I have a house where the previous owner added a room on to the back. It's about 16 x 20 x 16. I was planning on removing the add-on, but have thought about turning it into a covered patio instead. I've found lots of info on removing load bearing walls, but nothing that quite matches what I want to do - take out 3 exterior load bearing walls.
I assume that I will have to construct some headers, and I know it will vary depending on local code, but does anybody know anything about how far to space the columns?