The base of the dike should be about three times as wide as the dike is high to provide adequate friction area between the ground and sandbags. Place the same number of rows on the bottom layer as there will be vertical courses of bags to obtain the triangular shape. The second layer of bags should be perpendicular to the first layer, then alternate the direction of the bags to the top of the dike, alternating header courses (bags placed crosswise) and stretcher courses (bags placed lengthwise).
Place the first layer of bags lengthwise of the dike (parallel to the flow), overlapping the bags so the filled portion of one bag lies on the unfilled portion of the next, with the untied open end of the bag facing downstream. Offset adjacent rows or layers by one-half bag length to eliminate continuous joints, similar to what is done laying bricks. Compact and shape each bag by walking on it. Continue to walk on the bags as succeeding layers are placed to eliminate voids and form a tight seal.
