Bill Fry Construction - Wm. H. Fry Const. Co. What a fun room.
In general, these are called floating shelves that have an interior structure which is fastened to the wall.
One clue that there could be an interior structure is that the shelf is fairly thick.
The extent to which the shelf is load bearing will drive the method used.
Here is an example of floating shelves that can carry a heavier load.
These are supported with interior metal brackets:
In general, these are called floating shelves that have an interior structure which is fastened to the wall.
One clue that there could be an interior structure is that the shelf is fairly thick.
If you search on how to install a floating shelf, you'll find a number of methods. Here is a youtube on how to do it:
The extent to which the shelf is load bearing will drive the method used.
Here is an example of floating shelves that can carry a heavier load.
These are supported with interior metal brackets: