tmurray
SAWHORSE
Some hangers for end bearing of the joists in the second photo as others have said.
Generally you would want to fastened the joists together a little more regularly than at half spans if you want them to act as a unit, but this may not be required if the 2x10 are of the proper span. Personally, I would nail at 8" spacing to make sure they flex together.
Generally you would want to fastened the joists together a little more regularly than at half spans if you want them to act as a unit, but this may not be required if the 2x10 are of the proper span. Personally, I would nail at 8" spacing to make sure they flex together.