Abstract: A system of placing and supporting elongated control joint strips, headers and the like preparatory to the pouring of a concrete slab, using elongated strips having V-shaped longitudinal bends, and spaced socket members defining non-circular sockets, in combination with stakes on non-circular cross section having two different effective transverse dimensions. The preferred stakes are of oval or elliptical cross section, with longitudinally spaced ring-like ribs on the shorter sides, and the preferred socket members are either integral U-shaped straps lanced from the strips, or separately formed brackets fitted onto the strips and having means defining non-circular sockets alongside the strips.