Step 1
Look at the ceiling where you want to mount the punching bag and draw up a list of mounting options for the designs and materials you are working with. If you have exposed wood joists in the ceiling, you can drill a hole in one joist or use a rafter hanger attached to two joists. For a plywood ceiling, you can attach an eye-loop hanger with wood screws, but for a drywall ceiling you must use drywall anchors and screws or molly bolts instead. Alternately, you could drill through a drywall ceiling and mount an eye-loop screw into a wood joist behind it.
Step 2
Calculate how much weight each of your mounting options can support, adjusting for the ceiling material. If you have an eye-loop hanger with four screw holes held into a drywall ceiling by 30-lb. drywall anchors, then the hanger should support 120 lbs., but drywall is a brittle material. That might be enough for a very small heavy bag or a double-end bag, but not for a midsize or large heavy bag. The same mount in plywood, on the other hand, could handle more weight and shock.
Step 3
Increase the listed weight of the punching bag to provide a margin for the wear and tear value of shock on the ceiling mount, since punching bags shake with every blow. For a heavy bag, increase the weight by between 1/3 and 1/2. For a double-end bag, which weighs very little but gyrates wildly, double or triple the weight.
Step 4
Compare your calculations of how much weight and shock the heavy bag will place on the ceiling mount against your list of ceiling mounting options. This will tell you if your ceiling can support the heavy bag you want to hang from it.