Friday, March 02, 2007

MSc Dissertation Fire Resistance in Historic Buildings, UK

Copyright: University of Portsmouth UK, September 2001

By: L.A. Wahab

ABSTRACT

Over the centuries, fire has continually caused injury, loss of life and destruction of property. Fire can also destroy the national priceless heritage, which is historic buildings. It has been accepted as a fact, that as buildings become older, the less fire protection is required. Hence, more people are placed at risk from fire than before. An outbreak of fire in historic buildings often has more serious consequences than it has on a modern building. This is because of the large amount of timber in the construction and the building structure and fabric is weak in fire resistance. Many historic buildings in Portsmouth are considerable of architectural and historical importance and their destruction by fire is an irreplaceable loss. It should be well kept and protected from fire danger at all time. Lessons of major fires in historic buildings such as Hampton Court Palace and Windsor Castle, is that every building should have a good fire resistance to prevent fire from outbreak. Fire resistance is one of the ways to minimise the outbreak of fire from destroying historic buildings. Most historic buildings is built with fire resistance materials, which is by today’s standards, fall far below the required performance with regard to Building Regulations and Fire Precautions Act. Effort should be made to upgrade fire resistance at historic buildings to make sure that it is safe from fire danger and on the other hand, concerned with preserving the building fabric without destroying or changing the features of existing building. This dissertation will look into the technique and method of upgrading fire resistance in historic building and the building elements is limited to walls, floors, roofs and doors only. The appropriate of this research is to find out the best solution to prevent fire from threatening or destroying the structure and the contents of historic buildings which is rich in artistic values. Basically in designing and upgrading fire resistance in historic building, a large number of steps should be taken by architect, conservators, planner, builder and fire authorities to deal with features of construction, internal planning and in some cases furnishings that will not effect the special architectural or historical character of the buildings. By doing this research, it is hope that it could contribute some changes as perspective approach leads to more technique and method of upgrading fire resistance in historic buildings.

ACKNOWLEDGEMENTS

I would like to express a special depth of gratitude to my employer, UiTM who gives an opportunity to me to pursue a master degree in MSc Historic Building Conservation, and thanks to their support morally and financially. My appreciation to Dr. Ayman Nassif, my supervisor, for his guidance and encouragement to make this dissertation a reality and Dr. Robert Otter, my course leader for his consent, advice and assistance. Special thanks to Assoc. Prof. Dr. Rosman Ahmad for the time and assistance reviewing this dissertation. In addition, to all owner of historic buildings in Portsmouth for their time and respond, to the development of this dissertation. Finally, I am grateful for the support and understood of my beloved hubby, Kamarul who is there for me at all time, and not forgotten to my son El’ Haicarl. Thanks for being with me.

LIST OF ABBREVIATIONS

BRE
Building Research Establishment.
BS British Standard.
CP Code of Practice.
DOE Department of Environment.
FPA Fire Protection Association.
FSE Fire Safety Engineering.
GLC Greater London Council.
HCC Hampshire County Council.
HOFD Home Office Fire Department.
NFPA National Fire Protection Association.
PCC Portsmouth City Council.
UK United Kingdom.
BSI British Standards Institutions.

CHAPTER 1 INTRODUCTION
1.1 BACKGROUND INFORMATION

Over the centuries, fire has continually caused injury, loss of life and destruction of property, particularly in urban areas. Fire has caused a lot of destruction and many deaths. Tragedy such as those of the Great Fire of London which occurred in 1666, the ones in Summerland in the Isle of Man in 1973 and King’s Cross Underground station which occurred in 1997 are some examples. Each year fires in buildings in the United Kingdom (UK) resulted in more than 800 deaths and over 15,000 injuries mainly due to fire in buildings. Fire, hence, has causes major property loss, which has been estimated to be more than £1,000 million direct losses each year in the UK. These fires can pollute the environment via contaminated firefighting water and by the emission of particulate and toxic fumes into the atmosphere. Fire can also destroy our priceless heritage - the listed buildings. National Regulations and Codes of Practice mitigate the effects of fire in or near historic buildings. Over the past two decades, the Building Regulations in the UK have moved from comprehensive prescriptive regulations to brief functional regulations supported by non-mandatory detailed technical guidance. The UK has a good record of fire safety in buildings. It has been accepted as a fact, that as buildings become older, less compartmentation is required. Hence, more people are placed at risk from fire than before. Fire can also destroy priceless heritage, most particularly if it occurred to historical buildings. There are two primary factors that must be considered. The first to be considered is the protection of the persons living, working or visiting the historic premises. Secondly, is the protection of the building fabric and its content. Therefore, conserving or adapting a historic building to new uses is more difficult rather than building a new building. In adapting buildings to meet new uses and modern standards, it will need some physical changes to the existing one. It may involve major or minor upgrading to produce better quality building. One of the aspect that should be considered as significance, is to ensure that the building complies with current regulation where applicable, and this invariably requires the physical upgrading of certain elements particularly with regard to fire protection. An outbreak of fire on listed buildings often has more serious consequences than it has on a modern building. This is because of the large amount of timber in the construction and secondly because water supplies are frequently meagre in old buildings. Many of these buildings are considerable of architectural or historical importance and their destruction by fire is an irreparable loss. One of the most important lessons of major fires in historic buildings, such as York Minster, Hampton Court, Uppark House and Windsor Castle, is that every building should have a good fire resistance to prevent fire from outbreak. Fire resistance is one of the ways to minimise the outbreak of fire from destroy the historic buildings. Most of the historic buildings contain fire resistance, which by today’s standard, fall far below the required performance with regard to the regulations. It is our responsible to upgrading fire resistance system to make sure the building is safe from fire danger. The relative priorities for life safety and historic building protection will be viewed differently by those involved in the specification and definition of requirements. The fire authorities or the local fire brigade will be primarily concerned with ensuring the optimum standards are achieved for the provision of means of escape and for the inclusion of means of fire fighting. Meanwhile conservationist on the other hand is primarily concerned with preserving the building fabric without the intrusive effects and loss of fabric that are inevitable consequences of most standard fire resistant measures. The owner of historic buildings is therefor left in somewhat of a dilemma. What are the legal requirements? What life safety standards should be considered for the current and future usage and occupancy? What provisions should be made to protect the building and its contents against the ravage of fire? What are the building elements that need to be upgraded in term of fire resistance? What is the risk? These questions cannot be easily answered. The only requirement in law concerns the provision for life safety and adequate means for escape not the protection of the building. Furthermore, current legislation under the Fire Precautions Act 1971 relates only to those buildings put to a designated use and unless the building incorporates offices, shop, factory and hotel use, it is likely that the Act and the associated fire certification process will apply. The upgrading of fire safety design standards advocated by the current Building Regulations primarily apply to building work only. However they can affect existing historic buildings where materials alterations are proposed that will effectively upgraded the existing provisions concerned by the regulations. They also apply where there is a material change of use including conversions to form museums, a public building or a dwelling. The Regulations are a relatively recent development responding to historic building techniques and methods of upgrading the fire resistance at their building elements. This is the subject matter that is going to be discussed further in this research.
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1.2 SCOPE OF STUDY

This research will look into the technique and method of upgrading fire resistance in historic buildings that are suitable for conservation to new uses. The study was limited only to historic buildings due to the following reasons:
a) Most construction of the historic buildings is from timber, which is weak in fire resistance.
b) There are lots of valuable items and priceless heritage to be protected from fire in historic buildings.
c) Most of the historic building is fall far beyond nowadays Building Regulation especially in fire protection and prevention.

This piece of research have been carried out on the historic buildings situated in Portsmouth and the area covered in this research are Portsea, Old Portsmouth, Southsea, Fratton and their surrounding. The selection of historic buildings is various including residential houses, museum, theatre, schools, churches and offices. The researcher decided to make the area of study in Portsmouth is because it is easier on getting all the information required on doing the research. Meanwhile the scope of study was limited to upgrading the fire resistance in historic buildings and the building element is limited to walls, floors, roofs and doors only. The limitation is expected to helps the researcher to concentrate more on upgrading techniques and method of fire resistance rather than study the fire resistance in general.

