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Brandspridning och brandförlopp i tät småhusbebyggelse : fire spread and fire development in low-rise residential building areas

Ondrus, Julia (1988) In LUTVDG/TVBB--3043--SE 3043.
Abstract
This investigation makes a survey of the spread of fire and the fire development in low-rise residential building areas through obtaining the literal knowledge of factors having influence

on a fire in one burning building and fire spread between buildings within a group of single-family houses. The purpose of the investigation was, on basis of the knowledge, to propose improved measures and the character and extent of continuing research work. The investigation shows that the statistical value on occurred fires in low-rise residential buildings has not increased very strongly in spite of the fact that the number of building areas with low-rise residential houses and with narrow

streets had increased. According to... (More)
This investigation makes a survey of the spread of fire and the fire development in low-rise residential building areas through obtaining the literal knowledge of factors having influence

on a fire in one burning building and fire spread between buildings within a group of single-family houses. The purpose of the investigation was, on basis of the knowledge, to propose improved measures and the character and extent of continuing research work. The investigation shows that the statistical value on occurred fires in low-rise residential buildings has not increased very strongly in spite of the fact that the number of building areas with low-rise residential houses and with narrow

streets had increased. According to statistical figures from 1985 there are about 1.8 million dwellings in low-rise residential buildings in Sweden. The number of fire damages in low-rise residential buildings announced to insurance companies were in 1975 4 100 and 4 700 in 1985 respectively. The comparative figure for fire damages in other types of dwellings were 9 000 in both 1975 and 1985. The total of damaged buildings, with the quota limit 500 000 Swedish krowns and more. had between 1975 and 1986 cost less than 12% of all compensation costs each year. The fires in low-rise residential buildings. which results in fire spread over a bigger part of building areas are unusual in Sweden. Fires in dwellings in low-rise residential buildings will very often be extinguished in its beginning because of the alarm coming early and the time of action being short. These factors are the positive consequences of the more closed building areas, which compensates for the increased fire spread hazards as a result of the concentration of houses. However, there are some problems in addition to the concentration of houses. The problems connected with fires in low-rise residential building areas in Sweden are principally: the fire spread in houses in row, especially where the attics are built together with imperfections in/or absences of separating walls. Another very usual effect to fire spread in houses built together - houses in row - are continuous combustible eaves with a ventilation air gap for air exchange into the attics. Through these air gaps the smoke from the compartment fire can press into the attic space. This type of structure imperfections are stated as a reason to fire spread in many reports from other countries, too. Founding the optimum design of eaves, for example through come experiments. would be of use even for eaves on other buildings than single-family houses. because the same risk of fire spread

through the attic spaces exists there. The structure of low-rise residential buildings. the design of these buildings areas and the number of fie brigades are regulated in the Swedish Building Code, SBN 80. The result of this code is that the influence of one burning house to the neighbour is concentrated in the flames coming out from the windows. The influence of radiation from the window openings and the flames above the windows is probably the most dominating factor for all the Swedish structures of low-rise residential buildings. The radiation from the window openings and the flames above windows is in its turn dependent on the contents of the room burning - the materials in the furniture and on the room surfaces. The contents of the burning room determines the fire intensity until the pre-flashover, before the extinction started. That factor has an influence on the size and character of facade flames. A changing in composition of the traditional furniture to the modern furniture of synthetic materials gives a more intensive fire development. It would be desirable to develop. on this basis, a new general and distinguished design of building separation. A fire development on the basis of a modern furniture could even be a basis of an eventual risk analysis for planing of low-rise residential building areas in the future. In Japan they are working with the modelling and developing of computer codes for risk analysis in low-rise residential building areas. A Swedish mode1 of risk analysis after the Japanese model, probably requires some experiments defining the heat flow and burning rate from typical Swedish houses. Even older theoretical or experimental results can be used. Possibilities of studying the fire spread by experiments in mode1 scale are limited. The proposal for measures and research achievements in the future are founded on the knowledge conducted in this investigation and presented in this report. Chapter 1 describes the structure, size, design and development of the Swedish low-rise residential building areas. In Chapter 2 a synthesis of statistical data on occurred fires in single-family houses and houses in row are presented and compared with some figures from other countries. Chapter 3, which is the most comprehensive one, illustrates the fire development with the flame size and flame height in single-houses, mechanism of fire spread and propagation of fire in houses built together and between neighbouring houses. A lot of information has been collected through interviews with active firefighters and those who work for the prevention of fire. Case studies from other countries, the theoretical and experimental investigations from several countries show that fire spread mechanisms have relevance. The Swedish regulations concerning building fire safety in single-

family houses. protection against the spread of fire between buildings, requirements of roof protecting and fire fighting facilities are summarized and completed with come comments. Water support and water consumption in low-rise residential building areas are also described in this chapter. From the literature from several countries are taken information concerning fire in large building areas, conflagration as it is called, the reasons for and development of this. They are presented in Chapter 4. Climate and wind circumstances in Sweden, especially in building areas and with regard to fire spread are described in Chapter 5. Chapter 6 contains the mode1 laws and scaling models necessary for mode1 scale experiments. In the last chapter the requirements of continuing research work. come out from this investigation, are presented. (Less)
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publishing date
type
Book/Report
publication status
published
subject
in
LUTVDG/TVBB--3043--SE
volume
3043
pages
137 pages
publisher
Department of Fire Safety Engineering and Systems Safety, Lund University
ISSN
0284-933X
language
Swedish
LU publication?
no
id
486e82b9-8b03-4a5c-9987-1322ca6c9706 (old id 1267839)
date added to LUP
2008-11-17 13:47:36
date last changed
2016-06-29 09:16:23
@techreport{486e82b9-8b03-4a5c-9987-1322ca6c9706,
  abstract     = {This investigation makes a survey of the spread of fire and the fire development in low-rise residential building areas through obtaining the literal knowledge of factors having influence<br/><br>
on a fire in one burning building and fire spread between buildings within a group of single-family houses. The purpose of the investigation was, on basis of the knowledge, to propose improved measures and the character and extent of continuing research work. The investigation shows that the statistical value on occurred fires in low-rise residential buildings has not increased very strongly in spite of the fact that the number of building areas with low-rise residential houses and with narrow<br/><br>
streets had increased. According to statistical figures from 1985 there are about 1.8 million dwellings in low-rise residential buildings in Sweden. The number of fire damages in low-rise residential buildings announced to insurance companies were in 1975 4 100 and 4 700 in 1985 respectively. The comparative figure for fire damages in other types of dwellings were 9 000 in both 1975 and 1985. The total of damaged buildings, with the quota limit 500 000 Swedish krowns and more. had between 1975 and 1986 cost less than 12% of all compensation costs each year. The fires in low-rise residential buildings. which results in fire spread over a bigger part of building areas are unusual in Sweden. Fires in dwellings in low-rise residential buildings will very often be extinguished in its beginning because of the alarm coming early and the time of action being short. These factors are the positive consequences of the more closed building areas, which compensates for the increased fire spread hazards as a result of the concentration of houses. However, there are some problems in addition to the concentration of houses. The problems connected with fires in low-rise residential building areas in Sweden are principally: the fire spread in houses in row, especially where the attics are built together with imperfections in/or absences of separating walls. Another very usual effect to fire spread in houses built together - houses in row - are continuous combustible eaves with a ventilation air gap for air exchange into the attics. Through these air gaps the smoke from the compartment fire can press into the attic space. This type of structure imperfections are stated as a reason to fire spread in many reports from other countries, too. Founding the optimum design of eaves, for example through come experiments. would be of use even for eaves on other buildings than single-family houses. because the same risk of fire spread<br/><br>
through the attic spaces exists there. The structure of low-rise residential buildings. the design of these buildings areas and the number of fie brigades are regulated in the Swedish Building Code, SBN 80. The result of this code is that the influence of one burning house to the neighbour is concentrated in the flames coming out from the windows. The influence of radiation from the window openings and the flames above the windows is probably the most dominating factor for all the Swedish structures of low-rise residential buildings. The radiation from the window openings and the flames above windows is in its turn dependent on the contents of the room burning - the materials in the furniture and on the room surfaces. The contents of the burning room determines the fire intensity until the pre-flashover, before the extinction started. That factor has an influence on the size and character of facade flames. A changing in composition of the traditional furniture to the modern furniture of synthetic materials gives a more intensive fire development. It would be desirable to develop. on this basis, a new general and distinguished design of building separation. A fire development on the basis of a modern furniture could even be a basis of an eventual risk analysis for planing of low-rise residential building areas in the future. In Japan they are working with the modelling and developing of computer codes for risk analysis in low-rise residential building areas. A Swedish mode1 of risk analysis after the Japanese model, probably requires some experiments defining the heat flow and burning rate from typical Swedish houses. Even older theoretical or experimental results can be used. Possibilities of studying the fire spread by experiments in mode1 scale are limited. The proposal for measures and research achievements in the future are founded on the knowledge conducted in this investigation and presented in this report. Chapter 1 describes the structure, size, design and development of the Swedish low-rise residential building areas. In Chapter 2 a synthesis of statistical data on occurred fires in single-family houses and houses in row are presented and compared with some figures from other countries. Chapter 3, which is the most comprehensive one, illustrates the fire development with the flame size and flame height in single-houses, mechanism of fire spread and propagation of fire in houses built together and between neighbouring houses. A lot of information has been collected through interviews with active firefighters and those who work for the prevention of fire. Case studies from other countries, the theoretical and experimental investigations from several countries show that fire spread mechanisms have relevance. The Swedish regulations concerning building fire safety in single-<br/><br>
family houses. protection against the spread of fire between buildings, requirements of roof protecting and fire fighting facilities are summarized and completed with come comments. Water support and water consumption in low-rise residential building areas are also described in this chapter. From the literature from several countries are taken information concerning fire in large building areas, conflagration as it is called, the reasons for and development of this. They are presented in Chapter 4. Climate and wind circumstances in Sweden, especially in building areas and with regard to fire spread are described in Chapter 5. Chapter 6 contains the mode1 laws and scaling models necessary for mode1 scale experiments. In the last chapter the requirements of continuing research work. come out from this investigation, are presented.},
  author       = {Ondrus, Julia},
  institution  = {Department of Fire Safety Engineering and Systems Safety, Lund University},
  issn         = {0284-933X},
  language     = {swe},
  pages        = {137},
  series       = {LUTVDG/TVBB--3043--SE},
  title        = {Brandspridning och brandförlopp i tät småhusbebyggelse : fire spread and fire development in low-rise residential building areas},
  volume       = {3043},
  year         = {1988},
}