Teamcasa wrote:
Ask a competent structural engineer. Any comments made here would made
without sufficient structural facts.

OTHO, Having had to stiffen a floor in one of our dealerships, I boxed the
floor trusses with 3/8" plywood, glued and nailed. Made it very stout,
however I had no obstructions to deal with.

My engineer winced, shrugged his shoulders and walked off shaking his head.

Dave

As an engineer (but not structural) I know that anything discussed here
is not what I am going to base my decision on - BUT it can be a great
way to get ideas and help sort out some of the options. On purpose I
didn't give enough details for anyone to even start making calculations
so that this would be kept more as a brainstorming situation.

Of course - this isn't to add "needed" strength - just to reduce the
flex that is normal in any floor. (save maybe a poured on grade concrete
slab). Because this isn't necessary to keep the building standing I
feel a lot more comfortable with hill-billy style engineering grin.

Basically boxing the trusses was one of my ideas - with a few
appropriate cutouts where needed.

Thanks for the input!

Dan