Bookstore Live Load

[psuhoo]

I am working on a project that will involves a University Bookstore. What is a good live load to use? I was going to use 150 psf (Library Stack LL), but I am thinking this is a little too conservative. Any thoughts?

 

[DaveAtkins]

Well, the University Bookstores I have been to have very tall shelves, like in a library, but the aisles between shelves are wider. Either use 150 psf LL, or calculate what you think it will be based on height of shelves, spacing of shelves, and people in the aisles. Of course, the local code official would need to approve this.

DaveAtkins

 

[JedClampett]

Code says 150 psf for libraries (which is likely to be conservative for a bookstore), but that's the minimum required. Use more if you think it's justified.

 

[BAretired]

For a library, 150 psf live load is about right. It could be much higher, given the worst conditions. Do not use less than 150 psf and confirm with your client the height of storage units and the type of storage. Magazines with heavy paper, such as National Geographic magazines are very heavy. Newspaper material is quite light, so it all depends on what is being stored, how high and width of aisle between storage units.

BA

 

[hokie66]

Not applicable except in Australia and New Zealand, but our standard makes a distinction between the reading room areas with book storage and the stack areas. For normal reading room height, it uses 4.0 kPa (about 80 psf). For stack rooms, it requires 3.3 kPa per metre of storage height.

 

[Ron]

For retail bookstores, floor space is more valuable than for a library...stick with the 150 psf...they'll find a way to use it!

 

[BAretired]

The National Building Code of Canada (NBC) also makes a distinction. We have minimum live loads of 2.9 kPa (60 psf) for reading or study rooms and 7.2 kPa (150 psf)for stack rooms. The Australian and New Zealand code is much better.

BA

 

[psuhoo]

Thanks for your input. Here is some more information why I think 150 psf is high. The owner is calling retail/bookstore space, I am think more along the lines of barnes and noble or similar. When I think of a stack section of a library I think of stacks about 2 feet apart, where as a book store is more like 3 to 4 feet.

 

[BAretired]

psuhoo,

Minimum live load for retail or wholesale space is listed in the NBC as 4.8 kPa. Using hokie's suggestion, that would be good for book storage up to about 1.5m (5').

It might be enough, but it is limiting on what the bookstore can do. It would be cheaper to provide for 150 psf now than to beef it up later on. Talk to the client. See what he wants to do.

BA

 

[SlideRuleEra]

psuhoo - Frankly, I agree with with the advice that you have received, 150 psf... but, for a moment take a look at some other options. Here is an excerpt of the appropriate chapter of ASCE 7-02 for reference:

http://civil.eng.buffalo.edu/CIE429/ASCE-7-02-Live loads -s04.pdf

If you don't use 150 psf for "Stack Room", then what?

1. "Retail Store, Upper Floor" 75 psf with 1000 lb concentrated load, perhaps?

2. "Library Reading Room" 60 psf, maybe?

3. "Office Building" 100 psf?

An unintended consequence of any of these choices is that you now have the option (read that as obligation, IMHO) to apply live load reduction. Probably not a good idea for a possibly marginal loading requirement.

Of course you could arbitrarily assign a number that excludes live load reduction (101 psf to 149 psf), but that may be your worst option from a liability viewpoint.

My intent is not to convince you of one choice or another, but I believe that you have received high-quality advice from the other members.

http://www.SlideRuleEra.net

http://www.VacuumTubeEra.net

 

[msquared48]

The client knows nothing of floor loading limitations, nor cares, but your liability insurance agent and attorney do.

Don't ever trust that the client will do what they say here. Stick with the code requirement of 150 psf so you can sleep at night when your imagination runs wild after reading this post.

The code is tanamount to a medical standard of care, and that is what we have to measure up to. Sadly, even that can be challenged though.

Mike McCann
MMC Engineering

 

[paddingtongreen]

I say you would be taking a big risk by going less than library loading. The people who will look to see what you have done are not the nice people you are dealing with now. The lawyers and the bean counters move in later and look for excuses to withhold parts of your remuneration.

In real life, depending on the arrangement of the stacks, some beams may see the full design load while others don't, it is the nature of stacks, high load areas next to low load areas. Design for 150psf but use LL reduction if applicable.

Michael.
Timing has a lot to do with the outcome of a rain dance.

 

[msquared48]

Can't use LLR for any live load in excess of 100 psf.

Mike McCann
MMC Engineering