Seismic Force for Interior Partitions on One-Story Building

[abusementpark]

How do you typically account for seismic force associated with interior partitions on a one-story building? The interior partitions are gravity supported by the ground floor, but typically require some attachment to the roof for lateral stability. So it seems like I should assume half of the partition weight gets transferred to roof in a seismic event. It would be a pain to tally up the total weight of all partitions, which may be subject to revisions by future tenants anyway.

Are most engineers just adding 5psf or something like that to the roof mass to account for this? Or is it something that gets neglected?

 

[wannabeSE]

Typically, 10 psf is added to the seismic weight for elevated floors and 5psf for roofs. For partitions, 1/2 the seismic weight is applies to the floor below and 1/2 to the floor above. The 10 psf comes from ASCE 7-10 section 12.7.2.2 .