1.3 STRUCTURE OF THE DISSERTATION

This research consists of six chapters. Chapter 1 gives the general introduction and presents the overall content of the whole research. It will give introduction on the subject matter, which is upgrading fire resistance in historic buildings. The scope of study and approach of research is outline to give a clear view of the research. This chapter concludes with the structure of the research. Chapter 2 will discusses about the objective of the research that wants to be achieved. The objective of the research topic will be described clearly and will be divided into the chosen building elements, which is walls, floors, roofs and doors. Chapter 3 is prepared to further discuss in detail about literature review on fire and historic buildings. It will provide some information about the historical background, regulation relating to fire and historic buildings, fire protection for historic buildings i.e. active and passive fire protection and the principles of fire resistance. In this chapter, comments and opinion from different author on related topic will be taken as a guide to the research and it will help the topic looks more realistic. Various technique and method of upgrading fire resistance is described and illustrated in detail in this chapter to make up the mind of the readers regarding the discussion topic and the subject matter. Chapter 4 will provide detail information about the method use in the research. Firstly, it will describe and provide some information about the choice of research methodology used in the research. The second part will discuss about the design of the structured questionnaire. Thirdly, the target or to whom the survey sample is given to followed by pilot study on the methodology used. Lastly it will discuss about the distribution of the questionnaire and the limitations of the survey, which has been done. Chapter 5 will describe in detail about the analysis of the data collected from the questionnaire where the data is tabulated in forms of tables and graphs. Then the data is transform as the research findings or result for the research. The findings are further illustrated in forms of graphs and charts to make it more realistic and easier to be understood. This is the stage where the research is really done. Chapter 6 will conclude the result of findings and gives some recommendation how to upgrade the fire resistance in historic buildings especially to buildings elements such as walls, floors, roofs and doors because these are the most important building elements that fire can spread fire easily in the buildings that need to be upgraded.
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CHAPTER 2 RESEARCH OBJECTIVE
2.1 OBJECTIVE OF RESEARCH

This research is basically about the technique used and the methodology employed to upgrade fire resistance in historic buildings. Before we look further on to the research in detail, we have to first of all, understand the objective of the research. We need to know why do we have to upgrade the fire resistance of some elements at historic buildings and how appropriate is the upgrading process and construction to the fire resistance in historic buildings according to the requirement of Building Regulations and Fire Precautions Act. As we all know that most historic buildings have been made from various building materials and it was definitely different from today’s construction. At the beginning, the concept of built the buildings is as a shelter from weather. The builders only concerned to built a safe and comfortable building without thinking about fire protection to the buildings. Nowadays, the concept has changed. Fire resistance becomes one of the priorities and was part of the Building Regulation. Fire resistance has been one of the aspects of the building’s design. But old buildings, which are not, comply with the Building Regulations and Fire Precautions Act must therefor upgrade the fire resistance at their buildings to get an approval of Safety and Health Certificate from the authority. The importance of fire resistance to historic buildings is, when the fire occurs, fire resistances will basically helps to provide the building elements:
a) Resistance to collapse or excessive deflection.
b) Resistance to passage of flames and hot gases.
c) Resistance to excessive temperature rises on exposed face.

Therefore the appropriate of this research is to find out the best technique and method to prevent fire from threatening or destroying the structure and the contents of historic buildings, which is rich in artistic values. The technique and method of upgrading fire resistance in historic buildings is different from new building because of its speciality. Most of them is listed building and under control by the government. Special body which is called English Heritage was responsible in protecting the interest of historic buildings from been threat. English Heritage will try to make sure that there will be no big alteration have been done while upgrading fire resistance in the historic buildings which will destroy and changes the features of existing building. It is because most of the element that form the building has its own particular valuable value of architectural or historical interest that need to be protected and well kept. Recent tragic history has shown, as with the fires at Hampton Court Palace and Windsor Castle, that building elements can contribute the propagation and rapid spread of fire therefor it need to be upgraded. After knowing the importance of upgrading fire resistance in historic buildings and the appropriate of it, we can now concentrate to the objective of the research. The main objective of this research is as mention before to upgrade fire resistance at historic buildings, where most of them can be categories as old buildings. The main objective of this research is as follow:
a) To establish the important of fire resistance to historic buildings.
b) To determine either fire resistance has been upgraded in historic buildings.
c) To developed the technique and method for upgrading fire resistance in historic buildings without changing the features of existing buildings.

These objectives can be achieved successfully by dividing the research topic into four most important building elements that need to upgrade from fire. The elements is as follow:

2.1.1 WALLS

Walls are one of the most important elements because it forms vertical boundaries for fire from spreading out from and in the building. Most historic buildings used partition walls made from timber as their internal walls, which is weak in fire resistance. Meanwhile for the external walls, there are various types of building materials used such as brickwork, masonry, blockwork and also mud and cob. Basically different types of wall need different technique and method of fire resistance. Sometimes the wall has fulfil the Building Regulations and Fire Precautions Act like cavity walls and sometimes it need to be upgraded like most timber partition walls. Therefor some of the historic building need to upgrade their fire resistance at walls and at the same time tried not to change or replace the walls because it will reflects the look of the building.

2.1.2 FLOORS

Floors are also important because it forms horizontal boundaries for fire from spreading out to the upper level of the building. Most suspended ground and upper floors at historic buildings are made from timber at their structure and finishes. Timber floors are the only floors likely to require the upgrading of fire resistance compare to other forms of floors such as concrete floors. Basically by changing or replacing the type of floor will affect the cost and will also change the features of the existing floors. Therefore most of the building owner will find to use a suitable alternative method to keep the floor with good fire resistance.

2.1.3 ROOFS

Roofs are important to historic buildings because it will give the first impression of the whole buildings and also to protect the building from weather. The ability of roofs to resist penetration from fire will depend upon two factors, which is the type of structure and nature of roof covering. Pitched roofs are the only roofs likely to require the upgrading of fire resistance compared to flat roofs. In case of fire, it will spread through roofs if it is not well protected and further destroy the internal part of the building if it collapsed. Therefore the upgrading of fire resistance to the roofs is important especially the structure and the best technique and method is by doing it internally without making a big changing to the external covering which will effect the historical features of the building.

2.1.4 DOORS

Doors are also important to buildings because during a fire, it can protect the spread of fire from one area to another. Most of the door in historic building is made from carved timber door and panelled door externally and flush door internally. To upgrade fire resistance at doors, the best method is by replacing the old one with fire door but this cant be done due to certain regulations and most of the building owner tried to keep it as it was before because of its historical value. Therefore an alternative way is to upgrade the door without having to change the door that will changes the features of the historic buildings have to be done.

CHAPTER 3 LITERATURE REVIEW
3.1 HISTORICAL BACKGROUND

During the medieval times, dwellings were most made of timber-framed construction with thatched roofs, overhanging eaves and indiscriminate use of combustibles provided all the necessary ingredients for the conflagrations, which followed. In 1136 London, Bath and York suffered severe fire damage. (Shields & Silcock, 1987:2). The first attempt of any significance to legislate for the control of fire spread appears in the London Assize of 1189 by Henry Fitz-Ailwyn, Mayor of London. Another disastrous fire in London in 1212, where it is said that 3,000 people died, led King John to issue an Ordinance, which governed the construction of alehouse in the city. It also required that all wooden houses to be pulled down or altered, no new roofs were permitted in thatch, and existing thatched roof were likely to be demolished if not plastered over. In 1246 the Assize of 1189 were reissued and reaffirmed. During the 14th Century, a move away from centrally located hearts to a position against an outside wall began and until the end of the century, chimneys came into use. Ordinances against the use of timber chimneys were passed the following century in London. The 15th Century also saw the first Act of Parliament relating to fire, which made provisions for fire prevention, fire fighting and penalties against person causing fire in UK. Although building regulations of various kinds had existed in London for centuries, London was still full of closely spaced wooden houses. The Great Fire of London started in the early hours of 2nd September at the end of a long dry summer in 1666 destroyed four-fifth (80%) of the city before being brought under control after burning for four days. The result was the first real positive steps were taken, which is London acquired its first complete Code of Building Regulations and means for its implementation. On September 13th Charles II issued a proclamation of which the basic principles were the wall of all new buildings were to be constructed of brick or stone; the main streets were to be wide enough to prevent spread of flame; existing narrow alleyways were to be considerably reduced in number; and a survey was to be made of all ruins and ownership be shown of every plot. These regulations were embodied in ‘An Act for Rebuilding the City of London’. In 1684 a mutual Friendly Society was formed for assisting members in the event of fire. Earlier attempts at fire insurance were made in 1635 and 1638 when certain London citizens had joined together in a pool to protect householders from losses arising from fire. Following a history of serious fires in Edinburgh, where in Mary’s reign, an ‘Act Regulating the Manner of Building within the Town of Edinburgh’ was passed in 1698, which required that in future no building should exceed five storeys. Throughout the 18th Century various minor Acts relating to London were passed between 1707 and 1772. The Act of 1724 also extended the provisions of the Acts and was superseded by the Fires Prevention (Metropolis) Act of 1774, which lasted seven years without amendments. (Read & Morris, 1993:9-11). Towards the end of the 19th Century it was possible to construct large multi storey buildings, the structural elements of which were non-combustible materials that should have been capable of prolonged fire resistance. The 1844 Metropolitan Building Act, which was based on Fires Prevention (Metropolis) Act of 1774, made few marked changes in constructional requirements for fire. However, even in the most advanced buildings of the period, fires still occurred. Many fire proof buildings were constructed only to be destroyed by a fire, simply because architects had not yet realised that providing structural elements with a degree of fire resistance was not enough. Often the designers’ intention, in providing fire resisting floors for example, was negated because continuous ducts, staircase, shaft, etc. were allowed to penetrate the floors without the provisions of fire stops. (Shields & Silcock, 1987:3). At the beginning of the 20th Century, specific guidance in respect of means of escape and fire precautions had generally not been available before the last war. The first British Standard Code of Practice on ‘Precautions against Fire’ was published in 1948. The regulations in force did not require minimum periods of fire resistance; indeed, the very term fire resisting was not adequately defined. The first building regulations for England and Wales were made in 1965, and their scope (originally based on the 1936 Public Health Act) was extended throughout the Fire Precautions Act 1971 to include means of escape in case of fires. (Read & Morris, 1993:12-18). Little work had been done in attempting to identify the factors, which contributed to fire severity and consequently influenced the nature and quality of protection afforded to buildings especially to buildings with special architectural and historical interest.

