How to add surface loads to seismic weight?

Hi,

I modeled a floor using surface elements and loaded it with surface loads (for my dead load, etc). Now I need to capture the dead loads into the seismic weight when I do my seismic load definition (IBC 2006). How do I accomplish this?

I understand that if you have a plate element loaded you can use "Element Weight" then "pressure". Can these commands be used for surface elements as well?

Thanks,