I am trying to build a heavy bag stand. I am going to place it outside in the car shed (which is open from three sides). I am wondering what is the best way to give it a strong base. The heavy bag will weigh around 200 pounds, and it will swing back and forth in all directions. This is where the problem comes in. I can't just put up an upside down capital L kind of structure. It will fall apart. I will be kicking the bag too. I can't permanently attach it to the ground.

I want to know what is the best way to build this frame so that it doesn't fall over or collapse on my head. And I need to do it within budget. The structure I designed below seems stable enough on paper, but it would be a bit expensive. I think I am missing perpendicular bars coming down straight from the top and splitting the triangles in half. That would make it stronger, but again very expensive. I have no experience with woodworking, but I am very thorough in my work and I pay attention to details.

What other structures would provide the same stability (or would be better) without costing me an arm? Can someone give me some advice?

And I was thinking of using either 2 inch x 4 inch x 8ft and may be a few 4 inch x 4 inch x 8ft

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  • Maybe try over at DIY or Sports SE. This is probably off-topic for WW. Off-hand, you don't have to worry so much about the static load downwards; the beam (if strong enough) will transfer to the triangle (if strong enough) just fine. It's the dynamic loads with radial velocity that will be the challenge. Think about how children's swing sets are built and installed. Most of the time they are staked into the ground.
    – user5572
    Commented May 27, 2020 at 15:04
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    I wonder if you're falling into the (fairly common) trap of redesigning the wheel here. I bet there's a homebuilt heavy bag support or two out there you could raid for ideas/inspiration, or just copy outright, where all the kinks have already been worked out.
    – Graphus
    Commented May 27, 2020 at 15:54

2 Answers 2


Basically, you're building a swing set for a single swing with a 200lb rider. The difference is that this swing can go a full 360° instead of just back-and-forth.

Treating this as a "shelf" and using the Sagulator, I picked Eastern White Pine as an example of the standard type of "SPF" (spruce, pine, fir) that you're likely going to pick up at the local big box store.

I spec'd a 4x6" top bar* (4" deep "shelf", 6" thick, i.e. placing the 4x6 with the 6" face vertical) with a 200 lb single point load and an 8' span. It says that there would only be 0.01" total sag over the span, which it deems "acceptable" for a shelf and seems quite reasonable.

Note: this is for a static load. You're gonna be kicking the tar out of this thing, so it's going to be swinging all over the place. That's going to put significant dynamic load on your "shelf" and will significantly increase the momentary sag and the long term stress on this top bar.

If you adjust your plan to use a 4x6" top bar, I think you'll have a reasonably secure mounting point for your heavy bag.

To support this mounting point (the 4x6"), your triangles are the most stable platform you can design. There is no need for an additional vertical splitting each triangle. You'll probably want to make the diagonals from 4x4 material to resist the dynamic forces you're going to impart. I'd suggest 2 @ 2x4 to connect the bottom of the 4x4s - one on each side to keep them from spreading.

HOWEVER, the one thing still not accounted for is racking forces. Your design will keep this from tipping in the direction of the triangles. There is nothing to prevent it from tipping along the axis of the top bar (one triangle toward the other).

To prevent this, you'll need some diagonal bracing from the top bar to the triangle braces. I'd suggest that on each end, you run one diagonal from the bottom of the 4x6 to the bottom of the triangle on each side. You'd want these diagonals to intersect the top bar at about 1/3 distance (about 25-30" in from each end) and run down to the center of the bottom cross member. Where they intersect the 2x4 at the bottom, I'd put a piece of 4x4 in between as blocking to strengthen and recruit both of the 2x4s to help resist racking.

An afterthought on the diagonal bracing: If you need all the space between the triangles and think that the internal bracing would get in your way, you could build a right-triangle on the outside of each triangle. This would attach at the end of the 8' 4x6 and extend the overall length of the apparatus. I'd use the same 45° angle to extend the triangle outwards, then use some more 2x4 to attach the bottom of this angled piece of 4x4 (one on each side, just like the main triangles) to the center of the 2x4 bracing at the bottom of the other triangles. Connect these using some 2x4 joist hangers.

