|۱||fixed cross jack|
Roof jacks may be used for ordinary formwork in performing concrete slab and spar block ceilings. These jacks have 1500 Kg load capacity and produced for 3.5 m height which may be changed to 4, 4.5 and 5 m heights based on request of customer. Formwork will be easier under concrete beams by connection of T jacks on roof jacks. These T and U jacks produce 20 to 25 cm increase in height. Jacks of Parsian Ghaleb Industrial Group are manufactured by heavy pipes and bolt with 7 steps and nut from ductile shatterproof cast iron and bolt and nut with 6 steps and nut from steel. At more than 5 m heights, use of modular scaffold is proposed instead of roof jacks. Internal pipe and external pipe of roof jacks have 5 cm and 6 cm diagonal and sheet thickness of pipes is 2.5 mm.