Fire Technology

, Volume 53, Issue 3, pp 1201–1232 | Cite as

Experimental Characterisation of the Fire Behaviour of Thermal Insulation Materials for a Performance-Based Design Methodology

  • Juan P. Hidalgo
  • José L. Torero
  • Stephen Welch


A novel performance-based methodology for the quantitative fire safe design of building assemblies including insulation materials has recently been proposed. This approach is based on the definition of suitable thermal barriers in order to control the fire hazards imposed by the insulation. Under this framework, the concept of “critical temperature” has been used to define an initiating failure criterion for the insulation, so as to ensure there will be no significant contribution to the fire nor generation of hazardous gas effluents. This paper proposes a methodology to evaluate this “critical temperature” using as examples some of the most common insulation materials used for buildings in the EU market, i.e. rigid polyisocyanurate foam, rigid phenolic foam, rigid expanded polystyrene foam and low density flexible stone wool. A characterisation of these materials, based on a series of ad-hoc Cone Calorimeter and thermo-gravimetric experiments, serves to establish the rationale behind the quantification of the critical temperature. The temperature of the main peak of pyrolysis, obtained from differential thermo-gravimetric analysis under a nitrogen atmosphere at low heating rates, is proposed as the “critical temperature” for materials that do not significantly shrink and melt, i.e. charring insulation materials. For materials with shrinking and melting behaviour it is suggested that the melting point could be used as “critical temperature”. Conservative values of “critical temperature” proposed are 300°C for polyisocyanurate, 425°C for phenolic foam and 240°C for expanded polystyrene. The concept of a “critical temperature” for the low density stone wool is examined in the same manner and found to be non-applicable due to the inability to promote a flammable mixture. Additionally, thermal inertia values required for the performance-based methodology are obtained for PIR and PF using a novel approach, providing thermal inertia values within the range 4.5 to 6.5 × 103 W2 s K−2 m−4.


Insulation materials Fire hazard Pyrolysis onset Performance-based design Critical temperature Fire performance Flammability 



Specific heat capacity (J kg−1 K−1)


Error function


Heat transfer coefficient (W m−2 K−1)


Conductivity (W m−1 K−1)


Thickness or length (m)

\( \dot{m} \)

Mass flow (kg s−1)

\( \overline{\text{Nu}}_{L} \)

Nusselt number (–)

\( {\text{Ra}}_{L} \)

Rayleigh number (–)


Time (s)

\( \dot{q}^{\prime\prime} \)

Heat flux (W m−2)


Temperature (K or °C)


Space (m)

Greek Letters


Absorptivity (–)


Density (kg m−3)


Thermal diffusivity (m2 s−1)


Stefan–Boltzmann constant (W m−2 K−4)





Of convection




External/incident radiation


Of ignition


Of pyrolysis


Of radiation


Of the surface


Total, considering convection and radiation

Of ambient



Critical heat flux


Carbon monoxide


Carbon dioxide


Differential thermo-gravimetric analysis


Expanded polystyrene


Locally weighted scatterplot smoothing




Rigid polyisocyanurate foam


Rigid phenolic foam


Stone mineral wool


Thermo-gravimetric analysis



The authors would like to gratefully acknowledge funding contribution from Rockwool International A/S towards the Ph.D. studies of Juan P. Hidalgo. Alastair Bartlett is gratefully acknowledged for his contribution with the Cone Calorimeter experiments. Michal Krajcovic is gratefully acknowledged for his precious lab assistance on the performed experimental programmes.


