Wood I-Beam Floor Joists - hanging a heavy bag ???

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Forum topic by NBeener posted 09-29-2010 01:06 AM 41627 views 0 times favorited 18 replies Add to Favorites Watch
View NBeener's profile


4816 posts in 3198 days

09-29-2010 01:06 AM

Okay, so it’s a REAL stretch to consider this a WW question at all BUT … it KINDA is (!) and … lots of you are vast treasure troves of knowledge, so … here goes.

I bought a 70 pound heavy bag:

I want to hang it in my basement, ideally from the main level floor joists … which are … wood I-beams:

These I-beams are the real question mark, for me. If it were standard dimensional lumber, I wouldn’t have quite the same concerns, but …..

What’s the best way to do this ?

Here’s the “standard” heavy bag hanger:

Here’s the heavy bag joist hanger:

Or … I could use 2×6’s (or whatever), and build a platform across two of the joists, using long, beefy lag screws, and then hang the “standard” hanger from there.

Or ….. ??

Any thoughts ?

Clearly, I don’t want to mess ANYTHING up by doing this … and there WILL be some force on the mounting points, once (no bragging, here !) a person starts wailing away at the bag.

Thanks in advance !

OKAY. QUICK EDIT: There IS a big honkin’ steel I-Beam, supporting the whole thing. I could use that to hang the heavy bag from, using a thing like this:

Is THAT the “no-brainer” way to do it ? It wouldn’t put the bag just where I’d like it, but … it would be a location I could live with.

-- -- Neil

18 replies so far

View Bothus's profile


441 posts in 3200 days

#1 posted 09-29-2010 01:21 AM

I don’t think it will ever work. Neil. You should send the bag to me.


-- Jerry Boshear, Professional Kitchen Designer, amature woodworker.

View JasonWagner's profile


527 posts in 3203 days

#2 posted 09-29-2010 01:21 AM

I’m sure people will have lots of elegant ways to do this, but…

I’ve mounted a pull up bar from my engineered I beams and it holds me (175lb doing pull ups). I used some corse threaded lags up through the 2×3s with pipe brackets. That would be pretty comparable to your standard mount. Or screw up in like you said with a 2×6…that’s not a bad idea come to think of it.

The joist hanger looks like it’d work if you just maybe put some 3/4 material in the I beam to beef it up. Don’t know if the dimensions of the joist hanger would work that way however.

Those I beams won’t suffer from some holes through them. They’re made with punch-out holes to run pipes and wires through them.

-- some day I hope to have enough clamps to need a clamp cart!

View patron's profile


13606 posts in 3365 days

#3 posted 09-29-2010 01:21 AM

you can fill the ‘web’
on both sides
(glue and screw)
and use that hanger gizmo
(the heavy one)
through bolt it
hang from that

-- david - only thru kindness can this world be whole . If we don't succeed we run the risk of failure. Dan Quayle

View Tracey615's profile


19 posts in 2822 days

#4 posted 09-29-2010 01:27 AM

Ok, here’s the word from a retired Architectural Engineering instructor. First, the photo showing the hanger with the bag attached gives the answer. Attaching the metal hanger to TWO joists divides the load, half to each. Secondly, a load of 70# is not too much for only one joist. Most loads for floor joists are calculated for about 50#/sqft. If the bag is hung at the midpoint of the joist span, it will be at the maximum point of deflection. This is only bad if the joist is a 2X6 at least 12’ long. The joist shown with a plywood web will support upwards of 75#/sqft. The top flange will be in compression and the bottom will be in tension, in the application given, both will be stressed from the imposed load of the floor above. I think you are safe, but I would use 3/8” bolts through the web of the joist to secure the bag hanger.

Ok, just read the additional comment about the I beam. That is the way to go if you have the room. The weight of the bag is an afterthought to the beam.

-- Trace the Bald

View NBeener's profile


4816 posts in 3198 days

#5 posted 09-29-2010 01:54 AM

Jerry: I’ve seen video of you. I wouldn’t’ do that to my new bag. One punch from you … and … POOF ! Like a distant memory. Plus, shipping costs are brutal ;-)

The whole “onto the steel vs. into the engineered wood” is kind of dependent on what/if my wife ever finalizes what build-out SHE wants in the basement, so … really … having the answers about BOTH is great, since … it could start on steel, and then be moved to wood … whenever.

Sounds like some solid agreement (great SU drawing, by the way, shopguryl !): a bit of “sistering” (if I’m using the right word) should yield PLENTY of structural support.

And … specifically to Tracey615: THAT’s exactly why I figured it was worth posting, here. We’ve got at least one of EVERYTHING in this flock of ours. All that and cool buzz words, too !!! Thanks so much !

Yeah: I figured that … in terms of the wood … fat fasteners, plenty of them, and a decent amount of length was a given.

