I built a 18ft wide x 10ft off the house deck. Deck has double 2x10 rim joist with 2x8 joist 16in on center with 4 6x6 post that are notched and have 14in footings. I built this deck with a shed roof design in mind, but I mocked up the shed roof and not a fan of the look so I’m trying to switch to a gable roof to match the home. My question is, what is the best way to attach the double 2x10 headers that attach to the side of the house that will support the weight of the roof. I will be using 2x6 rafters and putting a metal roof on it so it will not be a lot of weight. Pic attached is the deck and mocked up shed roof. Can i add a 6x6 post to the middle of the rim joist to help support the double 2x10 header beam for the roof? I was thinking that would allow me to attach the 2x10 to the house without the house holding the load and the 2 6x6 would hold it.