of the building and its use, in particular the number and likely behaviour of the people expected to be in close proximity to the glass in critical locations;
      • Requirements for fire, security and wind loading.
      • Structural integrity, thermal breakage, energy efficiency and deflection, vision, acoustics and other consideration.
      • Impact of trolleys, carts, luggage etc. used have to be considered when required.
  • INSTALLATION OF GLASS
    • Design of the glazing system should be such that it has the ability to hold glass in place and prevent it from falling out as a whole.
    • For guidance on installation of glass following standards may be referred.
      • IS : 3548 – 1988 – Code of Practice for Glazing in Buildings
      • IS : 10439 – 1983 – Code of Practice for Patent Glazing
      • BS : 8213: Part 4: 1990 – Windows, Doors and Rooflights: Code of Practice for the Installation of Replacement Windows and Doorsets in Dwellings
      • BS : 6262: Part 6: 1997 – Code of Practice for Glazing for Buildings: Special Applications
      • BS : 8000: part 7: 1990 – Workmanship on Building sites – Code of Practice for Glazing
      • AS : 1288 – 2006; Section 8 and 9 – Glass in Buildings – Selection and Installation
      • BS : 5516-1:2004: Patent Glazing and Sloped Glazing for buildings – Code of practice for design and installation.
      • Glass Association of North America Installation Guide.
    • In case of installation of safety films at site, it should be verified that they are free from defects or imperfection, any foreign contaminants may be removed with industrial razors and neutral cleaning solutions. It should also be noted that in case the glass receives scratches or any defects while installation of safety films the glass should be removed or rejected.
  • MANIFESTATION
    • Presence of glass in a door, side panel or a panel capable of being mistaken for a doorway or opening, which are not made apparent by transoms, colonial bars, other components of glazing system, or other decorative treatment, such as being opaque, or patterned, the glass be marked to make it visi
    • Marking shall be in the form an opaque band not less than 20 mm in height and located so that the vertical distance from the floor level is not less than 700 mm from the upper edge of the band and not more than 1200 mm to the lower edge of the band.
    • The band shall be such that it is readily apparent and it can be achieved by contrasting the band with background or by increasing height of band. Safety glazing cannot be substituted by making the glass visible by marking.
    • A band or marking is not required where any one of the following applies:
      • Height of the glass is not greater than 1000 mm at any part,
      • The width of the glass is not greater than 500 mm at any part (this applies to overall panel assembly – not individual glass pieces in case of faceted glazing),
      • Within 750 mm of the floor there is no glass.
      • The glass is provided with at least one fixed glazing bar, firmly attached to the styles to locate and protect each face of the glass. At least one glazing bar shall be located with its upper edge not less than 500 mm and its bottom edge not more than 1000 mm above the floor level. The glazing bar shall have a face width not less than 40 mm ± 3 mm.
    • Alternatively patterns may be used as an acceptable form of marking provided it meets the other criteria set in this guideline.

Traceability of Safety Glass

All Safety glasses shall be procured from certified manufacturers and the product shall conform to relevant standards.

Either a label that cannot be removed and reused or a permanent mark on the glass surface shall mark all the panels of safety glass according to Bureau of Indian Standards (BIS).

Each lable must contain the ISI mark as prescribed by the BIS, manufacturers name, registered trademark or code of the manufacturer or supplier, type of safety glass material, the standard or guidelines to which the safety glass has been tested and the grade of test classification.

.

Safety Glass Test Requirement

If the glasses satisfy the relevant impact test performance requirements (or fragmentation test for toughened glass), in addition to all other appropriate tests to be carried out as listed in the table below, these materials can be classified as safety glass.

TABLE B

Test Laminated Safety Glass Toughened Safety Glass Safety Organic-coated Glass Standards to be referred
Impact / Resistance to shock
YES
YES
YES
AS: 2208 – 1996
BS EN: 12600 – 2002
BS 6206 : Part 4 – 1994
ANSI Z97.1 – 1984
16CFR Ch II (1-1-04 Edition)
JIS R 3206 – 1997
JIS R 3205 – 1997
DIN 52 337
IS 2553 (Part 1:1990)
Fragmentation
Yes
IS : 2553 (Part 1) – 1990
Boil
YES
IS : 2553 (Part 1) – 1990
Accelerated Weathering and Ageing Test
YES
AS: 2208 – 1996
ANSI Z97.1 – 1984
16CFR Ch II (1-1-04 Edition)
Fracture and Adhesion Test
Yes
Yes
IS : 2553 (Part 1) – 1990
Light Stability Test
Yes
Yes
IS : 2553 (Part 1) – 1990

In the above table ‘YES’ indicates test to be conducted.