  1. 1.
    BS EN 13501-1 (2009) Fire classification of construction products and building elements. Part 1: Classification using data from reaction to fire testsGoogle Scholar
  2. 2.
    BS EN 1363-1 (2012) Fire resistance tests—part 1: general requirementsGoogle Scholar
  3. 3.
    BS EN ISO 1182 (2010) Reaction to fire tests for products—non-combustibility testGoogle Scholar
  4. 4.
    BS EN ISO 1716 (2010) Reaction to fire tests for products—determination of the gross heat of combustion (calorific value)Google Scholar
  5. 5.
    BS EN ISO 11925-2 (2010) Reaction to fire tests—ignitability of products subjected to direct impingement of flame. Part 2: single-flame source test.Google Scholar
  6. 6.
    BS EN ISO 13823 (2010) Reaction to fire tests for building products—building products excluding floorings exposed to the thermal attack by a single burning itemGoogle Scholar
  7. 7.
    ICC (2014) 2015 International Building Code—IBC. International Code Council, Inc., USAGoogle Scholar
  8. 8.
    NFPA (2015) NFPA 5000—building construction and safety code. NFPA, QuincyGoogle Scholar
  9. 9.
    ASTM E84 (2014) Standard test method for surface burning characteristics of building materials.Google Scholar
  10. 10.
    ASTM E119 (2012) Test methods for fire tests of building construction and materials. doi: 10.1520/e0119-12a
  11. 11.
    ISO 9705 (1993) Fire tests—full-scale room test for surface productsGoogle Scholar
  12. 12.
    Hidalgo JP, Welch S, Torero JL (2015) Performance criteria for the fire safe use of thermal insulation in buildings. Constr Build Mater 100:285–297. doi: 10.1016/j.conbuildmat.2015.10.014 CrossRefGoogle Scholar
  13. 13.
    Drysdale DD (1986) Fundamentals of the fire behaviour of cellular polymers. In: Buist JM, Grayson SJ, Woolley WD (eds) Fire and cell polymer. Springer Netherlands, Dordrecht, pp 61–75CrossRefGoogle Scholar
  14. 14.
    Hidalgo JP, Welch S, Torero JL (2015) Design tool for the definition of thermal barriers for combustible insulation materials. In: Proceedings of 2nd IAFSS European symposium of fire safety scienceGoogle Scholar
  15. 15.
    Lautenberger C, Fernandez-Pello C (2009) Generalized pyrolysis model for combustible solids. Fire Saf J 44:819–839. doi: 10.1016/j.firesaf.2009.03.011 CrossRefGoogle Scholar
  16. 16.
    Wasan SR, Rauwoens P, Vierendeels J, Merci B (2010) An enthalpy-based pyrolysis model for charring and non-charring materials in case of fire. Combust Flame 157:715–734. doi: 10.1016/j.combustflame.2009.12.007 CrossRefGoogle Scholar
  17. 17.
    Drysdale D (2011) An introduction to fire dynamics, 3rd edn. Wiley, New YorkCrossRefGoogle Scholar
  18. 18.
    BS 476-15, ISO 5660-1 (1993) Fire tests on building materials and structures. Method for measuring the rate of heat release of products.Google Scholar
  19. 19.
    Beyler CL, Hirschler MM (2002) Thermal decomposition of polymers. In: DiNenno PJ, Drysdale D, Beyler CL, et al (eds) SFPE handbook of fire protection engineering, 3rd edn. National Fire Protection Association, Quincy, pp 1110–1131Google Scholar
  20. 20.
    Quinn S (2001) Chemical blowing agents: providing production, economic and physical improvements to a wide range of polymers. Plast Addit Compd 3:16–21. doi: 10.1016/S1464-391X(01)80162-8 CrossRefGoogle Scholar
  21. 21.
    Dominguez-Rosado E, Liggat JJ, Snape CE, et al (2002) Thermal degradation of urethane modified polyisocyanurate foams based on aliphatic and aromatic polyester polyol. Polym Degrad Stab 78:1–5. doi: 10.1016/S0141-3910(02)00086-1 CrossRefGoogle Scholar
  22. 22.
    Babrauskas V, Twilley WH, Parker WJ (1993) The effects of specimen edge conditions on heat release rate. Fire Mater 17:51–63. doi: 10.1002/fam.810170202 CrossRefGoogle Scholar
  23. 23.
    ASTM E 2058 (2009) Standard test methods for measurement of synthetic polymer material flammability using a fire propagation apparatus (FPA). doi: 10.1520/E2058-09
  24. 24.
    Maani AQ (2013) Effects of oxygen concentration on the smouldering combustion of the rigid PIR insulation material. M.Sc. thesis, The University of EdinburghGoogle Scholar
  25. 25.
    Rasbash DJ (1976) Theory in the evaluation of fire properties of combustible materials. In: Proceedings of the 5th international fire protection seminar, Karlsruhe, Sept, pp 113–130.Google Scholar
  26. 26.
    Janssens M, Kimble J, Murphy D (2003) Computer tools to determine material properties for fire growth modeling from cone calorimeter data. In: 8th International conference on fire and materials, San Francisco, CA, pp 377–387Google Scholar
  27. 27.
    Long RT, Torero JL, Quintiere JG, Fernandez-Pello AC (1999) Scale and transport considerations on piloted ignition of PMMA. In: Sixth International Symposium of Fire Safety and Science, pp 567–578Google Scholar
  28. 28.
    Lloyd JR, Moran WR (1974) Natural convection adjacent to horizontal surface of various planforms. J Heat Transfer 96:443. doi: 10.1115/1.3450224 CrossRefGoogle Scholar
  29. 29.
    Mowrer F (2005) An analysis of effective thermal properties of thermally thick materials. Fire Saf J 40:395–410. doi: 10.1016/j.firesaf.2005.03.001 CrossRefGoogle Scholar
  30. 30.
    Hidalgo-Medina JP (2015) Performance-based methodology for the fire safe design of insulation materials in energy efficient buildings. Ph.D. thesis, The University of EdinburghGoogle Scholar
  31. 31.
    Gabbot P (2008) Principles and applications of thermal analysis. Blackwell Publishing Ltd, OxfordCrossRefGoogle Scholar
  32. 32.
    Sánchez-Jiménez PE, Pérez-Maqueda LA, Perejón A, Criado JM (2013) Clarifications regarding the use of model-fitting methods of kinetic analysis for determining the activation energy from a single non-isothermal curve. Chem Cent J 7:25. doi: 10.1186/1752-153X-7-25 CrossRefGoogle Scholar
  33. 33.
    Pérez-Maqueda LA, Criado JM, Sanchez-Jiménez PE (2006) Combined kinetic analysis of solid-state reactions: a powerful tool for the simultaneous determination of kinetic parameters and the kinetic model without previous assumptions on the reaction mechanism. J Phys Chem A 110:12456–62. doi: 10.1021/jp064792g CrossRefGoogle Scholar
  34. 34.
    Torero JL (2008) Flaming ignition of solid fuels. In: DiNenno PJ (ed) SFPE handbook of fire protection engineering. National Fire Protection Association, QuincyGoogle Scholar
  35. 35.
    Cleveland WS, Devlin SJ (1988) Locally weighted regression: an approach to regression analysis by local fitting. J Am Stat Assoc 83:596–610. doi: 10.1080/01621459.1988.10478639 CrossRefMATHGoogle Scholar
  36. 36.
    Wünsch JR (2000) Polystyrene—synthesis, production and applications. Rapra Publishing, ShropshireGoogle Scholar

Copyright information

© Springer Science+Business Media New York 2016

Authors and Affiliations

  • Juan P. Hidalgo
    • 1
    • 2
  • José L. Torero
    • 2
  • Stephen Welch
    • 1
  1. 1.School of EngineeringThe University of EdinburghEdinburghUK
  2. 2.School of Civil EngineeringThe University of QueenslandBrisbaneAustralia

Personalised recommendations