And … Jason ... pull-ups, and … don’t you lift beer kegs … up and down stairs, or something like that ? Note to self: don’t screw with Jason….. ;-)

-- -- Neil

View rimfire7891's profile


123 posts in 2926 days

#6 posted 09-29-2010 02:08 AM

Hi NB,

Screw a 4×8 sheet of 3/4 plywood to the bottom of you floor joists and mount your pivot to the ply. You could beef up the mount pad inside the floor joist space above where you want to mount the bag. Could also mount a large washer and nut on the top of the ply before you install it so you can bolt your bracket on. I would weld a 1/2” UNC nut to large square washer, drilled with four screw mounting holes to screw it to the ply top. This would spread the load over a few joists. Mount the ply with long side 90 degrees to the joist direction.

Good luck
Thanks jb

-- Playing with wood and metal for the last 50 years, driving and building Land Cruisers for the last 40. Experience is what you get when you don't know what you are doing.

View Beginningwoodworker's profile


13345 posts in 3697 days

#7 posted 09-29-2010 02:25 AM

I would screw it to the floor joists.

View Tony Strupulis's profile

Tony Strupulis

260 posts in 3147 days

#8 posted 09-29-2010 02:27 AM

I would recommend using the heavy bag joist hanger system. To make it work with the engineered joists, I would stiffen the web of both joists with a piece of 1/2” plywood attached to both sides of the web using TICO nails. This should bring you flush with the flanges and provide good shear transfer to the flanges.

I would caution strongly against using lag bolts on the flanges of the engineered joists. Those flanges are meant to be continuous and a lag bolt is a huge structural discontinuity.

-- Tony -

View swirt's profile


2777 posts in 2995 days

#9 posted 09-29-2010 04:00 AM

I second Tony’s caution about not mounting or drilling into the flange at top or bottom. Even a small hole in those changes decreases the strength of it by quite a bit.

-- Galootish log blog,

View MOJOE's profile


548 posts in 3292 days

#10 posted 09-29-2010 04:21 AM

I agree with Patron…...fill in the webs, this will give you more lumber to attach your bracket, and save you from trying to drive a bolt into the OSB.

-- Measuring twice and cutting once only works if you read the tape correctly!

View Dark_Lightning's profile


3165 posts in 3132 days

#11 posted 09-29-2010 04:25 AM

Hmm. My 2 cents. What is directly above the attach point? There could be a noise translation issue. If you wife is watching boxing while you’re down there injuring the bag, it’s probably a moot point. Baby’s crib, or the dog’s bed? Prolly not a good idea. Personally, I’d laminate some plywood to both sides of the OSB portion for anything like this. OSB in it’s state as you see it possesses great aggregate strength, but with all that pounding, I’d want local reinforcement to minimize the pounding from point loading, potentially tearing it locally. Also, I’d drill the holes mid beam, not near the top or bottom. A bag that big may do a good job of attenuating your wife-beatin’ urges, :) but I’m a conservative kind of guy when it comes to designing a structure.

-- Random Orbital Nailer

View Jim Bertelson's profile

Jim Bertelson

4179 posts in 3188 days

#12 posted 09-30-2010 12:47 AM

The only close to that that I own, I will have to send a picture of when I get home. I have a wooden closet rod just long enough for me to hang from with my hands, and it has been there at least 15 years, in use every week, with me hanging from it, over 200 pounds. It is in the garage, installed on the side of a beam.

I think everyone here has given you enough advice, I’ll send you the picture when I get home for your amusement.


-- Jim, Anchorage Alaska

View Dick, & Barb Cain's profile

Dick, & Barb Cain

8693 posts in 4323 days

#13 posted 10-06-2010 09:18 PM

I’d use the steel I-Beam if it’s available in the right place for you.

-- -** You are never to old to set another goal or to dream a new dream ****************** Dick, & Barb Cain, Hibbing, MN.

View NBeener's profile


4816 posts in 3198 days

#14 posted 10-06-2010 10:15 PM

Agreed, Dick.

The steel I-Beam just makes the most sense … at least for now.

I’ve ordered the hardware to attach it TO the steel.

Once it shows up … if I were that heavy bag … I’d find some place safe to hide <grin>

Thanks for the very helpful feedback, all. If/when it’s time to relocate it to the wood joists, I’ve got lots of great advice !

-- -- Neil

View Dick, & Barb Cain's profile

Dick, & Barb Cain

8693 posts in 4323 days

#15 posted 10-07-2010 12:46 AM

I’d hate to meet up with you in a dark alley.

I don’t think could run fast enough to get away from you. <(:O}&

-- -** You are never to old to set another goal or to dream a new dream ****************** Dick, & Barb Cain, Hibbing, MN.

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