Abstract: A bag closure is provided for containing flowable material such as powdered cement and mortar. The closure includes loosely folded, overlapping end flaps which are secured together by an overlying peel-away sheet. Where the bag is to be filled with moisture sensitive materials, the peel-away sheet is preferably impermeable to water vapor and forms a vapor barrier closure. The peel-away sheet, which preferably controls the moisture content within the bag during storage, includes a graspable tab that is used to peel the sheet at least partially away from the loosely folded flaps of the bag. An end tuck of the bag may then be unfolded to provide a pour spout for the contents of the bag. The closure eliminates the need for prior art pull strings or sewn ends which are not easy to open and which do not adequately resist moisture penetration.