Fire ventilation

chapter 6Creating openingsOpenings are an essential part of the work with fire ventilation.We will consider here the methods where openings aremade manually by means of hand tools. Explosive cuttingframes and water cutting are methods that require specialtraining and special equipment, and will only be consideredin general terms.There are no general methods that can be applied forcreating openings in roofs during fire ventilation in a fireand rescue operation (with the exception of explosive cuttingframes and water cutting, which can be used in severaldifferent situations). On the other hand there are a largenumber of suitable tools that can be used, and certain guidelinescan be given for creating openings in several commontypes of roof structures.There are several factors that influence how successfulventilation can be implemented by creating openings in aroof. Examples of such factors are:• the fire scenario and intensity of the fire• room volumes and geometries• the size and positioning of inlets• the prevailing wind conditions• access to mechanical ventilation• the capacity of the fire fighting crew• equipment to create openings• the roof structureThe roof structure influences the tactics during the fire andrescue operation. It also influences the positioning and sizeof the openings, the time for and problems with the workof making the openings, including the safety precautions75