please rate tj-pro ratings

[vato]

Can someone comment on how well this rating system is working out in real life?
I am just starting to mess around with it on a 22.5' span. It looks like l/720 LL defl typically gets a tj-pro 45 rating.
Code minimum I-joist floors don't feel that great to me (l/360), but am I "over engineering" with
this tj-pro rating system, especially for a rating above 45?
for example, tj-pro 50 is l/1000, tj-pro 55 l/999+ approaching zero

Also, it seems like once you start telling a client how subjective floor vibrations
are, it is difficult to sound like you really know how to design a floor correctly. I can still
pull it off, but it doesn't build the client's confidence in you immediately.

 

[jdgengineer]

I have never had a floor problem and we always design for TJI rating = 50. I can't comment on if it is over-engineering, but I agree the LL ratios typically is ~1000 as you mention and therefore have pretty robust ratios. Normally, it's not too big of a deal to meet. We usually have TJI 230 x 11 7/8 spanning ~16' or so. 18' or so and we transition to 14" joists. 22.5' and we would be using at least 16" joists. At that span, we'd try to break up the span with steel beams depending on the floor layout. Floors have always felt nice and stiff.