Abstract: A tank for storing liquids, particularly of the vaporized type. A floating roof on the tank includes a peripheral seal which slideably engages the tank inner wall to maintain a degree of sealing as the roof adjusts in response to variations in the liquid level. A plurality of sleeves to depend downwardly from the roof underside to support the latter when the tank has been emptied and is no longer supported on contained liquid. A column is slidably received in each sleeve and is adjustable to limit downward movement of the roof when in the non-supported mode to facilitate the cleaning of the tank interior.