Boil test for heat strengthened and toughened laminated glass can use laminates from ordinary annealed glass manufactured simultaneously.

DESCRIPTION OF TESTS REQUIRED TO CLASSIFY GLASS AS SAFETY GLASS

  • Determination of thickness test: This test determines the thickness of a glass. The glass is measured at specified locations with a vernier calliper or micrometer. IS : 2553 (Part 1) – 1990 may be referred for the test.
  • Impact test: This test determines the resistance of glass to impact by penetration method. The specimen is supported vertically in a steel frame and an impact shot bag is released from a pre-determined height to strike the specimen at the centre. The height is progressively increased until fracture occurs. AS: 2208 – 1996; BS EN: 12600 – 2002; BS 6206 : Part 4 – 1995; ANSI Z97.1 – 1984; 16CFR Ch II (1-1-04 Edition); JIS R 3206 – 1997; JIS R 3205 – 1997, DIN 52 337, standards may be referred for the test.
  • Resistance to shock test: In this test the toughened safety glass is given a sudden shock with a smooth surface steel ball of 63.5 mm in diameter from a height of 100 cm. IS : 2553 (Part 1) – 1990 may be referred for the test.
  • Fragmentation test: This test determines the fracture characteristics of toughened safety glass or other glasses. The specimen is laid horizontally on a surface that supports it over its entire area, and is broken by a punch applied at a predetermined location. The numbers of particles of broken glazing material within a given area are counted. IS : 2553 (Part 1) – 1990 may be referred for the test.
  • Boil test: This test determines the effect of exposure of safety glass to temperature and humidity conditions by boiling. The specimens are immersed in hot water and then boiling water for a specified period of time and inspected for bubbles or other defects. IS : 2553 (Part 1) – 1990 may be referred for the test.
  • Weathering test: This test is carried out to determine the effect of radiant exposure on safety glasses. Specimens are exposed, under specified conditions, to light from an artificial light source. After exposure, safety films are then subjected to the Charpy Impact Test. Safety film backed glass is subjected to a tensile test and an adhesion test. Comparing the test results of the exposed specimens with those of unexposed specimens assesses the effect of the radiant exposure. AS: 2208 – 1996; ANSI Z97.1 – 1984; 16CFR Ch II (1-1-04 Edition), may be referred for the test.
  • Ageing test: This test is carried out for determining the effect of accelerated ageing on safety glazing materials. Specimens are exposed under specified conditions to warm, humid and dry cycles and then subjected to impact test. Comparing the impact test results of exposed specimens with those of unexposed specimens assesses the effect of the accelerated ageing. AS : 2208 – 1996; ANSI Z97.1 – 1984, may be referred for the test.
  • Fracture and adhesion test: Laminated glass is given sudden punch and the fragments from the under surface are collected and weighed. IS : 2553 (Part 1) – 1990 may be referred for the test.
  • Light stability test: The purpose of this test is to ensure that the glazing material is resistant to the effects of exposure to light encountered in service. IS : 2553 (Part 1) – 1990 may be referred for the test.

Annexures

Annexure 1

Sketches of examples for cases 1 to 5,Table A

CASE 1: Vertical walls – Risk of fall but residual protection or Hs >0.75m

AN1

CASE 2: Vertical walls – No risk of fall; Hf < 1.5m & Hs < 0.75m

AN2

AN3

AN4

AN5

CASE 3: Vertical walls – Risk of fall; Hf >1.5m & Hs < 0.75m

AN7AN8

AN9

CASE 5: Glass acting as a balustrade / handrail

AN10

Annexure 2

Coorelation between maximum glass area and glass thickness (impact load) Recommendatory.

A: FOUR SIDES FRAMED GLASS

In case of framed glass panels supported on four sides starting between the finished floor level and less than equal to 750 mm as described in case 2 & case 3 given in table A the maximum allowable area of the glass panel is as follows:

a) The maximum area of the normal or annealed glass less than equal to 0.5 sqm. Refer annexure 3.

b) The maximum area of the safety glass with respect to its thickness shall be with in the permissible maximum area as defined in the table C below.

