Loading:help

[longisland]

Hi all,

I can't seem to find the ceiling load for office building. i.e, the loading from the M & E srevices such as cable trunking or ducting, chiller pipe, aircon ducts, sprinkler etc.
What's the ball park figure?
It's stated in UBC that no live load reduction factor is to be applied in office filing areas. However, the building layout is subject to change due to change of tenants, that means the file storage area may be shifted. Moreover, the imposed load is lighter for general office areas with respect to filing areas. Any comments?
If the tenants decide to change the layout of the floor and that change causes structure damage, who's to be blamed? E.g, shifting of filing room?
I ignored partition load (gypsum plastered boards) because I believed this load has been taken into account for in the imposed load similar to furnitures.

Thanks for the input in advance.

 

[ishvaaag]

10 to 20 psf are sometimes taken as service level loads of the mechanical services plus ceiling; other than that one can make actual estimates of the weight and use if less.

Respect the allowable live loads in any area, you must instruct these be posted in accord with your design if you think changes violating it will be happening. Specify such signs in yor project, and include the values in the Book of the Building or anything so if where you live exists.

That way you may combine adapatation to the wishes for economy of the owner to some protection of the liability of the designer.

Respects embedding partition loads in live ones, normally one does not makes so in Spain. They may be considered a uniform surcharge to some extent, but if heavy must be considered as line loads. If your code other thing permits you should be able to ascertain.

 

[jheidt2543]

longisland:

With all due respect to Ishvaaag, in my experiance I've seen mechanical system loads in the range of 3-5 psf used over the whole area. Where you have to be carefull is when you have a concentrated mechanical load, such as a large fire protection main (large is bigger than 6" diameter). Those situations should be investigated individually. Generally speaking, the 3-5 psf covers most plumbing, ductwork and electrical system loads. Once you look at a few cases and the effect they have on the structural system, you'll have a pretty good idea of what loads are important.

Many codes also address this question and you should look for those requirements in the code that affects your building.

 

[LPPE]

I agree with ishvaaag. Mechanical, electrical, plumbing, plus ceiling is generally around 10 to 15 psf.
Your name would indicate perhaps the job is in New York? Why the UBC code, then? The New York State building code I'm sure spells out what live loads to use for office buildings, including partition loads. Some building codes require that you use the office live loading PLUS a partition load. In my area its 50 psf plus 20 psf partition.
In summary, I would figure the worst case (storage or office) and desgin the whole structure for that. That way, the client can change layouts whenever/whereever he/she wants to without a second thought.

 

[JAE]

We usually use 5 psf for Mech/Elec items within an occupied space such as offices, hospitals, schools, commercial, etc. Normally you only have ducts, hung lighting, electrical conduit, and other cabling. Agree with jheidt2543 that larger pipes such as 6" dia. and any special mech. equipment should be investigated as unique loads.

Ceilings - depends on what you have. A typical hung acoustical ceiling rarely weighs more than 2 to 3 psf.

 

[Ron]

I usually use 4 psf for mechanical, 1 to 2 psf for drop-in ceiling (more for hard ceiling), unless something out of the ordinary.