Field fabrication of roof insulation drain sumps is a major labor time sink and waste of material. CertainTeed's Target Sumps are ready to use, perfectly tapered drain accessories. 8' x 8' Hinged Target Sumps are pre-assembled with FlintBoard® ISO or FlintBoard® ISO Cold, 25 PSI with perimeter edge thicknesses of 1.5”, 2”, 2.5” or 3”. Just unfold, center on the drain, and cut out the hole size required. 4' x 4' Target Sumps are manufactured with FlintBoard® ISO Cold, 25 PSI only. This sump comes pre-assembled with ½” slope in thicknesses of 0.5" to 2.0".