AN11

Table C

Type of glass
Nominal Thickness
Maximum Allowable area (sqm)
Tempered Safety Glass
4
5
6
8
10
12
2
3
4
6
8
10
Laminated Safety Glass
6
8
10
12
2
3
5
7
In case of laminated glass the thickness of PVB is not accounted

c) In case of glass panels supported on all four sides starting above greater than or equal to 750 mm or a protection / transom / chair rail is in place permanently from the finished floor level as given in Case 1, table A, the thickness of annealed glass shall be with in the permissible maximum area as defined in table D below.

AN12

Table D

Nominal Thickness (mm)
Maximum Allowable area (sqm)
4
5
6
8
10
12
0.8
1.2
2.1
3.2
4.4
6.3

B: TWO / THREE SIDES FRAMED GLASS

In case of glass panel supported on two/ three sides starting` greater than or equal to 750 mm or has a protection from the finished floor level as given in Case 1, table A, then annealed glass can be used in following cases as mentioned in table E else tempered or laminated glass shall be used.

Table E

Nominal Thickness (mm)
Maximum allowable height of glass (m)
Maximum allowable glass area (sqm)
6mm
8mm
10mm
< 1.2
> 1.2 to < 1.6
> 1.6 to < 2
0.9
1.8
2.7

AN13

B: FRAMELESS / NON-FRAMED GLASS

In case of frameless or non-framed glass panel toughened safety or laminated safety glass shall be used. The thickness of safety glass and corresponding maximum permissible area is given in the following table F:

Table F

Nominal Thickness (mm)
Maximum Allowable area (sqm)
6
8
10
12
3.0
4.5
6.0
7.5

In all above cases and in cases wherein the glass area exceeds 7.5 sqm. it is recommended to check and determined thickness of the glass using finite element analysis under wind load as per IS : 875 (Part 3 1987; reaffirmed 1997) for external glazing and / or loads

AN14

given in table J, in case of internal glazing or glazing wherein there are chances of human impact.

C: POINT SUPPORTED GLASS For point fixed system the glass area and glass thickness shall be determined by the specific strength analysis and type of point fixing hardware.

Note: If Insulating Glass Unit (IGU) is used in situations mentioned in this guide then any one of the following will apply:

i) If IGU is installed in areas subjected to h u m a n impact on either side then both the panes of the unit shall meet the requirements of this guide. The maximum area specified may be multiplied by 1.5 provided that each of the component glass of the unit otherwise complies with the relevant guidelines of this guide.

ii) In situations where access is restricted to one side of the unit, then only the accessible side should meet the requirements of this guide without the application of above- mentioned factor of 1.5.

Annexure 3

Glass Thickness Calculation (wind load) – Recommendatory*

A. WIND LOAD CALCULATIONS

The thickness of the glass supported on all four side to be used in façade, window panels is governed by the following factors:

a) Area to be covered by the window panel.
b) Aspect ratio of window panel (length / breadth) or (longer side / shorter side).
c) Effective wind pressure at the window height
d) Strength/load bearing capacity of glass to be used.

The empirical relation between the wind pressure, area of the glass panel and the required glass thickness is as follows:

Pnet * A = 200.0 * Tk (T < 6 mm)
Pnet * A = 200.0 * Tk + 1900 (T > 6 mm)

Wherein, Pnet = Net design wind pressure (N/m2)
A = area of glass panel (m2)
T = SNT or the standard nominal thickness (mm),
k = is a constant as shown in table H

Determining Pnet:

The wind pressure computation is based on the procedure given in IS: 875 (Part-3) 1987, (Reaffirmed 1997).

Net wind pressure (Pd), may be defined using the following equation:

Pd = Pz x Cp

where, Cp = Net pressure coefficient as per IS: 875 (Part-3) 1987

Depending upon the type of processed glass used net design wind pressure (Pnet) can be calculated as given below:

Pnet = Pd /Pf

Wherein, Pf is the pressure factor dependent on the type of glass as shown in the table G.

