1 FIRE SAFETY OF BUILDING ENVELOPES IS YOUR BUILDING SAFE ? BCO - - PowerPoint PPT Presentation

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FIRE SAFETY OF BUILDING ENVELOPES

IS YOUR BUILDING SAFE ?

BCO Presentation – 22 November 2019

Kobus Strydom

www.firelab.co.za

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Historical

Sao Paulo High-rise fire First extensive evaluations in USA First large-scale facade test in SA New Building Regulations – 1987 Future trends

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Question…

What is the difference between a building envelope and a division in terms of the Building Regulations ?

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Introduction

The situation abroad ?

» London » Australia » Middle East

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Current situation in South Africa Part T, Fire Protection

Standard Building Regulations – since 1963 National Building Regulations – since 1987 First revision – 1990 Previous revision – 2011 Currently under review

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Statutory Requirements Part T, Fire Protection

Regulation T1 (1) and (2) – General requirements Regulation T2 – Offences

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Regulation T1 (1) Any building shall …..

Safe escape Limit spread of fire Structural stability Limit spread of smoke Access to building and equipment

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Regulation T1 (2)

The requirements of T1 (1) shall be deemed to be satisfied where the design, construction and equipment of any building –

(a) Is the subject of a Rational Design …… (b) Complies with SANS 10400 – T: Provided …..

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Requirements in terms of the Deemed-to satisfy Clauses

Set simple basic solutions that will satisfy the requirements contemplated by SANS 10400 – T Although aimed at simple designs it addresses most design principles for even complex buildings

» Very often it is more important to focus on the intent of the requirement rather than the words in the respective Clause » The respective Clauses set out the minimum requirements

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Requirements in terms of the Rational Design

The alternative design must meet the requirements contemplated by Regulation T1 (1)

» The design have to focus on basic principles rather than detail implied by the deemed-to-satisfy rules, however, it is always handy as check list to ensure all aspects are covered » The principle of a Rational Design should always be equal or better and not better than nothing

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Requirements for consideration

Compartmentation or divisions within a building Fire Resistant requirements (walls or panels) Fire properties of structural elements or systems Passive fire protection requirements Active fire protection requirements Division and Fire separating elements Service penetrations

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(Cont.)

Material requirement and selection Material testing requirements System testing requirements Combustibility of materials Vertical and lateral flame spread (external) Safety distances

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Typical Building Designs

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A non-combustible facade with insulation

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A non-combustible facade with windows

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A non-load bearing frame facade system

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An upstand with non-load bearing frame facade system

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A smoke and fire seal with a non-load bearing frame facade system

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Detail of a upstand and smoke and fire seal with non-load bearing frame facade system

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Vertical fire separation with a non-combustible facade

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Vertical fire separation with a non-load bearing frame facade system

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Testing requirements

(SANS 10400 – T)

Fire Resistance – SANS 10177 – 2 Surface Fire Index (flooring) – SANS 10177 – 4 Surface Fire Index (int. finishes) – SANS 10177 – 3 Combustibility – SANS 10177 – 5 Basic fire properties – SANS 10177 – 9 Basic fire spread properties – SANS 10177 – 10

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(Cont.)

External fire spread properties of wall façade systems (New SANS 8414 – 1 & 2) SANS 8414, Part 1 and Part 2, was finally adopted as a new test method for the evaluation of building facade walls in 2018 (approximately 5 years for adoption)

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Fire testing in general

Small-scale testing

Except for SANS 10177 – 2 and SANS 8414 – 1 & 2 all the other test methods are intended to determine the burning characteristics or the basic fire properties or classification of materials Similarly EN 13501 only classify materials for comparison and not suitability for intended use

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Fire testing in general

Large-scale testing

SANS 10177 – 2 , Fire Resistance Rating (FRR) of a building element or system to determine

Structural Stability – (R) Integrity – (E) Insulation – (I)

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(Cont.)

SANS 8414, Part 1 and Part 2, Fire performance of external cladding systems (non-loadbearing and loadbearing systems respectively)

Although large-scale testing of facade systems were conducted in SA, this test method was primarily adopted as a result of the new energy legislation requiring buildings to be insulated

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Effect of new Energy Legislation

SANS 204 and Fire Safety of Buildings

Prior to the new legislation the fire safety of building facade walls were already a concern Shortcomings in existing facades were clearly demonstrated by our limited fire history The use of thermal insulation on buildings can result in a major fire risk and is common in SA like the rest of the world

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Fire safety requirements to be considered

Designer must have a clear and comprehensive understanding of all the relevant requirements pertaining to the building (internal and external) The Regulation only states the end result The deemed-to-satisfy Clauses can provide guidance to ensure all aspects are covered

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(Cont.)

