Will my floor support a gym?


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Old 02-28-05, 05:22 AM
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Will my floor support a gym?

Hello Friends,

I just moved into a well-built Cape Cod, built in 1939/1940.

I have a home gym that will not fit (too tall) in the basement, and I would like to install it on the 2nd floor spare bedroom. Characteristics as follows:

It's mainly freeweights (a smith machine, squat rack, etc):
http://us.home.lifefitness.com/content.cfm/smith

It's a weight cage/rack with 4 feet, about 4'x4'. The weight "trees", as we call them, are built into the Smith machine for storage when not in use.

Total weight (gym and weights & a 200lb 8'x8' rubber mat over a hw floor): 1500-2000 lbs, mainly distributed between the two rear feet (about 4 feet apart).

Q1: Do I need to reinforce the joists?
Q2: If not, where is the best place to situate the bulk of the load? Near the window, or closer to the opposing load-bearing wall?

I have not moved into the house yet, and I want to tell the movers to move this to the right location the 1st (and hopefully only) time.

I've also requested (through this website -- "Need a Contractor") the services of a structural engineer, but if you think that's really not needed, please advise; I move in 1.5 weeks!

Thanks,
Matt
 
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Old 02-28-05, 06:46 PM
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i would contact an engineer. you dont know what the joists are capable of supporting. there is a real chance they are woefully undersized, which could be dangerous.
 
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Old 03-01-05, 09:06 AM
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Originally Posted by clardl
i would contact an engineer. you dont know what the joists are capable of supporting. there is a real chance they are woefully undersized, which could be dangerous.
Thanks, I've got a few names of engineers already, and I will call them today.

In terms of any/all national codes (forget my city's code for now), what should the floor be able to support (live, static wt for now... I expect bounce when I'm doing my exercises, especially with a 300+ lb bar on my shoulders during squats, for example), based on the aforementioned description of the house?

In the basement, I've noticed a very long steel I-Beam used as the spanning beam for the 12' 2x12 floor joists (on each side, tounged into the ibeam). What do you think is used for the 1st floor headers (2nd floor beam(s)) and the 2nd-floor floor joists? Based on your ASSUMPTIONS (no, I will not use your assumptions in practice), what loads (both psi & total distribution) can my floor support? It would be nice if that were the same steel ibeam as found in the basement, but I seriously doubt that.

I'm a woodworker & finish-carpenter, but certainly not (yet, at least) a carpenter, so please forgive my ignorance with regard to rough carpentry.

Thanks,

Matt
 
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Old 03-02-05, 05:32 PM
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Nowadays residential floors are designed for 40 lbs per square foot live load for all rooms except for bedrooms, which are designed for 30 psf. standard wood framed floors also include about 10 psf of dead loads to account for the weight of the framing.

if you do the math, when you spread the weight of the nautilaus over the footprint, it works out. The problem with that logic is the load is not spread out.
 
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Old 03-02-05, 08:02 PM
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Originally Posted by clardl
Nowadays residential floors are designed for 40 lbs per square foot live load for all rooms except for bedrooms, which are designed for 30 psf. standard wood framed floors also include about 10 psf of dead loads to account for the weight of the framing.

if you do the math, when you spread the weight of the nautilaus over the footprint, it works out. The problem with that logic is the load is not spread out.
It does not work out!
2000 lb s supported on the 2 rear legs 4 ft apart my be considered as 2 1000 lb loads, each supported on an area of about 1 sq. ft. This is way too much and is what is called a point load. Definitely you need an engineer.
 
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Old 03-03-05, 05:23 PM
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The point of my statement is that the useable footprint of this piece of equipment is around 8'x8'. sixty four square feet of 40 psf load is approximately 2600 lbs. While there will be large concentrated loads at the two legs, the load on the surrounding area is very little, due to the nature of its use.
This conditon is the similar to installing a waterbed in a bedroom, which weighs at least as much as this piece of equipment. Typically, nobody thinks twice before installing a waterbed, which weighs more. The difference is the loads in this case are concentrated, which poses problems, which is why i reccomended he contact an engineer.
 
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Old 03-03-05, 08:28 PM
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Thanks for all your help on this!

Well -- I had a structural engineer visit the property today, and we discussed a few options.

1. There is no requirement for me to use the gym as it was intended. In other words, the storage of weights (plates) can be distributed all around the room, with multiple weight trees, this limiting the point loads. I knew his all along, but I didn't want to listen to my inner voice.
2. It so happens that there are tightlly adjoining hallways on the 1st floor such that: if I were to support them properly from the basement (only 1 wall is current supported directly by a post in the basement), the postion of these 1st-floor load-bearing walls would allow a direct transfer of load from the 2nd floor all the way to the basement. This adds more columns in the basement than I had wanted, but I'll do what it takes so that I don't fall through the floor doing squats!
3. Before doing any of this, I will spread the load as much as possible with a rigid platform on the 2nd floor bedroom. Personally, I doubt I can construct a platform rigid enough to distribute the load evenly, but I need to protect the finished wood floor anyway, so every little bit helps, I guess.

The engineer is spec-ing out materials for me now, but his sketches looked pretty straight-forward.

Hey - where do you guys get steel I-beams? Do you order this online? I was wondering, since this is a very, very low-volume order I'll be making. any tips would be appreciated. Of course, I first have to wait for the specs.

fyi -- the engineer was confident that the 2nd floor was constructed similarly to the 1st floor -- using 2x10s, and he also gave the estimated 40psi life load. I'm not sure if they are spaced 16in-oc as in the basement, but he's pretty sure that they're 2x10s based on the difference in ceiling heights between the 1st and 2nd floors.

Thanks!
Matt
 
 

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