Formwork element for concrete construction, comprising a lower formwork part, an upper formwork part, a slotted formwork part, a horizontal sheet metal material strip designed as a flat water barrier, and a vertical sheet metal material strip designed as a flat water barrier, wherein the lower formwork part, the upper formwork part and the slotted formwork part are arranged in a common plane, wherein the horizontal sheet metal material strip is arranged between the formwork parts (1, 2, 3) in such a way as to be aligned essentially perpendicular to the plane of the formwork parts (1, 2, 3), wherein a first surface of the horizontal sheet metal material strip faces the upper formwork part and the slotted formwork part, and a second surface of the horizontal sheet metal material strip faces the lower formwork part, and the horizontal sheet metal material strip protrudes over the plane of the formwork parts (1, 2, 3) on both sides, wherein the upper formwork part and the slotted formwork part are firmly connected with the first surface of the horizontal sheet metal material strip, and the lower formwork part is firmly connected with the second surface of the horizontal sheet metal material strip, wherein the vertical sheet metal material strip is arranged between the upper formwork part and the slotted framework part in such a way as to be essentially perpendicularly aligned to the plane of the formwork parts (1, 2, 3), wherein a first surface of the vertical sheet metal material strip faces the upper formwork part and a second surface of the vertical sheet metal material strip faces the slotted formwork part, and the vertical sheet metal material strip protrudes over the plane of the formwork parts (1, 2, 3) on both sides, wherein the upper formwork part is firmly connected with the first surface of the vertical sheet metal material strip, and the slotted formwork part is rigidly connected with the second surface of the vertical sheet metal material strip by way of a partial area of its expansion that extends in a vertical direction proceeding from the first surface of the horizontal sheet metal material strip, wherein the horizontal sheet metal material strip and the vertical sheet metal material strip are arranged perpendicular to each other, and are firmly connected with each other, wherein a slot-like recess is provided between the second surface of the vertical sheet metal material strip and the slotted formwork part, wherein the slot-like recess proceeds from the edge of the slotted formwork part facing away from the first surface of the horizontal sheet material strip to extend over at least 3% of the vertical expansion of the slotted formwork part. wherein the lower formwork part, the upper formwork part and the slotted formwork part are arranged in a common plane, wherein the horizontal sheet metal material strip is arranged between the formwork parts (1, 2, 3) in such a way as to be aligned essentially perpendicular to the plane of the formwork parts (1, 2, 3), wherein a first surface of the horizontal sheet metal material strip faces the upper formwork part and the slotted formwork part, and a second surface of the horizontal sheet metal material strip faces the lower formwork part, and the horizontal sheet metal material strip protrudes over the plane of the formwork parts (1, 2, 3) on both sides, wherein the upper formwork part and the slotted formwork part are firmly connected with the first surface of the horizontal sheet metal material strip, and the lower formwork part is firmly connected with the second surface of the horizontal sheet metal material strip, wherein the vertical sheet metal material strip is arranged between the upper formwork part and the slotted framework part in such a way as to be essentially perpendicularly aligned to the plane of the formwork parts (1, 2, 3), wherein a first surface of the vertical sheet metal material strip faces the upper formwork part and a second surface of the vertical sheet metal material strip faces the slotted formwork part, and the vertical sheet metal material strip protrudes over the plane of the formwork parts (1, 2, 3) on both sides, wherein the upper formwork part is firmly connected with the first surface of the vertical sheet metal material strip, and the slotted formwork part is rigidly connected with the second surface of the vertical sheet metal material strip by way of a partial area of its expansion that extends in a vertical direction proceeding from the first surface of the horizontal sheet metal material strip, wherein the horizontal sheet metal material strip and the vertical sheet metal material strip are arranged perpendicular to each other, and are firmly connected with each other, wherein a slot-like recess is provided between the second surface of the vertical sheet metal material strip and the slotted formwork part, wherein the slot-like recess proceeds from the edge of the slotted formwork part facing away from the first surface of the horizontal sheet material strip to extend over at least 3% of the vertical expansion of the slotted formwork part.