Galvanized Flat Roof Flashing Hercules manufactured flat roof jacks are 12" in height. The 1/2" sizes are designed to fit double-wall flue pipe. SKU .5FRF Product Details | Specifications | Check Inventory Please select 1/2" FLAT ROOF FLASHING 2" FLAT ROOF FLASHING 3" FLAT ROOF FLASHING3 1/2" FLAT ROOF FLASHING 4" FLAT ROOF FLASHING4 1/2" FLAT ROOF FLASHING 5" FLAT ROOF FLASHING 5 1/2" FLAT ROOF FLASHING 6" FLAT ROOF FLASHING 6 1/2" FLAT ROOF FLASHING7 3/4" FLAT ROOF FLASHING 8 3/4" FLAT ROOF FLASHING 10" FLAT ROOF FLASHING11" FLAT ROOF FLASHING 12" FLAT ROOF FLASHING 13" FLAT ROOF FLASHING 14" FLAT ROOF FLASHING 15" FLAT ROOF FLASHING 16" FLAT ROOF FLASHING 17" FLAT ROOF FLASHING Log in to view price