Design for a Rooftop Fitness Center 2

[Ggash]

Hey everyone, I have a unique design I'm working that maybe someone can provide an answer or suggestion to:

I'm designing a 4-story, wood structure apartment complex, and the client wants to put a bar and a fitness center on the roof. I have looked in ASCE 7-16 and there is a live load designation for gymnasiums of 100 psf, but I've also found in certain articles mentions of 125 psf or 150 psf live loads for fitness centers. I just wanted to know if anyone has designed a similar situation, and if so, what live load they used?

Thanks,
Greg

 

[ProgrammingPE]

Eng-Tips Thread: Weight Room Live Loads

Based on ASCE 7-10, Gymnasiums require 100 psf.

However, section 4.3.1 indicates that you, as the designer, must design the floor for "the maximum loads expected by the intended use or occupancy..."

Therefore the correct thing to do is:

1. Research the weights of the types of equipment anticipated to be used in the room.
2. Calculate their effective area load as compared with the 100 psf live load.
3. If the equipment results in a load larger than 100 psf, apply the equipment loads in appropriate areas based on their intended positions/placement and then apply 100 psf around them in other floor areas.
4. If the actual area of the equipment is unknown, or is known to change, you may have to design other areas of the floor to the higher load than 100 psf.
5. If the equipment results in a load smaller than 100 psf - use 100 psf everywhere.

The above is what I would do, based on the fact that this is a situation where my engineering judgement must come into play - and realizing that my judgement should be at least based on some data from the owner and the equipment manufacturers.

Also, make sure you check for concentrated loads and floor vibration.

Structural Central

http://www.structuralcentral.com

http://www.youtube.com/channel/UCOj2mXXf3ZbZtgxTc6BtkGg

 

[Ggash]

Great, thank you!

I definitely was going to treat the weight rack as a concentrated load, but I didn't know exactly what to consider for the fitness center as a whole.

Thanks,
Greg

 

[1503-44]

He wasn't joking about checking the vibration.
Nothing worse than resonance of the floor and the music.

 

[SwinnyGG]

I definitely was going to treat the weight rack as a concentrated load, but I didn't know exactly what to consider for the fitness center as a whole.

Might also need to consider things like squat racks dropping hundreds of lbs onto the floor from 6+ feet... I'd imagine designing an elevated floor for a gym could be nasty work.

 

[Ggash]

thankfully there is no squat rack, mainly treadmills and elipticals. There is one weight rack holding dumbbells, but a squat rack would add a new level of difficulty, especially 4 stories up on a 20' span for wood joists.

 

[phamENG]

Ggash - there isn't one now. But what happens in 5 years when their lease is up on the equipment and the new sales guy convinces them to change the equipment set? I doubt they'll check your drawings to make sure they can do it - they'll assume that it's a weight room so they can put typical weight room stuff in it. I would do 150psf and vibration. If you're using floor trusses, use strong backs and use them often. Bumping up your sheathing to 1-1/8" and keeping your truss spacing down may not be a bad idea either.

 

[Tomfh]

Vibration is a big issue. I went to a gym that bounced horribly, and a physiotherapist I visited recently had very bouncy floors due to these specialised treadmills that obese people used.

 

[CTW]

Check WoodWorks Link to see if they have any documents relevant to fitness center loads and vibration.

 

[XR250]

Bumping up your sheathing to 1-1/8" and keeping your truss spacing down may not be a bad idea either.

I second the 1 1/8" sheathing. Trusses hate random point loads on their top chords as they flex between panel points.

 

[XR250]

Never seen a squat rack in an Apt. complex gym. Seems like a big liability issue.

 

[Ggash]

Thank you all for your comments!

Vibration is a top check for the floor for sure, I also am about to reach out to a truss manufacturer and seeing which trusses are usable for the required loads and spans and at different spacings. And I also am writing a narrative of specific equipment that will not be allowed ever due to design limits: a squat rack being one of them. I doubt they'd ever try since a rooftop fitness center, but I don't want the option open.

 

[phamENG]

Ggash - remember, any free weight set up - bar bells, dumb bells, etc. - have the opportunity to (and will) result in heavy impact loads from about 4' above the floor. So unless they're going treadmills and exercise machines only, you'll have trouble controlling it.

 

[Ggash]

they are planning to add a rack of dumbbells, unfortunately. I am going to state a limit of dumbbell weight the rack can hold and run a 150 psf live load, plus an area load of the other equipment they plan to use. I'm ultimately trying to convince them to move the fitness center to the basement floor, but that would require a change in the plans and the client is wanting a DD set in two weeks, so I don't know if that is an option. At the least I'm trying to convince them to change the framing from wood to steel, especially since wood cost is so marked up that steel framing might be even in cost if not cheaper.

 

[phamENG]

Steel has gone up, too. And if you do steel do rolled shapes. I spoke to one of my fabricator clients a couple weeks ago and lead time on open web steel joists was out to January.