"Andy Hill" wrote in message
I'm probably visualizing the problem wrong, but why not basically build a
"deck"
using 2x4s running perpendicular to the bottom chords of the trusses (with
the
2x4s screwed into the bottom chords)? You could probably even get by
using
widely spaced (say, the width of a 2x4) decking boards, since you just
want to
have something to walk on and stack boxes on.

The trusses are designed to hold up a roof, not a floor. You should not
build a floor on them or hang much weight on them.