In a message dated 12/20/2006 2:32:27 PM Eastern Standard Time, 
[log in to unmask] writes:

Does anyone know what the standards are for floor load capacity for stacks of 
12" vinyl and 10" shellac discs.

The standard for library book stacks is ~150 pounds psf.  I tried and failed 
to find anything on the internet that specifies vinyl and/or shellac.  I 
imagine it would be higher for the latter.  If there's an official document or 
study out there too, it would help convince the architects/engineers that this is 
an important issue.

I may be missing something here, but how does the psf spec depend on what is 
causing the p?  Which is heavier, a truck carrying a ton of feathers or a 
carrying a ton of cement?

I would think that the loading for shelf stacks would be independent of what 
is on them and the library specification would apply.

However, as all the other comments imply, it depends entirely on the type of 
construction of the building and flooring.

Mike Csontos