I.S.T. storage tanks can be equipped with impermeable and gastight conical roofs, flat steeldeck roofs, PVC roofs and GRP roofs. Each of these roof constructions have their own advantages and specific application field.
Conical and steeldeck roofs can be installed on the ground together with the top ring of sheets, the entire construction is then jacked up to construct the rest of the tank (click here for more info regarding the construction method of I.S.T. tanks). PVC and GRP roofs are lifted into place after tank construction. A PVC roof requires a middle column whereas GRP roofs are self supporting and can span large diameter tanks.