Dimensions and Complexity
The first thing you need to decide is how many different types of exercises you want to do with your home bench press. The standard bench press found in most gyms consists of a flat surface (the bench) attached to a series of upright racks that hold the weight. If you want to build one that resembles one of these, you can download the measurements from an online catalogue.
The simplest setup consists of a picnic table bench (or a 2-foot by 10-foot plank of wood laid across two milk crates or cinder blocks) with a pair of homemade racks to support the weight. You can construct the latter from two-inch-diameter pipes, with a J hook welded into the top end and the bottom end cemented into a small tire.
However, the more exercises you want to do with your home bench, the more complex you have to make it (and the greater difficulty that goes into building one). For example, to build a home bench press that allows you to perform military presses, you will have to make the upright racks adjustable for different heights. To use your home bench press to do incline or decline presses, you will have to make the upright racks height-adjustable and you will also have to build a bench that can be adjusted to different angles.
Also, many powerlifters (especially those who specialize in competing in the bench press) like to do partial-lifts to improve their performance. A home bench that allows you to do these lifts would also require a set of adjustable supporting racks that flank the sides of the bench, so that you could perform a bench press from a number of different heights.
No matter what you build, make sure that it fits inside the area where you will work out. Also, if you plan on using a standard-size barbell (seven feet in length), make sure that your bench press can accommodate the barbell’s dimensions.
Also, if you are unusually tall or heavy, you will probably want to make sure that the bench press you build can accommodate your body size. It’s important to build a bench press that allows you to lift without feeling cramped. Also, your choice of material (wood metal, or plastic) will affect the amount of space on which you can place your body and the barbell. Using very thick metal pipes (or wood blocks) will diminish the interior space (for your body) where you join the upright racks and bench press together.
Choosing Your Material
If you want to build a more complex bench, you will need to first decide whether to build your bench primarily out of wood or metal. A bench press made out of wood needs to be sturdy enough to hold your body weight and the weight that you plan on lifting. Therefore, make sure to use pressure-treated material with thick enough dimensions (4x4s) that will not crack or break during exercise. Also, if building with wood, consider using metal parts for all the joints as these will be more durable.
If you choose to build out of metal, you can purchase the same material used in commercial scaffolding. These pipes hold 2,000 lbs. (though 2 ½-inch in diameter, 11-gauge steel should suffice). When building out of metal, use bolts to secure all parts together. This will provide you with a more durable power rack than if you had welded all the joints together.
Also, to provide greater comfort and to avoid chafing while lifting, many fitness enthusiasts will want to line the bench part of their homemade bench press with some sort of padded material, usually a compressed foam rubber.
As some lifters use more than 500 lbs. when performing their lifts, you should ultimately shoot to build a rack that is safe and will not collapse
How to Build a Bench Press
See the References section below for links to detailed step-by-step instructions, including schematics, for building your own home bench press.