3.2 FIRE AND HISTORIC BUILDINGS

Fire is no respecter of historic buildings, nor does regulations and codes for fire protection respect the cultural and artistic values in a historic building. The conservationist’s aim is to protect life, prevent fire and minimise damage caused by fire. Morally the destruction of any historic building by fire is worse than total loss, for the loss could have been prevented in most cases. It is therefore desirable to examine first the cause of fire and then the means of lessening its extent and effect through fire resistance. Basically the main problems in historic buildings can be summarised as follows:
a) Failure to consult fire brigade officers and failure to appoint local fire prevention officers and to organise regular fire drills.
b) Poor standards of management, housekeeping and supervision.
c) The danger from smoking.
d) The danger from cooking operations.
e) Faulty electrical installations.
f) Flammable decorative materials and furnishings.
g) Lack of compartmentation, no internal subdivisions, stairways not enclosed, wall linings not fire stopped and etc.
h) Deficient fire resistance; walls and floors inadequate, doors not fire resisting and etc.
i) Inadequate means of escape; doors, passages, staircases have excessive travel distance; no alternative escape routes and etc.
j) The danger of arson.
k) Lack of master keys and mastered locks. The danger from workmen especially when using flame for repairs work.
l) Possible danger from lightning.

One of the most important lessons of major fires, such as York Minster, Hampton Court Palace, Uppark House and Windsor Castle is that every historic building should have a good fire protection, fire precautions and fire safety measures. The whole building should be viewed jointly; water supply and storage capacity, all weather approaches for fire fighting, the manning of the fire brigade and its response time. The condition of the structure which include the characteristics of flammability, disposition of furnishings and condition of electric wiring should be considered. Prevention of fire to historic buildings depends on creating awareness to owners, professionals, the public and workmen. (Fielden, 1996:233-234). Actions should include:
a) Appoint a fire prevention officer, organise fire drills and rescue practice.
b) Ensure adequate water for fire fighting and good access for fire engines.
c) Identify important risks and danger of fire spread, and eliminates unnecessary hazards.
d) Consult a competent fire engineer.
e) See what can be achieves by compartmentation.
f) Upgrade fire resistance such as at walls, floors, roofs and doors.
g) Consider what early detection system can offer.
h) Consider the merit of sprinkler systems.
i) Make checklists for monthly, weekly and daily routine inspections.

3.3 REGULATIONS RELATING TO FIRE AND HISTORIC BUILDINGS

Damage or loss by fire is a constant threat to historic buildings. Fire safety laws have a history almost as long as the building; indeed, some traditional design features and materials are less inflammable than those being used today. By law, the owner of a building open to the public is responsible for providing adequate fire protection for the occupants, but the necessity of obtaining Listed Building Consent for works will affect the character of a listed building should not be overlooked. The Building Regulations deal with fire protection of the structure in all new buildings and, where alterations are being made in existing buildings. The Fire Precautions Act 1971 sets standards for fire protection, which apply to certain categories of existing buildings. The legislation is not retrospective and can only be enforced when the use of the building is to be changed or when the structure is to be modified. The Fire Precautions Act 1971 is concerned only with the protection of life in the event of fire; it does not apply to the protection of the fabric. The Act is designed to cover all buildings that fall into one of the following categories of use:
a) Recreation, entertainment or instruction, or for any club, society or association.
b) Teaching, training or research.
c) Institutions providing treatment of care.
d) Any purpose involving the provision of sleeping accommodation.
e) Any use involving access to the building by members of the public.
f) The use of the premises as a place of work.

However, at present only certain categories of use have been designated under the Act. It sets standards for:
a) Means of escape and their safe and effective use.
b) Means of fire fighting.
c) Means of giving warning in case of fire.

The Act requires that fire authorities will inspect the premises and grant a ‘Fire Precaution Certificate’ if their standards are achieved. If not, the premises must be upgraded. Application of the Act in an historic building should strike a balance between the two ideas of protection and preservation. The measures should represent the minimum necessary to ensure protection of the building’s occupants while avoiding, where possible, alterations to the architectural character of the building. This may include some compromise between active and passive fire protection measures. (Davey, Heath, Hodges, Ketchin & Milne, 1988:17). Fire regulations are framed chiefly with the design of new buildings in mind, rather than the improvement of existing buildings, and their primary concern is, quite rightly, the safeguarding of life rather than the safeguarding the contents of the building. Historic buildings require wider priorities; it is suggested that the objective should be broken down into three parts:
a) To prevent the outbreak of fire.
b) To minimise the effects of fire by preventing it from spreading.
c) To enable the fire to be fought efficiently with minimum damage to its contents.

To meet the regulations in the UK (Fielden 1996:238), the most typical actions are:
a) Planning alternative protected escape routes, uses of paint or fire retardant to combustible materials such as wood panelling and provision of hatches, crawlways and internal ladders.
b) Forming enclosed staircases, glazed screens and fire doors on magnetic latches and hardwood treads on stairs.
c) Upgrading fire resistance of walls, floors, roofs and doors.
d) Provision of alarms, detectors, emergency lightning and fire fighting equipment such as extinguishers, hose reel and hydrants.
e) Compartmentation with thickening of floor boards or other treatment above the floor joists, fire stopping of cavities and ceiling voids and sealing off ventilation grilles.
f) Provision of sprinklers and reserve water storage for fire fighting.

3.4 FIRE PROTECTION FOR HISTORIC BUILDINGS

The protection of historic buildings from fire damage is important. Many of these buildings were built without much thought given to fire protection. Such things as fire walls and fire stops may not have been incorporated into the structure and many of these buildings utilise wood for much of their framing. A fire in such a building therefore, can quickly spread and cause major damage in a very short time. Most historic buildings were also built with little or no regard for automatic fire detection or extinguishing systems. When designing and installing such systems, careful planning and equipment placement must be utilised to minimise the visual and structural impact of the system to the building. The fire protection specialist is facing with the difficult task of balancing the need for proper fire protection and restoration of the historic fabric of the building. It is not hard to imagine a system where the desire to hide the fire protection systems components results in a system which is minimally effective due to poor placement of these devices. In 1997, the National Fire Protection Association (NFPA) has issued a ‘Standard for the Protection of Cultural Resources’ including museums, libraries, places of worship and historic properties. The documents concern about the historic structures and provide some guidance regarding fixed fire protection systems at these buildings. Basically there is two type of fire protection that can be used in historic buildings known as active and passive fire protection.

3.4.1 ACTIVE FIRE PROTECTION

The strategy for protection of a historic building and its contens according to Fielden (1996:240) depend on preventing the outbreaks of fires, particularly fire caused by human carelessness. For a large historic buildings such as museum, castles, country house, cathedral and etc., a full system of fire warning alarms should be installed, and if necessary, special detectors can reinforce human vigilance and can be wired by direct line to the fire brigade at the cost of an annual rental. Arrangements should be made for a responsible official to be available by day and night in case of fire. An internal telephone or radiotelephone system is invaluable for this. Closed circuit infrared television systems, which can see in the dark, may become more common and be linked with special security systems by direct line to the police station. Locks should be standardised so that the fire brigade can open all relevant doors with one master key. At night all internal doors should be left closed but unlocked, if security permits. Meanwhile for small historic buildings such as villa, terrace, flats and etc., the use of fire detection is the best solution. Fire detectors are designed for the following special circumstances:
a) For hazardous situations: Such as petrol and flammable vapour detectors; butane and propane leakage detectors; over heat detection; and explosion and suppression detection.
b) Ionisation detectors: To detect combustion.
c) Visible smoke detectors: Using light scattering techniques, light obscuring techniques or using sampling systems.
d) Flame detectors: Either ultraviolet or infra red.
e) Laser detectors: Using ultrasonic detection.
f) Combustion gas detectors: To detect combustion.
g) Heat detectors of various types: Such as spot or point detectors; solid state detectors; thermocouples; fusible link either solder or quartzoid bulb; line detectors using capillary tube; or line detectors using cables with flexible joints.

The sitting of detectors in historic buildings demands great care especially in large volumes where height reduces the sensitivity of the detectors. Internal air current can behave differently by day and night when a stratification layer between cool and warm air can form at different levels, so upsetting the functioning of smoke detectors. Unfortunately the number of false alarms with most detectors systems is large. In historic buildings, these problems are frequently met which limit the performance of detectors because it was designed for typical modern buildings having small rooms and low ceilings. The number of false alarms can be reduced by having detectors close spaced arranged in an intelligent self monitoring system linked to a microprocessor to check and reset system able to identify cable damage or the failure of a detector. Such systems are self-testing and will give maintenance advice. Escape routes should be protected by lobbies and free of obstructions and combustible material. Glazing in doors and screens must be fire resistant, but even so they present a hazard from radiation transmitting intolerable heat, so preventing escape on the other side of the fire barrier. Additional means of escape, such as external stairs, can disfigure historic buildings and so may prevent its beneficial use. Means of escape cannot be dealt with by a series of hard and fast rules, but guidance can be obtained from regulations relating to the number, position and widths of exist according to the maximum number of people likely to be in the building at any one time. Sometimes the number of person who may be present in historic buildings will be limited by the available means of escape. Signs indicating escape routes can also erode the architectural character of historic buildings, as such direction signs must be plainly visible. The constructions of walls, floors and ceilings of escape routes must be incombustible. To prevent the spread of smoke and fire into corridors and stairwells, self-closing fire stop doors must be provided. In historic buildings, fire stopping of intercommunicating voids must be meticulous. Any report on the fabric should be recommending considerable improvements such as fire stopping at floor levels or behind wall panelling. Roof insulation of glass fibre or rock wool can also gives fire protection, provided that it is not bonded with bitumen. (Fielden, 1996:241).