Table G: The values of the pressure factor Pf

S. No
Glass Type
Pf
1.
2.
3.
4.
5.
Normal (Annealed)
Laminated
Tempered
Insulating
Heat Strengthened
1.00
0.80
2.50
1.50
1.60

Table H: SNT and Corresponding ‘k’ values

‘T’
‘K’
‘T’
‘K’
3 mm
4 mm
5 mm
6 mm
8 mm
1.683
1.732
1.753
1.765
1.570
10 mm
12 mm
15 mm
19 mm
25 mm
1.578
1.583
1.579
1.569
1.569

Limiting Aspect Ratio (ARMAX):

The design of the thickness using empirical relation in as detailed above will be valid upto a limiting aspect ratio ARmax. The value of ARmax for different SNT of glass is shown in the following table I

Table I: SNT and Corresponding ‘ARmax.’ value

SNT
ARmax
SNT
ARmax
3 mm
4 mm
5 mm
6 mm
8 mm
7.3
6.8
6.5
6.3
5.9
10 mm
12 mm
15 mm
19mm
25 mm
4.9
4.3
3.8
3.3
2.9

Side panels, partitions etc on the sides of the walkway, which can be subjected to human impact, need to be designed considering guarding loads given in table J. For four sided supported glass panel the glass thickness required could be calculated by inserting this loads in place of wind load.

Table J: In case of side panels – Design loads in different buildings

Type of Buildings
Line load UDL KN/m run
UDL (infill) KN/ sq m
Point Load KN
Residential 0.36 0.5 0.25
Office Building, Hotels,
Hostels, Library, Museum,
Hospital & Schools
0.74 1.0 0.50
Cinema, public buildings
& points of assembly
3.00 1.5 1.50

Where UDL means Uniformly Distributed Load

B. OTHER AREAS

For other areas not mentioned in this annexure refer to the previous clauses.

* Reference – Use of Glass in Building, by Shri N.K. Garg, Scientist, Central Building Research Institute (CBRI), Rourkee

Annexure 4

Definitions

For the purpose of this guide the definitions given below will apply:

