Abstract: A support for holding a fluid-impervious barrier and/or keyway form in position during the pouring of concrete is provided. The support carries the barrier and a pair of spaced legs for attachment to a corresponding pair of stable mounting points, such as reinforcement members, bars or the like. The support is positioned such that the barrier is at least partially covered by concrete during the pouring of a first member, such as a slab or footing, and then the remainder is covered when a second concrete member, such as a wall, is poured atop the first member. By placing a plurality of spaced supports at selected intervals, an elongated barrier may be reliably held in place during pouring. One or more forms may also be carried by the support during the pouring of the first concrete member for defining a keyway, either alone or in conjunction with the fluid-impervious barrier. Most preferably, each keyway form is held in place by a separate wing carried on each support.