Fire Safety Engineering
David Barber, Principal, Australasia Fire Leader, ARUP
Internationally and locally, timber and wood products are increasingly specified for major construction projects as a fire safe building material. Integrating design principles and fire engineering can ensure the required performance and compliance with relevant building codes.
7. Concept 1:Can Fire Performance Be Predicted ? Fire performance of wood has been studied for many years: Research dates back to 13th century Solid wood has highly predictable performance in fire Little variability between countries in species type Knowledge = data = confidence
14. Concept 3:How Does Wood Burn ? Char: Natural protection for wood Allows for continued, but diminishing strength during a fire Well studied and well understood and is predictable Different wood – different char (due to density and water content)
17. Concept 4:Expected Fire Performance National Construction Code: Performance Requirement CP 1 - “A building must have elements which will, to the degree necessary, maintain structural stability during a fire appropriate to.......” Structural wood needs to provide an equivalent level of performance as concrete or steel
27. Concepts:Summary Concepts for fire performance of wood: Fire performance is well understood Not all wood is the same - scale matters Solid wood chars – which has predictable performance in fire In a fully developed fire, wood can perform equivalent or better than steel
30. Class 2 or 3 (residential) – Rise in storeys of 3 or moreType A - all elements must be non-combustible (except a mezzanine), hence no wood permitted.......
31. What Does the NCC Allow for Solutions in Wood ? So, how is wood used in buildings ? NCC allows fire engineering solutions for areas of non-compliance (so called “performance based” approach) Fire engineering solutions will need a good fire engineer, who understands structural wood solutions, understands the process of approval and design implementation
40. Case Study – 5 Storey Building Solid wood structure of columns and beams, inherent FRL with load bearing capacity in excess of 60 mins FRL Wood assumed to not have any plasterboard protection (not required to be maintained) Steel would require protective coating (sprayed or paint) to achieve 60 mins FRL (requiring maintenance)
43. Edge detailsPenetrations for building services are complex to solve Facade interface with wood edge beams are problematic
44. Case Study – 5 Storey Building Case study summary: Performance requirements of the NCC can be met using structural wood Designs can gain approval, provided the engineering is substantive Similar approach to any other fire engineered solution
45. Summary Wood does burn – but we understand how Structural wood is equivalent or better than structural steel in many built situations A lack of understanding of the fire performance of wood by many Wood can be used, but you need a fire engineering solution
46. Does Wood Burn ? The Fire Safety of Solutions in Wood Questions? David Barber Arup Fire Group Leader – Australasia Region