3.4.2 PASSIVE FIRE PROTECTION

Current perspective fire safety standards rely very heavily on passive fire protection, usually involving the enclosure of staircase and corridors leading to final escape points and the provision of fire doors across passageways. In addition to the intrusion that the additional doors and partitions can caused in an historic interior, upgrading the original historic features such as walls, floors, roofs and doors to standards of fire resistance intended for more modern buildings is less than ideal. The usual requirement is to ensure that all building elements of a defined fire compartment can resist the passage of fire and smoke for a minimum period of thirty minutes. If the main elements of the construction are masonry or similar then this standard can be achieved relatively easily, with only nominal enhancement to breaches in their integrity caused by pipe runs or cracks for example. However the main weak spots are the door openings where original doors are rarely able to satisfy the half hour requirement. In some cases it may be possible to upgrade their resistance using lining and seals with limited affect on their character and interest, but this may not be acceptable where particularly fine work is concerned. In other cases, there may not be any alternative to completely replace, if a passive approach to fire protection is employed. (Forrest, 1996:2). Once a flame has started in historic buildings, it will spread to any nearby combustible material and so build up until it is checked in one of three ways either by being deliberately extinguished, by running out of combustible material, or by being confined in a particular compartment with fireproof boundaries. Compartmentation, to be effective, must have a complete seal. It is preferable for each compartment to have at least two external doors to give access for fire fighting. Roof compartments can be devised with smoke vents operating by fusible links. Passive measures of fire protection, which do not rely on mechanical devices or human intervention, should be given a high priority in historic buildings as they are always on duty. Automatic devices such as drenchers and sprinklers can be useful, but it is wise to remember that sprinklers may cause damage to the contents of the building, so their use may be ruled out if the contents are historically valuable. In some cases after a fire, it has been remarkable that the fireman’s hose caused more damage than the fire itself. (Fielden, 1996:240). In choosing a system, one must consider capital costs, maintenance and running costs in comparison with the cost of equivalent protection from manpower. Generally, detection systems are the best solution because it is much cheaper and constantly alert.

3.5 THE PRINCIPLES OF FIRE RESISTANCE

Fire resistance according to The Aqua Group (1984:181), can be defined as “…the ability of an element of building construction to satisfy for a stated period of time some or all of the criteria specified in B.S. 476: Part 8: 1972 namely resistance to collapse, resistance to flame penetration and resistance to excessive temperature rise on the unexposed face”. Meanwhile Shields & Silcock (1987:170) defined fire resistance as “…the ability of an element of building construction to withstand the effects of fire for a specific period of time without loss of its fire separating and loadbearing functions”. According to Code of Practice Means of Escape in Case of Fire (1976:26), fire resistance can be defined as “…the construction so designated, including doors, has a minimum standard of fire resistance of not less than one half hour in accordance with the relevant Schedules of the current Building By-laws or which achieves such standard when tested in accordance with B.S. 476: Part 8: 1972”. Meanwhile referring to Taylor & Cooke (1978:14), fire resistance is “…a property currently measured in a B.S. 476: Part 8: 1972, furnace test, of a particular element of building construction (or building material) and is a measure of its ability to satisfy for a stated period in minutes until failure first occurs under any one of the three criteria”. The principles of fire resistance related to test methods and criteria for the fire resistance of elements of building construction lays down three specific criteria against which the fire resistance of any element can be measured. (Highfield, 1987:27). They are as follow:
a) Stability: Resistance to collapse or excessive deflection where for non-loadbearing constructions, failure occurs when the test specimen collapses and for loadbearing constructions, failure is related to collapse and the ability still to carry loads.
b) Integrity: Resistance to passage of flames and hot gases where failure occurs when cracks and other openings exist through which flame or hot gases can pass.
c) Insulation: Resistance to excessive temperature rise on unexposed face where failure occurs when the temperature of the unexposed (to fire) surface increases by more than 140C above the initial temperature, or by more than 180C, regardless of the initial temperature.
Thus the criteria attempt to relate the ability of a structural component to:
a) Endurance a fire without collapse.
b) Prevent the penetration of flame due to loss of integrity.
c) Resist the spread of fire by conduction through the component or by radiation from the face of the component not exposed to the fire.

The factors that determine the level of fire resistance of structural components are:
a) Purpose grouping.
b) Height of the building.
c) Floor area of the storey or compartment.
d) Cubic capacity of the building or compartment.
e) Location of the component, i.e. basement, ground or upper storey.

Since as shown earlier, the fire resistance capability required of components is derived from knowledge of fire severity likely to be experienced in use, it follows that the factors above somehow determine fire severity and consequently fire resistance. Although many shortcomings exist with regard to determining the fire resistance of components, it is an important factor, which contributes significantly to the attainment of fire safety in buildings. Fire resistance of components is an important performance criterion, e.g. of compartment walls and floors, roofs and doors, and therefor contributes to the attainment of life safety and property protection. (Shields & Silcock, 1987:171).

3.6 UPGRADING FIRE RESISTANCE IN HISTORIC BUILDINGS

Basically in upgrading fire resistance in historic buildings, the fire authority will sate its requirements in the draft schedules and it is at this point that the owner, architect (and fire consultant if appropriate) must decide if such requirements are reasonable or unduly onerous without affecting the special architectural and historical character of the buildings. A large number of the steps to be taken will deal with features of construction, internal planning, and in some cases furnishings. The authority giving helpful guidance and specifications for methods of upgrading supplies a number of standard forms as according to The Fire Precautions Act in Practice cited by Taylor & Cooke (1978:6). Also available are list of specialist contractors, manufacturers and suppliers of materials and equipment’s for the work of upgrading the fire resistance in historic buildings. The following are only broad guidelines, indicating some of the requirements for upgrading some of the elements i.e. walls, floors, roofs and doors in historic buildings. In practice, Davey, Heath, Hodges, Ketchin & Milne (1998:18) suggest that an architect should always be involved, working closely with the conservators, planning, building control and fire authorities in designing and upgrading the fire resistance.

3.6.1 WALLS

In the majority of historic buildings, the existing walls are normally masonry or brickwork, both of which have excellent fire resistance, and are therefor, unlikely to need upgrading. For example, an unplastered 100mm thick brick wall will give a fire resistance of two hours, which is more than adequate in virtually all circumstances. Masonry walls whatever their thickness, have an inherent fire resistance considerably in excess of the half hour or one hour normally required for low rise housing by current Building Regulations. Structural components within a wall, such as lintels, require an equal fire resistance. However, the possible effect of fire on the whole structure must always be considered. For example, structural components supporting a wall such as beams need to match the degree of fire resistance rating of the wall. Where a single dwelling is converted into a number of dwellings, the period of fire resistance required may need to be increased. In the case of internal wall linings, surface spread of flame and security of fixing are the main considerations. (BRE, 1990:67-84). It is quite possible, however, that some of the internal walls within an existing building represent more recent additions which may be of less substantial construction, such as blockwork or timber studding. Unplastered block walls 100mm thick will give a fire resistance of one hour and two hours respectively and are therefor, like brickwork and masonry, unlike to need upgrading for fire protection purposes. Fire resistance of separating and compartment walls is critical to safety of life in fire and limitation of damage in the event of fire to historic buildings. Soundly constructed masonry walls are usually able to provide fire resistance for periods longer than required by the Building Regulations. This inherent resistance to fire is however easily compromised if any unsealed holes or gaps are left through a wall. Walls generally rely for their stability upon other parts of the structure, such as timber floors or roofs, which are not so resistant to fire. Meanwhile loadbearing partitions will need to have fire resistance for a period of half and one and a half hours depending on the size of building and locations of partitions. Where partitions support a structural element with a designated fire resistance, then the partition is required to meet at least the same criterion. Adding plasterboard or additional thickness of wet plaster to existing construction most easily increases fire resistance. Current opinion is that lath and plaster will make a minimal contribution to fire resistance. (BRE, 1990:165-174). Many basic timber stud partitions however, only give half an hour fire resistance and therefor need upgrading if a higher standard is required. One of the simplest ways of upgrading such partitions is to nail an additional layer of 9.5mm plasterboard to each side, which will give a rating of one hour. If greater period of fire resistance is required, a wet plaster finish may be added, or thicker plasterboard used. Basically dry linings are suitable and popular alternative to wet plaster as means of upgrading wall surfaces in historic buildings. Providing a dry lining wall finish involves the fixing of gypsum plasterboard to the existing wall surface by one of a number of different techniques. Gypsum wallboard, plasterboard designed to receive direct decoration, is used, thereby it can eliminate the need for a wet skim coat of plaster. (Highfield, 1987:42-46). Basically there are three basic fixing techniques used to install dry linings, as follows:
a) Timber batten fixing: Timber battens are fixed vertically to existing wall 400-450mm centres. It is likely that the existing wall surfaces will be uneven, therefor all depressions are packed out with timber or fibreboard pieces in order to achieve correct alignment of the battens. The boards are then nailed to the battens vertically, with timber noggings inserted to support their horizontal edges. After the fixing and joints have been made good, the wallboards may be decorated directly by paintings, wallpapering or using any other suitable surface finish.
b) Metal channel fixing: As an alternative to fixing the plasterboard dry lining to timber battens, metal furring may be used. The system uses deep zinc-coated mild steel channels, which are bonded vertically to the existing wall using special gypsum adhesive. 200mm long dabs of the adhesive are applied to the wall at 450mm centres in vertical rows where each channel is to be fixed. When the adhesive has set, each wallboard is screwed to its three vertical channels. The fixings and joints are then made good and a suitable decorative finish applied to complete the upgrading of the wall. Details of the metal channel fixing dry lining system are shown in Figure 3.3 next page.
c) Direct adhesive fixing: Plasterboard dry lining can be bonded direct to the existing wall surfaces using special gypsum adhesive, thereby ruling out the need to install fixing battens and metal channel. A widely used proprietary system is the ‘Thistlebond’ dry lining system, which employs bitumen impregnated fibreboard alignment pads, and dabs of adhesive to secure wallboard to the existing surface. Firstly, the fibreboard alignment pads are fixed to wall in vertical rows 450mm apart using adhesive. After the pads have set, dabs of adhesive, which must be thick enough to stand proud of the pads, are applied to the background in vertical rows. Wallboard 900mm wide are then pressed on to the adhesive dabs and then temporarily secured to the pads with double headed nails. The joints between the wallboards can then be made good and the new surface finish applied.

3.6.2 FLOORS

The most common example of the need to upgrade existing timber floors occurs in the large numbers of historic buildings of traditional construction that were erected in the latter half of last century and the first part of this century. In the majority of historic buildings, the undersides of floors did not receive a ceiling finish and so they merely comprise floorboarding on timber joists left exposed on the underside. Such floors come nowhere regulations and they therefor require extensive upgrading. In addition, many such floors have plain edge boarding which is often found to have distorted over the years, leaving gaps, which, in the absence of a ceiling beneath, render the floor almost totally ineffective as a fire barrier. In most cases the fire resistance of the existing timber floors will need to be upgraded to half an hour or one hour, depending on the purpose group and size of the building. It is clear that the floors requiring upgrading will already have some form of ceiling finish like wood lath and plaster. (Highfield, 1987:27). Provided that such a floor has joists not less than 38mm wide and a ceiling of timber lath and plaster not less than 15mm thick. The existing ceiling will, therefor, already provide some degree of fire resistance and generally the upgrading treatment will not need to be as extensive as with floors comprising exposed joists. Normally the fire authority will require floors to have, or be upgraded to achieve, at least 30 minute fire resistance as referred to The Fire Precautions Act in Practice cited by Taylor & Cooke (1978:11). The fire resistance of a timber floor at historic buildings can be improved in several ways as follows:
a) Adding a fire-resisting layer beneath the existing joists or ceiling: There are numerous technique and material available for use in upgrading fire resistance of existing timber floors. The majority involve providing a new ceiling, where originally the joists were exposed, or an extra layer to the underside of the existing ceilings. In some cases it is also necessary to provide a protective layer on top of the existing floorboards or between the floor joists.
b) Filling the void between the existing floor surface and ceilings: In many conservation work, and particularly those involving buildings of architectural or historic interest, the existing ceilings may comprise ornate plasterwork which must be retained at all costs. The upgrading technique describes above will not, therefor, be suitable, since they would involve either removing or covering up the existing ceiling. The addition of a fire-resisting layer to the floor surface above the ceilings is generally inappropriate and inconvenient, and thus, the only remaining means of providing the required fire resistance is by filling the void between the floor surface and ornate ceilings with a suitable fire resisting material.

‘Tilcon’ foamed perlite is a site mixed material, produced from expanded perlite lightweight aggregate, a water based aerated foam, inorganic hydraulic binders and special additives, which can be pumped into the floor void to upgrade the fire resistance of existing timber floors. The material is produced on site using a suitable mixer and foam generator, and pumps or injected directly into the void after removing selected floorboards. Simple steel tongues are secured to the sides of the floor joists to provide additional retention of the material, which sets and cures to solid light grey honeycombed matrix. Official fire tests have shown that the insertion of ‘Tilcon’ foamed perlite into the floor cavity, to a depth of 175mm, will increase the fire resistance of such a floor to one hour. Foamed perlite can, of course, be used to upgrade any type of timber floor with a fillable void between the floor surface and ceilings, and the material can also be used for a range of other fire resisting applications. (Highfield, 1987:27-35). Other proprietary fire resisting materials are described below:
a) Supalux: A rigid laminar board material produced from a calcium silicate matrix reinforced with selected inorganic binders.
b) Vicuclad: A rigid monolithic board material produced from exfoliated vermiculite bonded with inorganic binders. Fixed to timber by nailing or screwing and to steel work by a special non combustible cement.
c) Limpet sprayed mineral fibre: A blend of selected man made mineral fibres and inorganic binders applied by spraying to form a homogeneous jointless coating.
d) Intumescent materials: These material are applied to surfaces in very thin coatings which, when exposed to fire, expand to form a meringue-like layer 50-75mm thick which insulates the material beneath from intense heat.

3.6.3 ROOFS

Roofs perform a number of functions, in relation to their fire performance they can perform two functions, to contain a fire or prevent its penetration from an external source and to ensure that the external coverings does not spread fire rapidly so that an adjoining roof might be in danger. (Langdon, 1972:96). In historic buildings, fire separation of the roof space between buildings is often incomplete, perforated or inadequately fire stopped at perimeters. Voids formed by boxed eaves may be continuous between roofs. If structural timbers run through firewall consider whether collapse through fire on one side would affect the integrity of the roof on the other side. Meanwhile it is common to find flat roof joists resting on separating or compartment walls with spaces between each joist. Alternatively, if beam filling is present then in many cases smaller gaps around joists and the underside of the roof deck may be found. If joists bear on the full width of a separating walls or if joists from two dwellings coincide on a wall this can constitute an unacceptable perforation. Subdivision of the ceiling void with cavity barriers is not needed in roof areas between fire division walls. Current Building Regulations require roofs to resist penetration of fire from the outside, prevent a fire spreading from one roof to another, and in the event of premature collapse, not to compromise the integrity of any compartment or separating wall, and during fire, not to destroy the integrity of any fire division wall with a prescribed fire resistance typically one hour. (BRE, 1990:121-136). The fire resistance of roofs at historic buildings can be improved in several ways. All pitched roofs should have ‘Masterboarding’ or ‘Supalux’ insulation board attached as a fire resistance. The board is fixed and made as airtight as possible by sealing all joints between it and the adjacent surfaces with good quality plaster. The sealing of these insulation board lining, and the rendering at the edges of the roof, must be maintained in good conditions. Meanwhile to ensure that the roof supports holds for the minimum amount of time in the event of fire, all timbers should be treated with fire resistance paint or solution in accordance with the manufacturer’s instructions. (Cunnington, 1984:240).

3.6.4 DOORS

Door assemblies at historic buildings are one of the most important elements of building construction affecting safety of life. Doors with their frames and furniture must have adequate fire resistance and smoke control properties, but this will be useless if they are left open and remain open in the event of fire. It is likely where historic buildings is improved or undergoes a change of use, that some of the existing external and internal doors will need either to be replaced or upgraded to comply with the requirements of the Building Regulations. Typical locations where fire doors are required include:
a) Doors separating maisonettes from spaces in common use.
b) Doors penetrating protecting structures i.e. fire resisting enclosures to corridors and stairwell.
c) Doors penetrating compartment walls i.e. fire resisting walls used to subdivide a building into compartments in order to restrict fire spread.

