Height extrapolation of fire resistant non-loadbearing steel framed walls

A review of height extrapolation methods used in the past, by BRANZ, has shown that complex techniques based on temperature rises inducing deflections, curvature and detachment of studs from channels can be reduced to a simple empirical formula. Given that a wall system comprising a certain stud and lining configuration has to be proven by a fire resistance test, a premise that the same or closely similar thermal and structural conditions will be reproduced within the wall is the basis of the proposed method. Four key features (of height, stud depth, lining and temperature difference across the studs) affecting the general performance of a wall were examined to determine some key dependencies and isolate irrelevant parameters from further consideration. This approach was possible by taking a macroscopic view of a system as a whole, and by assuming for all height and stud depth combinations of a given system that the behaviour is similar and predictable to a high degree. Copyright © 2002 John Wiley & Sons, Ltd.