Hazarding a guess it looks like it might be bolted to the frame. If you can get underneath, do you see the other end of those bolts? I'm curious if it might be structural in a way.
they are 9/16th heads, i backed off one, and are surprisingly long, frame is steel though, so a bit confused on that. everything is covered underneath with vap. barrier/insulation between frame rails. *forgot to mention threads are wood threads
1955photo t1_iy5jsji wrote
Those look like bolts holding the posts to the frame. Those posts are load bearing. Don't mess with them!