Abstract: The process includes the steps of removing a circle of ceiling sheet and cylinder of insulation material to create a work space under a portion of one of the I-beam-like roof bows and maneuvering in the space a U-shaped clamp having inward ribs at the upper end of its legs to straddle and hook over the bottom flange of the bow. A threaded rod extending through a threaded bore in the bight of the clamp is tightened to fix the clamp to the bow. A bearing nut with a wide plate is then screwed onto the lower end of the rod so that the plate engages and supports the sheet. Insulation is then injected into the space.