Firestopping Book Firestopping Book | Page 160

ENGINEERING JUDGEMENT As explained in the previous chapters, very often the Jobsite curtain wall conditions differ from the original design or unanticipated construction hindrances are encountered and the field conditions cannot be easily redesigned. As there are multiple components involved in the curtain wall design, hence there could be multiple factors in the curtain wall design installed at site which can vary from the system which is tested with laboratories like Intertek & UL. Generally, these variations in changes at site or design from the unit which is actually tested, cannot be easily or cost effectively redesigned so alternative methods must be implemented to maintain the integrity of the system. And this is why it is important that these principles be developed via sound engineering principles and good judgement. IFC Engg Guidelines Perimeter Fire Barrier system engineering judgments should: ■ ■ ■ ■ ■ ■ Not be used in lieu of tested systems when tested systems are available. Be issued only by firestop manufacturer’s qualified technical personnel or, in concert with the manufacturer, by a knowledgeable registered Professional Engineer, or Fire Protection Engineer, or an independent testing agency that provides listing services for the systems. Be based upon interpolation of previously tested perimeter fire barrier systems that are either sufficiently similar in nature or clearly bracket the conditions upon which the judgment is to be given. Additional knowledge and technical interpretations based upon accepted engineering principals, fire science and fire testing guidelines (e.g. ASTM E 2032 – Standard Guide for Extension of Data from Fire Endurance Tests) may also be used as further support data.