The heavy bag is an iconic and indispensable tool for training in boxing and other martial arts, says Oregon-based martial arts teacher Dave Coffman. Most martial arts schools have one on hand, but over the course of your training, you may want to install one at home. If your home has visible, easy-to-access ceiling joists, installing a bag is fairly easy. If not, you'll need to build a wall-mounted frame to withstand the weight and jostling of a frequently used heavy bag.
Measure the ceiling height in the room where you want to mount your bag. Measure the distance between the two walls closest together in the same room.
Cut both 84-inch beams to a length 6 inches shorter than the height of your room. These will be the support legs of your frame. For example, if the ceiling height is 88 inches, you would cut each beam to 82 inches. If the ceiling height is 90 inches or greater, don't cut these beams.
Cut the 120-inch beam to a length 11 inches shorter than the distance between the walls in your room. This will be the top joist of your frame. If the room is wider than 131 inches, you can either find a narrower place to mount your bag or find a longer beam.
Drill a 1/4-inch-diameter hole through the exact center of your top joist, halfway between both ends and halfway between both sides. You may need to start by drilling a smaller hole, then widening it with progressively wider bits.
Drill four 1/4-inch-diameter holes, 2 inches deep, in each end of your top joists. Space these in a square 2 inches on a side, centered on the end of the joist.
Install a lag nut in each of the holes you drilled in the ends of the top joist.
Drill four sets of four 1/4-inch-diameter holes through both of your support beams. Each set should be a square, 2 inches on a side, with two sides each 1 3/4 inches from the long sides of the beam. Place the first set 1 3/4 inches from one end of each beam. Place the second set 24 inches from the first set. Place the third set 36 inches from the second set.
Sand all faces of the lumber.
Slide your eyebolt through the hole you drilled on center in the top joist. Tighten down the nut to hold it in place.
Hold up your support beams against the wall where you will place them. Confirm that they are set along wall studs. Mark the wall through the holes you've drilled. Set the beams aside.
Drill two sets of four holes in each wall, where you marked it through the holes in your beams.
Install lag nuts in each of the holes you drilled in the walls.
Set one support beam in an L shape with the top joist, holes aligned. Connect them by screwing the lag bolts through the holes in the beam and into the nuts in the top joist. Confirm that the eye of the eyebolt is pointing in the same direction as the open end of the support beam.
Repeat step 5, forming a C shape by attaching the other support beam to the free end of the top joist.
Turn the C-shaped frame upright, with the top joist toward the ceiling. Slide it into place with the beams aligned with the holes you drilled in your wall. This step is much easier if done with a helper.
Attach the frame to your walls by driving lag bolts through each hole and into the nuts you installed in your walls.
Place the ladder directly beneath the eyebolt in the frame.
Set the heavy bag on the bottom rung of the ladder. Walk the heavy bag up the ladder one rung at a time until the top is less than two feet from the eyebolt.
Slip the top of the mounting chain through the eye of your eyebolt. Hook the chains to the heavy bag.
Reinforce the chains connected to the bag with one carabiner at each hook.