To secure the lag bolts to the joist, it looks like you used a drill rather than a socket wrench. If so, could u confirm which drill attachments are needed for that?
It would be a 5/16" socket driver, or 5/16" nut driver. Add "impact' to the name if you're using an impact driver instead of a drill. An impact socket driver will be built to take the abuse of the "impact" which a drill won't do. Impact driver with socket will be way easier to drive a 3" lag bolt into a 2X4.
