Live load for museum floor 2

[Lutfi]

I can not find direct reference for second floor live loading of a photography museum. Does anyone have a reference that they can cite for me?

I am between two values, 50 PSF and 80 PSF. Any thoughts would be appreciated.


Regards,
Lutfi

 

[dik]

For museum floors, due to the assembly nature of these, I would use a LL of 100 psf minimum unless stipulated otherwise by the owner. For storage areas and filing areas, the load could easily be in excess of 100 psf.

$.03(CAN) Dik

 

[Lutfi]

dik,

Thanks for the quick input.

For the storage area I used 300 PSF because they have a storage compactor.

100 psf sounds good at face value. However, I do not want to over design if not necessary.

Do you have a code reference?




Regards,
Lutfi

 

[JAE]

Lutfi - I'd agree with dik on this one. museums many times have "shows" or events and these qualify as a public assembly area. In addition, sculptures and other museum items can be very heavy so 100 psf isn't excessive.

For a photography museum...do you have photographic equipment on display? You might want to find out what the display layout is planned and try to get a handle on true weights.

 

[SlideRuleEra]

Lutfi - The museum area that you describe and the reading room of a library would seem to have a lot in common.

ASCE 7-02 gives Library Reading Room live load as
60 PSF (Uniform) and 1000 lb (concentrated)

http://www.SlideRuleEra.net

 

[JAE]

I think a library reading room is generally described as the area where the tables and chairs are along with minor shelving for "special" displays...i.e. not the stack areas. I would think a museum would be heavier.

 

[SlideRuleEra]

JAE, I see your point. Here is a more direct reference, the British Standard Code of Practice gives 80 PSF as a standard for museums, although this writer says that may not be enough

http://www.ihbc.org.uk/context_archive/70/floorloadings/floor.html

(Museum loading discussed just below the halfway point)

http://www.SlideRuleEra.net

 

[JAE]

Slide...

Yep - the article also includes this:

[red]In one example, a museum building was to display a fine collection of bone china in glass cabinets that were to be fixed to the walls and floors. Even taking account of the fact that the space between cabinets could easily be crowded with visitors, it was shown that the floor loading was less than half the 4.0 kN/sqm suggested by the British Standard. A somewhat lower value was therefore used and the amount of structural intervention was dramatically reduced, without compromising the safety of the visitors or of the building.[/red]

This sounds like the studies I've read where office loading (usually designed at 50 psf) was found to truly range around 10 to 12 psf in actuality.

However, for any floor, we as engineers are judged against the standard of care - what another reasonable engineer would do - so most engineers I know are naturally conservative in their designs and would use the code required load or even higher if they suspected different potential uses for the floor - so in a museum, I can certainly envision a large group of people gathering for a party or an exhibition with speakers, etc. - and that sounds a lot like "public assembly" to me (i.e. 100 psf).

 

[SlideRuleEra]

Ok... you convinced me, there could certainly be a large group of people, shoulder to shoulder for a tour, and that is 100 PSF (for folks my size anyway)

http://www.SlideRuleEra.net

 

[dik]

JAE:
Baker's steel skeleton has reference on actual loading within office space, but conditions may have changed since the original publication. The results mimic your 10-12 psf... they have a bit of a breakdown based on area...

Dik

 

[dik]

I don't have my copy of the NBCC at home, but most assembly areas without fixed seating/tables, etc. are 100 psf...

It's been my experience that the cost for the added loading is a small additional item... the real economy is the selection of the framing system. Your and JAE's experience might be similar..

Dik

 

[emmgjld]

Depending on the type of museum, I believe the Live Loads could be expected to range from as low as 50 psf to well over 100 psf. I would not expect a photography museum to require more than 70 psf, unless a large number of glass plates are anticipated (except for storage areas).

In my experience, Performance is usually the issue. I have not dealt with any fall down floor failures, even when the floors were obviously overloaded. Floors which 'bounce' 'vibrate' or 'just do not feel right' are a common occurance. If the display cabinets rattle when people walk around or when the distracted boy jumps up and down, It could be perceived as a failure.

Very interesting how little specific guidence can be found for what should be a small problem. We are accustomed to having this all laid out in a code or standard. Good discussion.

 

[Lutfi]

Thanks for the debate and great exchange of ideas. This is what I like about this forum.

I have been in practice for over 23 years and my judgment tells me that 100 psf is the way to go. One will never know what the client may want to hold as a function down the road.

For now, it is a photography venue to display various pictures by the client’s photography students and professionals alike. Even hold regional shows.

I was leaning towards the 50 PSF but I convinced myself to use the 100 psf.

Good night to all.


Regards,
Lutfi

 

[Tomfh]

The Australian loading code gives 4 kPa (~80 psf) for museums. However it gives 5kPa (~100 psf) for areas susceptible to overcrowding.

 

[SlideRuleEra]

Just an interesting post script. This morning started back to work on my next "E-book" to share with you folks (scanning and making a .pdf out of 372 page "1923 Carnegie Pocket Companion")

Lo, and behold...
There are the (historical) City Building Law Live Load requirements for, you guessed it, "Museums"

1917 New York: 100 PSF
1919 Boston: 100 PSF
1920 Cleveland: 125 PSF
1914 Pittsburg: 200 PSF

http://www.SlideRuleEra.net

 

[Lutfi]

wow slideRuleEra...... I am impressed man.

Regards,
Lutfi

 

[jheidt2543]

One more thought on the museum floor loading. While the exhibits could be large and spread over a good sized area resulting in a relatively low psf loading, the EQUIPMENT used to move it in and out of the "show room" could be pretty heavy -- forklifts etc. with good sized wheel loads.

I vote for the 100 psf.

 

[Tomfh]

I wonder why Pittburgh was so nervous.

 

[Dinosaur]

Slide Rule,

Your graphic makes it appear you are pulling some important reference information from behind and below your waist. That brings to mind an expression I heard often in collage ...

 

[SlideRuleEra]

Dinosaur - Thanks for your interesting (and accurate) observation - time to make a change!

http://www.SlideRuleEra.net