Abstract: A partition, mounted on a mounting surface, comprises a plurality of elongate upright members, a first board and a second board. The first board is mounted on one side of a pair of the elongate upright members that are adjacent to each other, and the second board is mounted on the other side of the same pair of adjacent elongate upright members, so as to provide a cavity between the pair of elongate upright members and the first and second boards. The partition further comprises a spacer that is located within the cavity, the maximum dimension of the spacer in the through-thickness direction of the partition being at least 90% of the separation of the two boards. The spacer may help to reduce the extent of inward bowing of the boards between adjacent elongate upright members, so that, for example, the upright members may be spaced further apart.