GET that information to make an engineered decision...\

But 100 - 150 psf might not be out of order??

Thanks Mike.  

It's a gov project in RFP phase and they are slow to repsond to RFIs.

 

What is the floor structure made up of?  300-400 lbs. as an impacting point load on 3-4 sq.in., falling from 6' might not be an inappropriate loading, when some big horse drops a set of weights.  This should be applied to a plywd. sub fl. btwn. joists or to a single joist, as well as to a conc. slab.  You might also have a whole new set of floor vibration problems with several people on running equip. at the same time.

DHKpeWI,

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.

 

Here is a ilnk that states 150 psf live load should be used.

Garth Dreger PE - AZ Phoenix area
As EOR's we should take the responsibility to design our structures to support the components we allow in our design per that industry standards.

• http://www.wbdg.org/design/physical_fit.php

woodman88 - good link.

I would say that my suggested method above (100 psf with attention to specific weight equipment) could be acceptable based on the IBC but using 150 everywhere would be a valid alternative.

 

Thanks all.

 

The overall floor loading is probably not really all that great.  A typically workout room is not all that crowded, and even if a powerlifter is lifting a max load, you are still well below 100 psf over the footprint of the lifter and bar.  250 lb lifter, 320 lb weights gives 870 lbs over a 3 foot by 5 ft area, or roughly 55 psf, not including the remaining open space around the lift area.

Commercial treadmills weigh in at 500-700 lbs, plus a user (up to 350 lbs.) with a machine foot print of 3 ft by 7 ft, so less than 50 psf.

A multi-gym weighing 3300 lbs takes a 13 ft by 16 ft space (15 psf) including weight stacks.

It is difficult to imagine the load in an exercise room exceeding 100 psf, but provision must be made for local concentrated loads resulting from the accidental dropping of weights which could occur anywhere.

BA

Our gym has the weight area upstairs and is bouncy when someone drops something heavy.  It damps itself fairly quickly, but you can certainly feel it when you're between sets resting/sitting on a bench.  

It's relatively new (~10 years) and is concrete construction.  Not sure if it's CIP or precast.  There is some precast in the building but not sure about the floor system.

It seems like I once saw a military specification/design guideline that included weightrooms in the table for its design floor live loads that we used as the "starting point" on a job till we had more specific information.

It was something my boss came up with and it's been too long ago now for me to remember the source or the number.  Though I want to say it was 125 or 150 psf. Does anyone know what I might be referring to?  

Well, sure the calculated load for the treadmill (per total area) is low, but the treadmill is actually supported by 4x 1-1/2 dia pads.   Total loads (impact and dead load (eqpt + heavy person)) are hitting the subfloor at only 3.14 x (.75)^2 =  7 sq inches, not 7 sq feet.  

Worse, the person is likely to be crowding one end, so most of his (her?) 250 -275 lb weight will be on only 2 legs, not 4.   

A dropped 250 lb barbell will hit on and 2x areas of maybe 4x2 sq inches each.    

That treadmill load (700 lbs treadmill, 300 lb person, weight distribution 2/3 to one end) will be 200 psi, on concrete which is good for at least 2500 psi.  The psf on the footprint drops to 1000 lbs/(3' x 7') or about 50 psf.  Also, note that at 250 lbs per leg, the effective point load is roughly the same as a 250 lb person standing on one foot.  These are VERY small loads.

ASCE 7-10 for "Recreational uses - Gymnasiums" seems to be the logical choice, at 100 psf.  At 100 psf, the unreduced load accounts for a sudden loading/impact premium of 100%, over the ENTIRE floor area.

Remember that parking garages are designed for 40 psf, even though the wheel loads can be upwards of 1000-1500 lbs each, and the point load design criteria is 3000 lbs., specified for jacking load (see the footnotes to the table.)  The design of the slab for point/small area loads if you desire or need to do so is far different from designing an entire floor for such a high load.