13. Bulkhead frame installation instructions. 1 Assembly of the bulkhead frames. Assemble the bulkhead frames , these are essentially upside down kick boxes. 2 Installing the bulk head frames. Position the frames so that it sits on top of the carcases 20mm back from the front edge. 3 Installing a bulk head over a range hood canopy. Fix plaster to the underside of the frame then install the frame into position. Tip, Prior to installing the frame make sure you have allowed for the flue to be installed. Note; With this option you need to allow for the total depth of the flue + the splash back. 4 Installing the plaster board. Cut the plaster board neatly with a sharp knife and fix to the bulkhead framing. Ask at your plaster board supplier about cutting plasterboard. Tip, Make sure that the edge of the plaster board that is to rest on top of the cabinets is trimmed neatly so it fits snuggly on top.