reinforce roof trusses

huangyhg

reinforce roof trusses
i am wanting to reinforce my pre-fab roof trusses so that i can add a storage area in the attic of my garage. the span of the trusses is 30 feet; they are spaced every 2 feet. the garage is 30' x 30'. i have thought about adding a steel beam across the center of the garage, supported at each end by the wall, and 2 metal posts spaced 10' in from each wall. i would like to place a plywood floor in the center of the attic to store things. does this sound o.k.? anyone out there with a better, less expensive, or easier solution? thanks, gary  
gary,
i assume you are considering adding the steel beam to support the trusses at midspan.  this is not a good idea as it is likely the trusses were not designed for a point of bearing in the middle (some truss styles can take it, some can't).
for such a modification, i would suggest that you get a local structural engineer to look at it.  he can guide you in the modifications and have them meet local codes and standards.
it is relatively easy to modify a truss in such a manner that forces and stresses are redistributed in a dangerous manner. i'm sure you don't want that!
ron
i agree with ron.  at first glance an additional support might look like a good idea, but if you start putting   
i second both opinions. i had the opportunity to strengthen a o.w.s.j. when i analysed using a temporary support in middle. every thing gets screwed up. i vaguely remember that support at top chord only was reasonable. than i added angles on web and rebars on t & b chords. gettonna bottom line is "it is better to structurally analyse the real situation"