Storage truss so I can store stuff in the attic...

[Vintage Veloce]

So I'm designing my new storage building, and I'd like to be able to use the attic to store stuff.
It was easy to request the designer allow for some space in the center of the truss by widening the base of the center web.

The question... its costs more to add structure to be able to support more weight up there. How much is enough? I think the engineer said this design would support an extra 120 pounds per truss. Extra, meaning, beyond the roof and truss weight, etc. That sounded pretty good to me... but maybe I didn't think that through, as I weigh more than that. On the other hand, I'm not going to put engines up there, I'm limited by what I can easily carry up a steep stairway alone. Of course, weight would be distributed to more than one truss by some plywood up there. Hmm. Comments?
Carl

 

[strutaeng]

the number that the engineer comes up with is based on many variables. Ask for a tighter truss spacing and perhaps a higher quality lumber, if available locally by fabricator.

You can always ask your engineer to design special trusses in the attic area.

Also, usually member capacities are given in pounds per linear foot or square foot.

One last note, if a room is ever labeled "storage" the IBC requires 125 pounds per square foot of live load, which will require a very robust framing system (think expensive).