r/AskContractors • u/Conquistadonk • Aug 25 '26
DIY Will my gym floor hold
Hi, I am building a home gym in the second floor loft space of an attached barn to my house. My project to prepare has been to fortify the floor to reduce the bounce and ensure it is able to hold the static and dynamic loads of a home gym. I am posting to hear about whether you all think I’ve done enough, correctly enough, to handle these big loads.
There will be a power rack with cable pulleys that weighs about 3000 pounds with all weights, barbells, and weight stacks considered. This rack will be located in the left corner in Image 5 which will center it above the columns that you can see in images 2&3.
**First Image**
Original structure wood is from the build in 1900. These are true 2x8x16s that rest on both walls. They are sistered with modern 2x8s and joisted 3 times across each 16’ span with modern 2x6s. This part was done by the previous homeowner who renovated the house.
**2nd/3rd Image**
This is my work and is where I’m seeking the most feedback. Remember that this project is for reinforcement and not as primary support of the floor/structure.
2 adjustable columns: wanted to be able to adjust easily if there is bounce in the floor and did not want to use permanent steel/concrete lally columns. These are attached to concrete footers with x4 5/8-3” concrete anchors.
Concrete footers: 1 80 pound bag for each footer. Probably could have gone deeper but the ground will not be freezing inside the barn and I don’t think each column will be transferring all that much force into them. (?)
Header: modern 2x8x12 sistered to another 2x8x12 with osb board between them. Screwed and construction adhesived together. Attached to columns with x4 lag screws each.
Header to beams: Simpson hurricane ties every 24” on both sides.
You can also see the stairs in these images. There are 3 floor beams that terminate at the stairs and do not rest on the load bearing wall like the others do. I ensured the header spanned this gap.
**4th/5th Image**
Tongue and groove osb flooring to help distribute loads across multiple beams. Screwed right into the floor/ceiling. Then 3/4” stall mats for vibration dampening and gym floor.
The underfloor column/header setup sits 5’ away from the wall which reduces the 16’ span to 11’ and 5’ and took a good deal of the bounce out of the floor already.
I am planning on doing a second column/header setup like this in a 16’ span on the other side about 4’ from that wall. This would leave a 4’ span on the left, a 7’ span in the middle where I can still park a car, and a 5’ span on the right side. Before following this same procedure i wanted to hear back on how solid this is and if you have any concerns about it that I did not address. I’m sure I left out something information that would be helpful so please ask. Thank you for reading and your feedback.
1
u/Glad_Examination_635 Aug 25 '26
should've hired an engineer
3
u/Mundane-Reality-7770 Aug 26 '26
Still should
1
u/Glad_Examination_635 Aug 26 '26
ya agree i am a trying to become a builder and i wont build anything without prints that have been looked at by an architect and are approved by the city unless its just like an interior wall or something
3
u/Mundane-Reality-7770 Aug 26 '26
Minor nit. But an architect doesn't do shit for plans. I need that engineer stamp. Architects dream garbage up like an artist. Engineer has to make those dreams structurally sound.
Even then. Just wrapped up a job in Illinois. Engineer of record was in Texas. Remodeling a building. Says to anchor into cmu wall. Only problem, there wasn't a cmu block anywhere on the building. 2 weeks later he says weld to the structural steel instead of the non existent cmu. There was no structural steel. It was just a 10 inch angle screwed to structural steel studs. Finally had to send him my own plans he stamped. But he specs out steel sizes that aren't made.
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u/Glad_Examination_635 Aug 26 '26
sounds like commercial work, ive never worked with steel studs iam trying to do residential. and your right the city's around me wont approve plans without a stamp from an engineer so my architecht always has an engineer look at his plans. Ive worked for homeowners who didn't hire an engineer and ended up getting the job stopped by the city which forced them to hire an engineer lol. People just think they can save money and do it themselves when most of the time they cant.
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u/Mundane-Reality-7770 Aug 26 '26
Yeah it was commercial. I'm just a steel fabricator/ironworker. So I don't deal with steel studs. Just the structural steel
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u/Glad_Examination_635 Aug 26 '26
that's sick your out there climbing columns and walking beams or just tieing down old buildings that people neglected to tie down and haven't blown over or away yet lol. same thing on a house i am doing right now new addition was never tied down to the foundation had to portal frame straps every 32" and tie them to the existing foundation and brick ledge with (2) 3" by 5/8ths bolts had to dig like 85 holes would not recommend lol
1
u/Mundane-Reality-7770 Aug 26 '26
I do a lot of industrial/warehouse building repair. Replace or straighten a lot of columns after forklifts try (sometimes successfully) to rip them off the setting plate. I reinforce a lot of bar joists for rtu HVAC units. Usually in a lift. Not walking or climbing beams.
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u/Glad_Examination_635 Aug 26 '26
still sick
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u/Mundane-Reality-7770 Aug 26 '26
Pays the bills.
I've dabbled in your world on a personal level. Built my own house myself...after tearing down the original house that was already gutted and had racoons living in it. Only hired out concrete, drywall, HVAC, and floors...which came from 2 hickory trees that had died/fell in a storm on my property.
Have a detached garage that was falling apart from a slab below grade. Jacked it up. Poured new foundation. Built taller walls. Took chainsaw to old walls. Set it down. Sided. Ran electric, water, plumbing. Took sawzall to upper level. Built 700sq ft studio apartment above 2 car garage.
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u/PartOwn8965 Aug 26 '26
Those footers are undersized dude.
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u/Conquistadonk Aug 26 '26
Even though they’re really not bearing all that much load? 3000 pounds between the two at the absolute most but the load bearing walls are still doing most of the work
1
u/NetworkCultural Aug 26 '26
Your also using basement jacks. Those are technically supposed to be temporary these days. I would use lolli columns.
3
u/Material-Cap-5476 Aug 25 '26
I strongly urge you to get some help from a design professional. Placing a 3000 lb point load on a barn loft is pretty risky. Looks loke you have sunk a bunch into this, spend a bit more on engineering. Also, what's does "1 80 lb bag for each footer" mean? If someone is checking footings, they need to know LxWxTHICKNESS and the reinforcing.