A numerical comparison of protective measures against external fire spread

Research output: Contribution to journalArticle


The impact of different passive protective measures against external vertical fire spread was investigated using the numerical tool Fire Dynamics Simulator (FDS). The numerical study was divided into a validation study and a comparative analysis. The validation study was performed to evaluate FDS as a calculation tool for modelling external vertical fire spread and was conducted using experimental results from a large-scale fire test done on a SP FIRE 105 test rig at SP, Sweden. It was concluded that FDS 6.2.0 could reproduce the experimental results with a reasonable level of detail. In the comparative analysis, the impact on the external fire from a smaller apartment was studied in FDS with different configurations of horizontal projections and spandrels in the building exterior. Also, the effects of an upper and lower facade set-back configuration were studied. The results show that facade solutions based on a horizontal projection or an upper facade set-back configuration result in comparable or better protection compared with a defined spandrel height. The results also show that a spandrel height of at least 1.2 m can be replaced by a 60-cm-deep horizontal projection, given that the balcony is wider than the underlying opening.


  • Markus Nilsson
  • Bjarne Husted
  • Axel Mossberg
  • Johan Anderson
  • Robert Jansson Mcnamee
External organisations
  • SP Technical Research Institute of Sweden
  • Brandskyddslaget AB
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Other Civil Engineering


  • External fire spread, Facade set-back, FDS, Fire safety engineering, Horizontal projection, Spandrel
Original languageEnglish
Pages (from-to)493-507
JournalFire and Materials
Issue number5
Early online date2018 Jan 1
Publication statusPublished - 2018 Aug
Publication categoryResearch