I have a two-story house. I want to put flooring in the attic to use for storage. I can't put weight directly on the floor joists due to the expansive soil and the house movement. So far I have been able to suspend 2X10's on the uprights of the walls. Now however I have a new problem. The span is too long for the 2X10's. I have heard of a system using the ceiling as the supportive structure and attached to the floor joists to lay the flooring on. I do not understand this system and also would like to know if there are any other options to resolve this problem.
I don't understand your post very well. You state that you cannot put weight directly on the attic floor joists due to expansive soil. So you plan to put flooring up, presumably supported by the joists, but maybe you want to hang the flooring from the roof rafters? Or possibly you are hanging the 2x10 to support the flooring off the walls? I would love to see some pictures, as I am having a very difficult time picturing what you have done and what you propose to do.
I have never heard that you cannot put storage on floor joists because of expansive soil. I have certainly heard about problems in basements, but this is the first time I have heard about attic issues. Perhaps you can fill us in and explain exactly why the expansive soils make it impossible to directly support weight on attic joists.