Contractor told me that he would be able to install 5′ wide sliding door or a regular door with the original header and new 2×6 studs on each side. The opening of concrete walls is 64″. The header supports 4 joists. The header is 9″ wide, there is 8″ from the top of the header to the top of the door (called casing?).
Any concern about the size of the header and support? Any comments are welcome.