Fire doors will usually need to have a fire resistance of thirty minutes or sixty minutes, and most types of existing doors construction at historic buildings are capable of being upgraded to half an hour with relative ease. Fire test on timber doors suggested that the minimum thickness of solid timber panelling needed to survive a thirty minute test was in the range 20mm to 25mm. Most panelling is thinner and therefor needs reinforcement as required by The Fire Precautions Act in Practice cited by Taylor & Cooke (1978:7). However, upgrading an existing door to one hour standard is more difficult, and often produces a rather cumbersome result because of weight and thickness limitations. When one-hour fire doors are required, therefor, it is usually preferable to replace the existing doors rather than to attempt to upgrade them. But for doors that have an architectural or historical interest, this method is not appropriate because the door have to be retained at all cost. Therefor, the technique used to upgrade fire resistance of existing doors, wherever they are flush or panelled, are relatively simple and inexpensive. (Highfield, 1987:40-41). There are several technique and material available for use in upgrading the fire resistance of existing door leave and frame as described below:
a) Upgrading by facing: Usually existing doors will be of panel construction but framed, ledged and braced types are occasionally found. Panel doors not less than 45mm thick can be upgraded to give thirty minutes fire resistance using timber, plaster and asbestos insulation based board. For door less than 45mm thick, a greater contribution is required from the facing and an approved method is to use a 6mm asbestos insulating (not asbestos cement) board in place of plywood or hardboard. The porosity of asbestos insulation boards should be reduced using a watered down emulsion paint. These methods require the door panels to be infilled with insulating material in board form and the addition of a jointless facing on one or both sides of the door.
b) Upgrading using an intumescent system: The methods as described before involve the application of board facings to the door. But in older historic buildings, sometimes it may be undesirable on aesthetic grounds to obliterate the detailed form of finely worked doors. An alternative method used to upgrading the fire resistance is using ‘intumescent’ system formulated to give increased fire resistance applied to the risk side of the door. This will normally require existing paint to be completely removed from the panelled area so as not to provide a plane of weakness. During application of the ‘intumescent’ system which is applied to the door and sometimes the inside of the door stop, glass fibre tissue should be added into the first wet coat to cover each of the door panels, so improving their integrity in fire. Note that the coating is of a special nature so that cleaning or polishing agents are not applied and to guard against rough handling, inadvertent stripping or incompatible overpainting on redecoration should be avoid.
c) Upgrading using sandwich panelling: In historic buildings with finely worked doors which are finished with varnish or shellac, replacement or upgrading by boarding over or treating with the ‘intumescent’ system as described above may be inappropriate. It is quite common in such cases to remove the panels, slit them down the centre and then sandwich a layer of asbestos insulation board in between. This way the integrity of the panels, usually the weak spot in door construction, is improved with little visual loss. The mouldings may also need alteration. In other instances panels of wired glass have been fixed to the risk side of the door.
d) Upgrading using intumescent strips: For performance in excess of thirty minute fire resistance, additional protection around the door frame is usually necessary and the use of ‘intumescent’ strips have also been found necessary in fire tests. These strips have also been found necessary for timber doors in metal frames. But the use of intumescent paints is not recommended as their presence is not obvious and they are likely to be removed or have insufficient gap filling properties. Double swing doors should have a small clearance between leaves as is reasonably practical. Wherever possible, double doors, whether opening is in the same or opposite direction, it should have rebated meeting stiles with a minimum rebate of 25mm.
e) Upgrading using tight fit doorframes: A tight fit of doorframe is important if satisfactory integrity is to be achieved. Rubber buffer strips should therefore be removed. The door should lie flush against the stop when closed. For thirty minute fire resistance door, the gap between door edge and frame should not exceed 3mm, the upper two thirds of the door fit being most important as this is the region where smoke and hot gases appear as a result of positive pressure developed in fire. The depth of door stop/rebate should preferably be not less than 25mm for timber frames. To upgrade fire resistance at the door, timber stop may be planted for thirty-minute ratings and rebated from the frame for one-hour ratings.
f) Upgrading using rubber extrusions and brushes: Double swing doors used to control the flow of cool smoke rather than hot gases have synthetic rubber extrusions or nylon brushes let into the edges of the door leaves. A combination of fire resistance and smoke control can be achieved with intumescent strips and synthetic rubber extrusions or brushes as shown in Figure 3.15 next page. Basically intumescent materials will only expand when heated to a temperature between 150C and 200C. This can take up to ten minutes under furnace conditions. Taking into account the growth phase of the fire, it follows that a considerable amount of smoke may have passed by the ‘intumescent’ system before it swells to fill the gap between the door leaves and frames. (Taylor & Cooke, 1978:7-10).

CHAPTER 4 RESEARCH METHODOLOGY
4.1 INTRODUCTION

Fire resistance in historic building is a very important issue. It is to protect the life of its occupants, building fabric and its contents. Therefore the aim of this research is to evaluate the works that have been done in upgrading fire resistance in historic buildings. Meanwhile the findings is to suggest the best technique and method of upgrading fire resistance at building elements such as walls, floors, roofs and doors.

4.2 CHOICE OF METHODOLOGY

A questionnaire has been used to determine information regarding upgrading of fire resistance in historic buildings. It seems as an obvious way to evaluate the importance and the works that has been done by owner of the historic buildings. Questionnaire method is considered to be the best method of collecting the data required for this research due to a large number of historic buildings and located at various locations in Portsmouth. Besides that the advantage of this method is it can enable the researcher to get different opinion and respond from the owner of the historic buildings at their own pace and idea.

4.3 QUESTIONNAIRE DESIGN

To collect the quantitative data from the owner of historic buildings, structured questionnaire had been used. It contains a series of open and closed questions where the first section is open questions that require the owner of historic buildings or the person who is responsible to the building to answer the questions given. The question in this first section is more on getting the information about the building and fire precaution that has been taken at the building. The second section is closed questions where it was presented in form of a list of various technique and method available on upgrading fire resistance according to the building elements, which is walls, floors, roofs and doors. Basically the owner have to select the technique and method that has been used at their building and/or suggest what is the appropriate choice that he think suitable to be applied at their building. Various choices of answer are provided at each technique and method and what the owner has to do is tick the appropriate box that they agreed with. An opportunity was provided in the questionnaire to give the owner chances to give alternative technique and method that are not mentioned in the questionnaire. A quantitative methodology was chosen to analyse the data collected and performs it in a statistical or graphical format. This methodology is easy to analyse and understood. It was considered that the two section in the structured questionnaire used would be more objectives because open questions will give more information about the building and closed question will give the exact data to be analyse in the research so that the result of the findings will be more accurate.

4.4 SURVEY SAMPLE

The target for this research was to the owner of historic buildings in Portsmouth and surroundings area. The reason for choosing this group of people is because they know their building better and can give the correct answer directly. In this research, 50 structured questionnaire has been distributed to the owner of historic buildings with different type and category of buildings. To clarify the historic buildings it is easier to take listed buildings as the sample. A listed building is one that has been included on the Secretary of States list of buildings of architectural or historic interest. The list of the listed buildings is taken from the Register of Listed Buildings and Scheduled Ancient Monuments in Portsmouth prepared by Portsmouth City Council as of 1999. The current list for Portsmouth is describes over 600 buildings where Grade I are buildings of exceptional architectural or historic interest, Grade II* are particularly important buildings of more than special interest and Grade II are buildings of special architectural interest which warrant every effort being made to preserve them. Referring to the list, in Portsmouth, most of the Georgian period buildings are listed and virtually all the building is built before 1700. Between 1840 and 1914 or during the Victorian and Edwardian periods, only buildings of definite quality are listed. Lastly the 20th Century buildings are considered important and listed only if they are of exceptional quality. Therefor a few buildings at each period has been chosen as the survey samples ranging from Grade I to Grade II, meanwhile the type of buildings selected is variable from residential house to public buildings.

4.5 QUESTIONNAIRE DISTRIBUTION

In this research, the entire questionnaire was distributed by hand to the selected historic buildings as described before. The owner of the building is then responsible to return the questionnaire by using the stamped enveloped provided. The researcher probably can get back all the questionnaires excellently. Besides that the owner can contact the researcher to collect the questionnaire. This alternative method was given to make the owner feel not burden with the questionnaire. Otherwise it is impossible to get back all the questionnaire from the owner. It was viewed that the selection of the samples would give a quality feedback because the questionnaire was distributed to the right person and option was given to the owner to return the questionnaire.

4.6 LIMITATIONS OF THE SURVEY

In this research, the questionnaire provides the owner of historic buildings choices of all possible answers to the questions. At all times it was attempted to avoid the use of leading questions. However it is recognised that a quantitative methodology is restrictive, inflexible and can limit the discovery of questionnaire. There is a danger that an important influencing factor may have been excluded or that the owner is directed in his reply to this damaging validity. To increase the validity of the results it would have been useful to test the data further using other methods. There is no guarantee that the researcher will get a good response to the questionnaire. Owner of historic buildings may choose not to answer to the several questions because they may not interest or not sure to answer the questions. Additionally, we cannot expect owner to answer the required question fully. For example in section two that required the owner to have knowledge in construction related to upgrading the fire resistance at building elements. It could make the owner not to give responds to the questionnaire if they didn’t have the knowledge about the subject matter. The questionnaire is basically dealt with the technique and method used by the owner of historic buildings on upgrading fire resistance at their building. Most of the question would asked about the technique and method of upgrading fire resistance in four building elements, which is walls, floors, roofs and doors. For example, section two of the questionnaire requires the owner to tick the technique or method that they have used or think suitable to be used at their buildings for every element. This mean that the owner already has done the upgrading technique and method or agrees with the technique and method provided. By this way, it helps to give a quality evidence for the use in the research. It has been useful to investigate further responses to many of these questions, through either follow up interview or focus on case study. This would have enabled a greater result to be achieved. It is important to maintain the validity of the research. The method used was the best method to get result and test the interaction of a large number of respondents. It was the best method to use in the limited time period given. The data collected will affected the result to helps owners of historic buildings in upgrading fire resistance at their buildings.