Area: The area of a panel between sightlines after glazing, calculated using the sight size.
Annealed Glass: Another term for “ordinary” glass, most commonly used for float glass.
Aspect Ratio: The ratio of a longer side of panel to its shorter side.
Balustrade: A low wall forming a parapet to a stair, ramp, balcony, raised level, or a change in level.
Back Putty: The portion of the putty remaining between the glass and the depth of the rebate after the glass has been pushed into position.
Beads or Glazing Beads: A strip of wood, metal or other suitable material attached to the rebate to retain the glass.
Bite: The width of silicone used to bond the fin or frame member to the edge of the glass panel.
Bedding Putty: The compound placed in the rebate of the opening into which the glass is bedded.
Bent Glass: Flat glass that has been shaped while into hot cylindrical or other curved shapes.
Bevelling: The process of edge finishing flat glass to a bevel angle.
Block (Setting Block): A small piece of wood, lead or other suitable material used between the edges of the glass (generally the bottom edge only) to centralize the glass in the frame (frequently called a setting block).
Building: A structure, constructed with any matrials whatsoever for any purpose whether used for any habitation or not and includes – “Assembly building”, which means a building or part thereof where groups of people congregate or gather for amusement, recreations, social, religious, patriotic, civil, travel and similar purpose. “Assembly building” includes buildings of drama and cinema theatre, drive-in-theatres, assembly halls, city halls, town halls, auditoria, exhibition halls, museums, mangal karyalayas, skating rinks, gymnasia stadia, restaurants, eating or boarding houses, places of worship, dance halls, clubs, gymkhanas, road, air, sea or other public transportation stations and recreation piers.
Business Building: Any building or part thereof used for transaction of business and / or keeping of accounts and record therefore offices, banks, professional establishments, court houses being classified as business buildings, if their principal function is transaction of business and / or keeping of books and records.
Chair Rail: A fixed glazing bar, or rigid push bar, that provides protection from human impact.
Clear Glass: Transparent glass.
Conbustible material: The material which when burnt adds heat to a fire when tested for combustibility in accordance with the IS 3808-1966: Method of Test for Combustibility of Building Materials, National Building Code.
Corridor: It means a common passage or circulation space including a common hall.
Distance Piece: A small piece of wood, lead or other suitable material used to locate the glass between the bead and the back of the rebate, and prevent lateral movement.
Door: A hinged, sliding or otherwise supported openable barrier providing entrance to and exit from a building, corridor or room. Doors may be framed or unframed.
Double Glazing: Glazing that incorporates two panels, separated with an air space, for the purpose of sound insulation or thermal insulation or both.
Edge Polished: Usually applied to flat glass, the edges of which have been polished after cutting.
Edging: Grinding the edge of flat glass, to a desired shape or size.
Exposed Edge: A glass edge that is not covered.
External Wall: An outer wall of a building not being a party wall even though adjoining a wall of another building and also means a wall abutting on an interior open space of any building.
Faceted Glazing: Flat panes of glass installed vertically at an angle to each other, to form a faceted curve.
Fin: A piece of glass positioned and fastened to provide lateral support.
Fire resistant: It means the time during which a fire resistant material i.e. material having a certain degree of fire resistance, fulfills its function of contributing to the fire safety of a building when subjected to prescribed conditions of heat and load or restraint. The fire resistance test of structures shall be done in accordance with IS 3809-1966 Fire Resistance Test of Structure.
Fire Separation: It means the distance in metre measured from any other building on the site or from another site or from the opposite side of a street or other public space to the building.
Flat Glass: A general term covering sheet glass, float glass and various forms of rolled and plate glass.
Float Glass: A form of flat glass produced by reheating the continuous ribbon of glass whilst it floats over a bath of molten metal.
Frame: A structure manufactured from timber, metal, glass or other durable material or combinations of materials such as glass fins and structural sealant, supporting the full length of a glazed panel edge.
Frameless Glazing: See unframed glazing.
Front Putty: The compound forming a triangular fillet between the surface of the glass and the front edge of the rebate.
Fully framed glazing: Panels that have all edges framed.
Glass: An inorganic, non-metallic material produced by the complete fusion of raw materials at high temperatures, into a homogeneous liquid, which is then cooled to a rigid, condition essentially without crystallization.
Glazing: The securing of glass in prepared openings in windows, door panels, partitions and the like.
Guarding: Glass used to prevent people falling wherever there is a change in floor level by means of a permanent barrier.
Heat Soaking: Heat Soaking is done on toughened glass by reheating to a temperature of 290 oC and keeping it at this temperature for eight hours and cooling it gradually. The glass can break spontaneously and without provocation due to possible impurity of Nickel Sulphide in basic glass used for tempering. This risk of spontaneous breakage can be minimised by heat soaking process by forcing such glasses to break in the factory itself.
Heat Strengthened Glass: Glass which has been heated past its softening point and chilled rapidly to increase its strength and make it thermally safe, but which breaks like annealed glass.
Heat Strengthened Laminated Safety Glass: Laminated Safety Glass utilizing two or more panels of heat-strengthened glass in the make up.
Infill balustrades: Balustrades in which the supported glass resists an infill pressure and / or point load applied to the glass panel.
Insulating Glass Unit (IGU): The standard configuration for residential and commercial windows consisting of a sealed unit of two panes of glass separated by a metal spacer.
Internal Partition: An interior dividing wall or such portion of an interior dividing wall that is not a door, side panel, shopfront or atrium wall.
Laminated Glass: A composite material consisting of two or more sheets of glass permanently bonded together by a plastic interlayer material.
Laminated Safety Glass: Laminated glass that satisfies the requirements for a safety glazing material according
to this guide.
Maximum Thickness: The thickness of a panel of glass at the maximum thickness tolerance.
Manifestation: Any technique for enhancing a person’s awareness of the presence of transparent glazed areas.
Minimum Thickness: The thickness of a panel of glass at the minimum thickness tolerance.
Mirror: A piece of glass silvered on one side, with a protective paint coating.
Nominal Thickness: A numeric designation used for reference purposes that indicates the approximate thickness of glass.
Non-combustible: It means not liable to burn to add heat to a fire when tested for combustibility in accordance with the IS:3808-1966, Method of Test for Combustibility of Building Materials.
Non-residential Buildings: Buildings other than those defined above such as hotels, hostels, motels, shops, offices, schools, public assembly buildings, and factories and those parts of the residential buildings common to a group of dwellings such as common circulation areas in blocks of two or more flats.
Safety organic-coated: A glazing material consisting of a piece of glass coated and permanently bonded on one or both sides with a continuous polymeric coating, sheet or film, which meets the test requirements of the safety glazing standards.
Pane: Single piece of glass cut to size for glazing.
Panel: An assembly containing one or more panes.
Parapet: It means a low wall or railing built along the edge of the roof or a floor.
Partition: It means an interior non-load bearing divider, one storey or part storey in height.
Partly framed glazing: Panels that have one or more edges unframed.
Rebate: The part of a surround; the cross section of which forms an angle into which the edge of the glass is received.
Residential Buildings: Buildings and such portions of buildings used as separate dwelling houses and flats, but not incorporating common circulation areas in blocks of two or more flats.
Residual protection: It is the protection provided to avoid the impact of human being to glass. It is provided on the side of glass where there are chances of Human impact. It can be achieved by providing a sill structure or a grill inside.
Shower doors, shower screens and bath enclosures: The panels, doors or windows a enclosing or partially enclosing a shower or bath.
Side Panel: A panel (operable or inoperable) located adjacent to a doorway. It may or may not be in the same plane as the doorway.
Sloped overhead glazing: Glazing that is inclined at less than 75 degrees to the horizontal and located, wholly or partially, directly above an area that may be used by people.
Span: The dimension between supports. For panels supported on all four edges, it corresponds to the smaller of the sight size dimensions.
Spandrel: That portion of the exterior wall of a multistory commercial building that covers the area below the sill of the vision glass installation.
Toughened laminated safety glass: Laminated safety glass utilizing two panels of toughened safety glass in the make up.
Unframed glazing: Panels without framed edges.
Wardrobe doors: Doors that provide access to built in storage areas, excluding those fitted to pieces of furniture that are not built into the building.
Window: It means an opening other than a door, to the outside of a building which provides all or part of the required natural light, ventilation.
Window Sill: Solid wall (Brick or concrete wall) starting from the finised floor level to the base of first window or structural member consisting of a continuous horizontal metal/wooden forming the lowest member of a framework or supporting structure.