  • Will all this extra and larger lumber blow your budget? Absolutely!
  • Will the one-time purchase price be lower than an ongoing gym membership? You bet!
  • Will the lumber costs be cheaper than a trip to the ER if this fails on you? Without a doubt.

Final tips:

  • This will experience tremendous loads as you swing that heavy bag around. Make sure your joints are cut accurately and tightly.

  • Don't skimp on fasteners.

    • There are lumber screws that are designed for construction loads. They're pretty pricey, but they're worth it for this kind of construction. They'll hold better than nails. Nails will pull out under these loads.
    • Don't try to use drywall screws (designed for interior drywall) or decking screws (designed to hold thin deck down vertically over joists).
  • You may want to add some metal mending plates to reinforce joints and some "joist hanger" or "rafter tie" type of plates to hold on the inside corners.

    • Some common sense while looking at the types available at your local big-box will help you understand what they have and where to apply them to your construction.
    • Pick up a box of "joist hanger nails" while you're there getting your metal reinforcements. They're specifically designed for the holes in the hangers and are short enough to not poke through the other side of the 2x material. You could go whole hog and splash out a few extra bucks for "joist hanger screws", just to be sure. With the fairly small quantity you'll use, it shouldn't be too much more.

* Just out of curiosity, I spec'd a 4x4" and even a 2x4" and it deems them all to be "acceptable" for static shelf loads. I would think neither of these would take the stresses of the very live load you're going to have. I wouldn't use either of these.

  • 1
    Bravo. Take note people, this is an Answer.
    – Graphus
    Commented May 27, 2020 at 15:31
  • 1
    Thank you kind sir! blushes
    – FreeMan
    Commented May 27, 2020 at 15:37
  • 1
    @FreeMan Wow this is amazing. I really appreciate the detailed feedback. Thanks very much, your answer gave me a lot of things to consider that I missed.
    – AIQ
    Commented May 27, 2020 at 16:28
  • Glad I could help, @AIQ. This may well have been a better fit over at Home Improvement, to be honest, but, as it's made of wood... :) Do take your time to ensure that you have good fits at all your joints, there will be a lot of stress on this construction.
    – FreeMan
    Commented May 27, 2020 at 16:32

The structure I designed below seems stable enough on paper...

I would disagree with your appraisal. For clarity I refer to the direction of the triangular base pieces as 'front/back' and the overhead beam as 'side to side'. While the triangles give the structure stability front to back, there is little to no bracing side to side. All the stress of the movement in any direction must be transferred to the ground and it is transferred through the connection of the triangular tops. No matter which way you impact the bag all of the force is transferred to the structure at top pivot point of the bag and this point must be stabilized in all directions.

  • To resist the front to back force direction you need to have a broader top beam. You could add another 2x8 top plate to the vertically oriented beam to create a 'T' shaped beam. The current beam is only 1 1/2" wide in the front to back direction and needs a wider profile to transfer the strike force.
  • To resist side to side force you must add diagonal braces top beam to each side of the triangular sides. The larger they are the better. I would attempt to start them several feet from the bag pivot point and extend them around halfway down the triangular side pieces.
  • If you get the clearances you require, you might consider tilting the side triangles toward the pivot point to shorten the length of the top beam.
  • Your connections are critical. Use screws or bolts, not nails to insure that the connections do not loosen over time. The junction of the wood members should be flush, which means you will need to cut odd, but exact angles. Of course the more permanent the connections, the more difficult it will be to make it portable (if that is a criteria for you).
  • Your 2x4 size seems adequate, but the top beam should be 2x8.

You mentioned that this is in a carport. If you could cross brace the carport structure it might be possible to simply hang it under the roof.

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