Is it better to sister a 2x8 floor joist (cracked somewhere in the middle) using same size lumber or is something like 3/4 plywood better? Consider that both ends of the newly sistered joist won't rest either on sill plate or on the mid-span beam. Most likely, I will be using two pieces of lumber or plywood as sister joist to span 11 ft. If it is plywood, then should I sister it from both sides of original joist or one side is fine.
Lastly, since both ends of sister joist won't be supported by the beam/foundation wall, is it just waste of time and wont add any strength?