Annexure 5

Definitions

Relevant Codes / Standards / Publications

For the purpose of making this document the following codes / standards were referred:

– IS : 2553 (Part 1) – 1990 – Safety Glass – Specification.

– IS : 2835 – 1987 – Specification for Flat Transparent Sheet Glass (third revision)

IS : 875 (Part 3) Reaffirmed 1997 – Codes for the Wind Loads.

– IS : 3548 – 1988 – Code of Practice for Glazing in Buildings

– IS : 10439 – 1983 – Code of Practice for Patent Glazing

– IS : 7760:1985 – Specification for steel glass-front cabinet

– 16CFR Ch II (1-1-04 Edition) – Part 1201 – Safety Standards for architectural glazing materials.

– ANSI Z 97.1 – 1984 (R1994) – Safety Glazing Materials – Used in Buildings – Safety Performance Specifications and Methods of Tests.

– AS: 2208 – 1996 – Safety Glazing Materials in Buildings

– AS 1288 – 2006 – Glass in Buildings – Selection and Installation.

– BS : 6206 – Part 4 – 1995 – Specifications for impact performance requirements for flat safety glass and safety plastics for use in buildings

– BS : 6262 – Part 4 – 1994 – Code of Practice for Glazing for Buildings – Safety related to Human Impact

– BS : 6262 – Part 6 – 1997 – Code of Practice for Glazing for Buildings: Special Applications

– BS : 952 – For nominal thickness of glass.

– BS : 8000 – part 7 – 1990 – Workmanship on Building Sites – Code of Practice for Glazing

– BS : 5516-1 – 2004 – Patent Glazing and Sloped Glazing for Buildings – Code of Practice for Design and Installation.

– BS : 8213 – Part 4 – 1990
– Windows, Doors and Rooflights: Code of Practice for the Installation of Replacement Windows and Doorsets in Dwellings

– BS EN : 12600 – 2002 – Glass in buildings – Pendulum tests – Impact test method and classification for flat glass

– BS : 7499 – 1991 – Specification for inclusion of glass in the construction of furniture, other than tables or trolleys, including cabinets, shelving systems and wall hung or free standing mirrors

– BS : 7376 – 1990 – Specification for inclusion of glass in the construction of tables or trolleys

– BS EN : 1727 – 1998 – Domestic furniture, storage furniture, safety requirements and test methods

– BS EN : 1153 – 1996 – Kitchen furniture, safety requirements and test methods for built-in and free standing kitchen cabinets and work tops

– JIS R 3206 – 1997 – Tempered Glass

– JIS R 3205 – 1997 – Laminated Glass

– DIN 52 337 – Methods of testing flat glass for use in buildings – pendulum impact tests.

– Glass Association of North America Installation Guide.

– Use of Glass in Building, by Shri N.K. Garg, Scientist, Central Building Research Institute (CBRI), Rourkee.