Although the deemed-to-satisfy Clauses are not Regulations, it provides valuable information if the intent of the Clauses are clearly understood REMEMBER ! – Fire safety design can be summed up in a single word – DETAIL, DETAIL, DETAIL …..

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Compartmentation

Regulation T1 (1) (b) states that the fire must be contained to the area of origin Therefore the following must be considered: Horizontal dividing elements (floors and roofs?) Vertical division and separating elements including protected openings

» Dividing walls (occupancy separating) » Internal walls (tenancy separating)

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(Cont.)

External walls with consideration to:

Vertical division separating elements Horizontal division separating elements Protection of openings (windows, fire and smoke seals) Loadbearing or non-loadbearing Structural stability of the frame system

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(Cont.)

Structural protection of connecting components Fire properties of materials and construction components Fire stops within the system Assembly details Safety distances (if relevant)

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(Cont.)

External cladding

Fixing method Composition and fire properties of the materials External weather protection Fire properties of the system Fire stops or fire breaks

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Buildings System and Materials

Wall types – FR, F and N Structural (walls or panels)

» Load bearing or non-load bearing

Walls

» External » Internal » Divisions » Division separating elements

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Fire safety concepts

Combustibility & non-combustibility Fire Resistance Spread of Flame Fire Retardancy

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Test requirements

» External

• SANS 10177, Part 2 (Building elements)
• SANS 8414, Part 1 and Part 2 (Cladding & Facade walls)

» Internal

• SANS 10177, Part 3, 4, 5, 9, 10 (Internal finishes)

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Combustibility

SANS 10177 – 5: Combustibility of building materials at 750 °C

Increase furnace temp. by more than 50 °C or flaming for more than 10 seconds Plastics – combustible by this definition

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Fire Resistance

SANS 10177 – 2: Fire resistance testing of building elements

Stability (Loadbearing or non-loadbearing) Integrity – no burn-through Insulation – unexposed side 140 °C plus ambient average or 180 °C plus ambient maximum Physical property of a system rather than any particular component Combustibility – not always relevant – non-combustible materials could have poor fire resistance Addition of fire retardants to product has little if any effect on fire resistance

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ISO Standard Time-Temperature Curve

T = 345*log(8*t+1) +Ta

Where T = furnace temperature (°C) t = time (minutes) Ta = ambient temperature (°C)

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ISO Standard Time-Temperature Curve

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ISO Standard Time-Temperature Curve

After 30 minutes; T = ± 850 °C After 60 minutes; T = ± 950 °C After 120 minutes; T = ± 1 050 °C

Fire Resistance Notations

“F or RE” – Stability & Integrity, no insulation “FR or REI” – Stability, Integrity & Insulation

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Spread of Flame

SANS 8414, 1 – 2: Fire performance of external building cladding systems (Criteria)

Stability (Loadbearing or non-loadbearing) Integrity – no burn-through Insulation – unexposed side 140 °C plus ambient average or 180 °C plus ambient maximum Physical property of a system rather than any particular component Combustibility – not always relevant – non-combustible materials could have poor fire resistance Addition of fire retardants to product has little if any effect on fire resistance

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SANS 8414 – Part 1

Insulated cladding on a non- combustible substrate

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SANS 8414 – Part 2

Non-load bearing frame facade system

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Spread of Flame considerations

External effects Fire breaks and separations and Safety distances Internal aspects Classification of internal finishes Design considerations Test requirements

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External effects

» Spread from point of origin » Spread beyond fire divisions » Spread to adjacent buildings » Exposure to radiation and resulting effects

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Internal aspects

» Wall finishes » Floor finishes » Interior design » Classification of materials used » Limitations

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Design requirements

» Type of material or system » Type of building (office, residential or other) » Internal or external » Exposure conditions

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Conclusion

The designer must have a clear and comprehensive understanding of the Building Regulations Fire properties of materials are not enough to design a building envelope The fire safety of a building envelope or cladding system can only be determined by means of large- scale testing of the entire system

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Conclusion

Non-combustibility does not imply fire resistance nor structural stability (compare wood and steel) Surface fire spread and radiation are linked and important for the correct consideration of safety distances Both fire retardancy and fire resistance are important parameters but they are not strongly linked

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Conclusion

The design of the cladding system also needs to incorporate other fire safety requirements Applicability within the building regulations needs to be understood

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Conclusion

The effect of inappropriate material or system used in construction of a building envelope may have a major effect on structural stability and may result in loss of life and property Innovative systems, if used correctly, can provide a safe alternative to conventional construction provided it conforms to the Statutory requirements

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What is the answer to the question ?

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Questions

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Let us create a better and safer built environment for all

• f South Africa

Thank You