I've got an interior wall that turns out to have once been an exterior wall (which I discovered after removing the wallboard).
It was the gable end of an addition (circa 1940?) to which a wrap-around mud room was added (circa 1965?). The foot print is a 10ft square (circa 1940) within a 17 ft square where the two squares share one, common corner (hence a 7ft wrap-around on two sides). The existing, conglomerated addition has a hipped roof whose joists are supported by a stud wall that was erected parallel to the former exterior wall (t&g siding still intact!).
I want to remove this funky double wall (10ft long) to open up what is currently a 10' x 17' kitchen with two windows into a 17' x 17' kitchen with 6 windows and a double sliding door. (Yes, that's right, the mud room has four windows and a double slider.)
The 1940s exterior wall was framed in the balloon style, and is perpendicular to the 2 x 6 attic joists above (which are nailed to the sides of the studs instead of resting on a plate.)
Can I span the 17' (of which only 10ft are load bearing) with a single, wooden beam? It would have to be a least 8" wide to catch and support both the c1940 joists AND the c1965 joists. But, how thick (deep? high?) would it need to be? 8 x 8? 8 x 12? Or, must I resign myself to having a post at the 10ft point (which is supported by a masonry foundation that must have been reinforced during the 1965 renovation)?