Before the fireplaces could be installed this week, we needed to build the interior firebox framing and add a chimney band. The interior framing was built once before, but after analyzing the living room layout, felt it needed to be set back into the SpeakEasy room wall to recess the footprint. Now it extends the perfect amount and will have only a 4" side reveal once the built-in bookshelves are installed. As for the exterior fireplace, this framing was good to go with the exception of adding a band around the top of the chimney. This is a detail to help prevent wood rot from the corners and help shed water once the cap is on.
When working with headers, the full size support beam is called a King Stud and the interior shorter beam is called a Jack Stud.
All wood is actually 1/2" shy of it's labeled measurement. For example a 2x4" board really measures 1.5x3.5"....as if building and math isn't fun enough:)