CHAPTER 5 ANALYSIS OF DATA AND FINDINGS
5.1 INTRODUCTION

This chapter establishes the results of chapter 3 (Literature Review) and the questionnaire mailed to the selected historic buildings in Portsmouth. For the data collection, five pages of questionnaire titled ‘Survey on Upgrading Fire Resistance in Historic Buildings’ was distributed to 50 historic buildings. An approximately 50 percent of the questionnaire were returned and analysed. The questionnaire consists of two sections. Section 1 focus on the buildings and fire background, and Section 2 focus on the technique and method of upgrading the standard of fire resistance in historic buildings. The results are discuss and analysed to reveal the building owners perception meanwhile the aim of this chapter is to achieve the three objectives of the dissertation.

5.2 ANALYSIS OF DATA

The result of the data collected from the questionnaire is tabulated and summarised in tables and figures as shown at next pages. The data is based on the questions asked from Section 1 question no. 1 to 9.

QUESTION NO 1: Name and address of the building.
From the result, we can conclude that most of the buildings surveyed is located in Old Portsmouth (33%), followed by Portsea (28%), Southsea (20%), Eastney (12%) and lastly Fratton (8%).

QUESTION NO 2: Year of built.
From the result, we can conclude that most of the buildings is built in 19th Century (44%), followed by 18th Century (24%), 17th Century (16%), 16th Century (12%) and lastly 20th Century (4%).

QUESTION NO 3: Type of building.
NUMBER
From the result, we can conclude that most of the type of buildings surveyed is Terraced House (40%), followed by Semi Detached (28%), Villa (12%), Cathedral (4%), Museum (4%), Theatre (4%), School (4%) and lastly Shop (4%).

QUESTION NO 4: Listed category.
From the result, we can conclude that most of the buildings is listed as Grade II (80%), followed by Grade II* (20%) and none Grade I (0%).

QUESTION NO 5: Owner.
From the result, we can conclude that most of the buildings is owned by Private (80%), followed by HCC (12%) and lastly PCC (8%).

QUESTION NO 6: Do you think that fire resistance is important to historic buildings?
From the result, we can conclude that most of the respondents agreed that fire resistance is important to historic buildings (100%) and none disagreed (0%).

QUESTION NO 7: Have you upgraded the fire resistance at your building?
From the result, we can conclude that most of the buildings haven’t been upgraded the fire resistance (68%) and the rest that have upgraded (32%).

QUESTION NO 8: When did you upgrade the fire resistance?
From the result, we can conclude that most of the buildings has upgraded the fire resistance in 1980s (63%), followed by 1990s (25%) and lastly in 1970s (12%).

QUESTION NO 9: Did the building have any experience of fire?
From the result, we can conclude that most of the buildings didn’t have any experience of fire (100%) and none have (0%).

Meanwhile the result of the data collected from the questionnaire based on the questions asked from Section 2 question no. 1 to 4 is tabulated and summarised in tables and figures as shown below.

QUESTION NO 1.1: Type of materials (Internal Wall and Partitions).
From the result, we can conclude that most of the materials used as internal wall and partitions is timber (76%), followed by masonry (16%), brickwork (8%) and lastly none in blockwork (0%).

QUESTION NO 1.2: Have you upgraded the fire resistance at wall elements. If ‘Yes’ please specify the methods.
From the result, we can conclude that most of the wall elements haven’t been upgraded (88%) and the rest (12%) have. The method used is plasterboard.

QUESTION NO 1.3: If ‘No’ please choose one of the suitable method of upgrading fire resistance.
From the result, we can conclude that most of the respondent choose direct adhesive fixing (60%), followed by plasterboard (20%), wet plaster finish (12%), timber batten fixing (8%) and lastly none metal channel fixing (0%).

QUESTION NO 2.1: Type of materials (Upper Floors).
From the result, we can conclude that most of the materials used as upper floors is timber (100%) and none in concrete (0%).

QUESTION NO 2.2: Have you upgraded the fire resistance at floor elements. If ‘Yes’ please specify the methods.
From the result, we can conclude that most of the floor elements haven’t been upgrade (76%) and the rest (24%) have. The method used is by fixing the fire resisting material at the void between floor and ceilings.

QUESTION NO 2.3: If ‘No’ please choose one of the suitable method of upgrading fire resistance.
From the result, we can conclude that most of the respondent choose the method of fixing fire resisting materials (84%) and the rest choose the method of adding fire resisting layer (16%).

QUESTION NO 3.1: Type of materials (Roofs Structure).
From the result, we can conclude that most of the materials used as roof structure is timber (100%) and none in concrete (0%).

QUESTION NO 3.2: Have you upgraded the fire resistance at roof structures. If ‘Yes’ please specify the methods.
From the result, we can conclude that most of the roof structures haven’t been upgraded (84%) and the rest (16%) have. The method used is by using insulation board.

QUESTION NO 3.3: If ‘No’ please choose one of the suitable method of upgrading fire resistance.
From the result, we can conclude that most of the respondent choose the method using insulation board (88%) and the rest choose the method of using timber treated with fire resistance paint (12%).

QUESTION NO 4.1: Type of materials (Internal Doors).
From the result, we can conclude that most of the materials used as internal doors is timber (100%) and none in steel (0%).

QUESTION NO 4.2: Have you upgraded the fire resistance at door elements. If ‘Yes’ please specify the methods. From the result, we can conclude that most of the door elements haven’t been upgraded (80%) and the rest (20%) have. The method used is by using intumescent system and strips.

QUESTION NO 4.3.1: If ‘No’ please choose one of the suitable method of upgrading fire resistance (Door panel).
From the result, we can conclude that most of the respondent choose the method using sandwich panelling between door surface (72%), followed by intumescent system (20%) and lastly the method of using insulation board at the facing (8%).

QUESTION NO 4.3.2: If ‘No’ please choose one of the suitable method of upgrading fire resistance (Door frame).
From the result, we can conclude that most of the respondent choose the method using rubber extrusion and brushes (48%), followed by intumescent strips (32%) and lastly the method using tight fit door frame (20%).

5.3 FINDINGS

Based on the analysis of data as shown in previous pages, the findings of the research is described and summarised as follow to fulfil the three objectives of the research.

Findings No. 1 : Important of fire resistance to historic buildings.
Referring to the research work from literature review and supported by the previous analysis of data, we can conclude that fire resistance is important to historic buildings because it can prevent the outbreak of fire, minimise the effects of fire by preventing it from spreading and enable the fire to be fought efficiently with minimum damage to its valuable contents.

Findings No. 2: Upgrade fire resistance at historic buildings.
Referring to the research work from literature review and supported by the previous analysis of data, we can conclude that most historic buildings in Portsmouth haven’t upgraded the fire resistance.

Findings No. 3: Technique and method of upgrading fire resistance at walls, floors, roofs and doors.
Referring to the research work from literature review and supported by the previous analysis of data, we can conclude that the most suitable method of upgrading fire resistance to building elements without effecting the features of the historic buildings is as follow:
a) For internal walls and partitions, the best choice is by using direct adhesive fixing as dry lining, followed by plasterboard, wet plaster finish, timber batten fixing and lastly metal channel fixing as dry lining.
b) For upper floors, the best solution is by fixing the fire resisting materials at the void between the floor and ceilings compared by adding fire resisting layer beneath the joist or ceilings.
c) For roof structure, the best techniques is by using insulation board rather than using timber treated with fire resistance paint.
d) For internal doors, the best method for upgrading the door panel is by using sandwich panelling between door surface, followed by intumescent system and lastly insulation board at the facing. e) For internal doors, the best method for upgrading the door frame is by using rubber extrusions and brushes, followed by intumescent strips and lastly tight fit door frame.

CHAPTER 6 CONCLUSION AND RECOMMENDATIONS
6.1 CONCLUSION

No building is free from the threat of fire whether it is old or new. A designer however, can ensure that only limited damage will result if fire breaks out by reducing the overall fire resistance. If a fire grows to a sufficient size within a compartment in historic buildings, then it may breach the bounding walls or floor and roofs and spread to other parts of the building through doors. In order to prevent this from occurring, or to delay its occurrence sufficiently to allow occupants to escape from other parts of the building, bounding elements are designed to have a given level of fire resistance at buildings elements such as walls, floors, roofs and doors. Fire resistance construction may be described as construction that continues to fulfil its function during the course of a fire, and where walls, floors, roofs and doors are involved in preventing the transmission of fire beyond the boundaries. It must not be confused with non-combustible construction, which may or may not have the requisite degree of fire resistance in a given set of circumstances. It is however, frequently necessary to resort to largely non-combustible construction in order to achieve substantial fire endurance i.e. a long fire resistance time period. The fire resistance of building elements is universally defined in terms of the length of time it will meet certain requirements when exposed in a test furnace. For historic buildings, the fire resistance requirements are in turn related to the fire load within it and therefore a bit high. Fire resistance also relates to the ability of the elements to retain its integrity and loadbearing capacity, and to provide sufficient insulation. Some of the existing building elements at historic buildings has already have the fire resistance ability such as brickwalls that have half to one hour fire resistance and solid timber panel door that have at least half hour of fire resistance. But some of the element didn’t have the element of fire resistance as required by Building Regulations and Fire Precaution Act and therefor need to be upgraded. In general, real fires do not follow the standard time/temperature requirement, and simple perspective requirements based upon a minimum time to failure in the furnace test. Nowadays, there are various techniques and methods of upgrading fire resistance in historic buildings. Referring to the result of the research, we can conclude that fire resistance is very important to historic buildings but unfortunately most historic buildings has never been upgrade their fire resistance. Therefore, it is suggest that the buildings should upgrade their fire resistance by using one of the following methods. Direct adhesive fixing at walls, fixing method at floors, insulating board at roofs, sandwich panelling at door frame and lastly rubber extrusions and brushes at door frames. The selection of these techniques and methods is agreed to be the best method of upgrading the fire resistance at historic buildings because it doesn’t affect the changes of appearance at the building elements and less damage is done to the structure. Meanwhile the use of fire resistance paints, varnishes and polishes should be able to provide a layer of coating which is neither flammable in itself or likely to propagate fire, irrespective of the nature of the substrate and to protect combustible base materials such as wood against the effects of fire by thermal insulation in the first stage of a fire and then by smothering flames produced by gases. Although no surface treatment can make a substrate absolutely incombustible, it can make a useful contribution by delaying the spread of fire, for when fire breaks out in historic buildings where the nature of the interior surfaces may determine the time available for the occupants to escape. Finishes like wax polishes on floors can melt and produce running fire, which can be dangerous in public building and therefor floors at escape routes should have incombustible finishes and good protection against fire. The key to a successful solution is the fire risk assessment. The assessment also needs to consider any owner requirements that may have an affect on upgrading the fire resistance. For example, where a stately house or a museum is concerned the need to salvage artefacts could well represent an important factor in the upgrading works at the buildings. Recent report commissioned by the Government to enquire into major fires in historic buildings has placed strong emphasis on the requirement and importance of building elements. The fire plan design philosophy should reflect this emphasis by identifying a solution that utilises existing building features. The acceptability of design solutions which make full use of the existing fabric with the minimum alterations will ultimately depend on the length of time taken to evacuate the building safely, under fire conditions, and assuming worst case occupations conditions.

6.2 RECOMMENDATIONS

Owners of historic buildings are recommended to seek specialist advice before undertaking any work on upgrading the fire resistance their building. Further more, local authority conservation officers architect, fire engineers and other interested responsible bodies like English Heritage must be consulted before any work is carried out. Because of architectural and historical considerations, work to upgrade the fire resistance at historic buildings needs to be carried out with sensitivity so as not to damage the building’s historic interest. There are often alternative ways of improving the fire resistance where it is necessary to do so without making features and structural changes to the building or by keeping changes to an absolute minimum as described in previous chapter. In some small historic buildings for example, which contains a staircase within one single space, with all rooms opening directly off it, further compartmentalisations may be unnecessary. By upgrading the fire resistance at walls and doors to provide half hour fire protection can be avoided by introducing an air pressurisation system. In the event of fire occurring in one of the rooms, the system is activated, rapidly pressurising the escape route and forcing smoke to leave the building through vents introduced in the rooms. However the system has limited application as it can only be used where the staircase is self contained, and due to the problems associated with accommodating the large amount of plant required. Therefore all changes must comply with Building Regulations and Fire Precaution Act. It is recommended that the owner of historic buildings to check the fire risk assessment that can help in deciding what might need to be done to the historic buildings. Basically by upgrading the fire resistance at building elements such as walls, floors, roofs and doors, it can reduce the danger of fire spread through these elements. Meanwhile in term of fire resistance and life safety, the fire resistance requirements so far discussed have all been related to the duration of the fire. Evacuation of the building would then be the only feature to be considered. Suitable fire resistance recommendations might be that all building elements should comply with structural requirements for one hour and the temperature requirements for thirty minutes. It is also recommended that historic buildings should install automatic fire detection in areas presenting a high fire risk where by doing so, it could reduce the need for fire resisting construction. Such an approach must be given with the most careful thought. It can only be valid where adequate warning can be expected from detection and alarm systems, and where it is known that the response to an alarm will be the complete evacuation of the building. Special provision may be necessary where there are infant, senile or restrained occupants in the historic buildings. It is hope that in the next decade will be a period of major changes as perspective approach lead to more performance or ‘engineered’ means of upgrading fire resistance in historic buildings. It is essential that the UK remain at the forefront of developments to exploit the freedoms, which the regulations already provide in principle.

LIST OF REFERENCES

1. Withers, M. (1975). Fire Protection of Panelled Doors. Bath Preservation Trust, Bath.
2. Parnell, A. & Ashford, D. (1990). Fire Safety in Historic Buildings. Part I, Technical Phamplet 61. Society for the Preservation of Ancient Buildings, London.
3. NFPA (National Fire Protection Association) (1995). Recommended Practice for the Protection of Museums and Museums Collection. National Fire Protection Association, Massachusetts.
4. Kidd, S. (1990). Heritage Under Fire. Fire Protection Association, London.
5. FPA (Fire Protection Association) (1990). Fire and Historic Buildings. Fire Protection Association, London.
6. FPA (Fire Protection Association) (1981). Fire and the Architect: Fire Protection Design Guide. Fire Protection Association, London.
7. DOE (Department of Environment) (1990). Standard Fire Precautions for Contractors. HMSO, London.
8. DOE (Department of Environment) (1991). Guidance for the Design of Government Buildings. HMSO, London.
9. BRE (Building Research Establishment) (1987). Fire Doors. Digest 320. HMSO, London.
10. Jones, B. (1986). Protecting Historic Architecture and Museum Collections from Natural Disasters. Butterworth, London.
11. Butcher, E.G. & Parnell, A.C. (1983). Designing for Fire Safety. John Wiley, Chichester.
12. HO (Home Office) (1993). Fire Statistics United Kingdom 1991. HMSO, London.
13. MOW (Ministry of Works) (1946). Fire Grading of Buildings. HMSO, London.
14. BSI (British Standards Institution) (1987). Glossary of Terms Associated with Fire. BS 4422. British Standards Institution, London.
15. BSI (British Standards Institution) (1972). Fire Tests on Building Materials and Structures. BS 476. British Standards Institution, London.
16. Davey, N. & Ashton, L.A. (1953). Investigations on Building Fires. HMSO, London.
17. Pitt, P.H. (1987). Guide to Building Control by Local Acts. Architectural Press, London.
18. Chitty, T.B., Nicholson, D. & Malhotra, H.L. (1970). Tests on Roofs Constructions Subject to External Fire. HMSO, London.
19. Morris, W.A., Read, R.E.H. & Cooke, G.M.E. (1988). Guidelines for the Construction of Fire Resisting Structural Elements. BRE Publications, Watford.

LIST OF BIBLIOGRAPHY

1. Allen, B. (1990). Fire and Building Regulation. HMSO, London.
2. BRE (Building Research Establishment) (1990). Assessing Traditional Housing for Rehabilitation. BRE Publications, Watford.
3. Cunnington, P. (1984). Care for Old Houses. Prism Alpha, Dorset.
4. Davey, A., Heath, B., Hodges, D., Ketchin, M. & Milne, R. (1988). The Care and Conservation of Georgian Houses. Butterworth Architecture, London.
5. Derek, J. (1986). Fire Prevention Handbook. Butterworth & Co. Ltd., London.
6. DOE (Department of Environment) (1992). The Building Regulations 1991. HMSO, London.
7. Fielden, B.M. (1996). Conservation of Historic Buildings. Butterworth Architecture, Oxford.
8. FPA (Fire Protection Association) (1954). Fire Protection of Country Houses. Fire Offices’ Committee, London.
9. FSE (Fire Safety Engineering) (1995). A Research for the Fire Safety Engineering Design of Buildings. BRE Publications, Watford.
10. GLC (Greater London Council) (1976). Code of Practice Means of Escape in Case of Fire. Greater London Council, London.
11. Highfield, D. (1987). Rehabilitation and Re-use of Old Buildings. E & FN Spon, London.
12. HOFD (Home Office Fire Department) (1977). Manual of Firemanship: Fire Protection of Buildings (Book 9). HMSO, London.
13. Jagger, M. (1979). Hampshire’s Heritage and a Policy for its Future. Hampshire County Planning Department, Hampshire.
14. Langdon-Thomas, G.J. (1972). Fire Safety in Buildings: Principles & Practice. A & C Black Limited, London.
15. Newbold, P.S. (1999). Register of Listed Buildings and Scheduled Ancient Monuments in Portsmouth. Portsmouth City Council, Portsmouth.
16. Read, R.E.H. & Morris, W.A. (1983). Aspects of Fire Precautions in Buildings. BRE Publications, Watford.
17. Shields, T.J. & Silcock, G.W.H. (1987). Buildings and Fire. Longman Scientific & Technical, New York.
18. Taylor, J. & Cooke, G. (1978). The Fire Precautions Act in Practice. The Architectural Press, London.
19. The Aqua Group (1984). Fire and Building. Granada Publishing Ltd., London.

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