Playground loading on elevated slab 3

[ceci1628]

I am working on a renovation project where the client wants to put a playground at the top level of a parking garage. I am limited in the live load capacity of the structure, and I need to account for playground substrate dead load. I cannot use the 100 psf assembly load. What live load have you used for playground area and how do you justify it?

Thanks in advance.

 

[SlideRuleEra]

Perhaps a classroom at 50 psf. A little Googling found this has considered by others:

https://www.linkedin.com/grp/post/117554-5924003503180623876

http://www.SlideRuleEra.net

http://www.VacuumTubeEra.net

 

[manstrom]

I would consider it a public assembly area - 100 psf.

When I am working on a problem, I never think about beauty but when I have finished, if the solution is not beautiful, I know it is wrong.

-R. Buckminster Fuller

 

[ceci1628]

Thank you both. I will contact the permitting office today and see what they think.

 

[Signious]

I would do 100psf assumed live load as a commercial assembly area, and do hand calcs on the dead load based on actual material weight, then factor accordingly.

 

[thaidavid40]

You'll likely have considerable dampening dead weight anyway, but I would also give at least a cursory check for vibration from rhythmic excitation from group exercise.

Thaidavid

 

[Guastavino]

If you talk to the permitting office, I'd try to get something in writing from them. Something funny happens to our memory during litigation.

As for the playground, I would consider it 100 psf. For the 2009 IBC the following are 100 psf

1. Yards and Terraces, pedestrians
2. Roofs used for roof gardens or assembly purposes.
3. Gyms 100
4. Dance halls and ball rooms

Meanwhile, Parking garages are typically designed for 40 psf. I would be skeptical it wouldn't work until proven innocent. Meanwhile, I would also not feel pressured to get a lower live load just because it's what your client wants. It's tough not to feel the pressure, but at the same time, if you educate them on your findings and they are upset, it's probably not a client you want to work for in the long haul.

 

[ceci1628]

Thank you all. I will perform a vibration check, good call thaidavid40.

The permit office did not give a straight answer and I didn't expect them to. They defer to us to make the engineering judgment. One of the suggestions was to use 75 psf for something between a classroom and a gym. We're going to try this knowing it may or may not get approved later on.

 

[Guastavino]

Spatrum,

One last thought. Just because it gets approved by the building department doesn't mean you are in the clear. The building department isn't responsible for checking everything. In other words, if you are OK making the 75 psf assumption, then make sure you are confident to defend it. I doubt that saying that the building department approved your plans would be an adequate defense if anything went wrong. But again, it's your judgment call, just be confident you can defend your decision. I'm not saying it's right or wrong, but the building department approval status of your plans shouldn't be a factor in your decision.

Imagine that you aren't' following some provision of ASCE 7 because you don't necessarily agree with it. For example, the 1.9 factor for the wind loads on rooftop units. I personally think it's a major fudge factor to CYA the code folks. So let's say I submit a drawing for a rooftop unit addition and omit the 1.9 factor and then something bad happens. If someone reviews my calculations and sees that I omitted the 1.9 factor they can grill me on it, whether right or wrong. Now, if I say "well the building official didn't comment on that", then I would look ridiculous.

Again, all I'm saying is make sure YOU are comfortable with the decision. I would send my kids to play at a playground designed for 75 psf, but I wouldn't design one for 75 psf, I'd use 100. I also would stand next to an RTU in a high wind that was designed without the 1.9 factor, but I wouldn't design one that way. The reason is that while I live in the real world, lawyers don't.

Nick

 

[cb1331]

Agreed regarding 100psf. I would consider a playground an assembly occupancy.

 

[ceci1628]

njlutzwe, thank you for the feedback. You have made some very good points.
Thanks to everyone.