Fire ventilation

12 3The circular saw is used to saw wood and plasterboard. Itis effective and relatively easy to carry during an operation.It can be used for both boarding and supporting parts inwooden roof structures. The sawing depth varies from 50–70 mm, depending on the manufacture.The electric chainsaw is handy for creating openings inwooden structures. Its function can be impaired by nailsand metal jointing in the roof structure. When creatingopenings in wooden roofs covered with tarred roofing felt,the blade can stick because of the tar.A special machine is used as a screwdriver, or a batteryoperated drilling machine is fitted with screwdriver bits ornut sleeve. The screwdriver is useful when it is necessary toremove sheet metal roofing that has been screwed on.The chainsaw is handy for creating openings in woodenstructures. Its function can be impaired by nails and metaljointing in the roof structure. When creating openings inwooden roofs covered with tarred roof roofing felt, the bladecan stick because of the tar.1. Chainsaw2. Power cutter.3. Power cutter withalternative blade.79