Patio Roof Beam, Post and Pier Size

I'm considering putting in a patio roof attached to the house. It will have typical composition shingles to match the existing roof. I'm just doing some background investigation on costs, feasibility, etc. I'd like a hip roof (don't think that makes a difference) about 13 ft square. I was hoping to put up only two posts. I'm located in Central TX - freezing is not a problem.
I will build a deck under the patio, but will make it completely self-standing - the load from the deck will not need to be added to load on the roof posts. The deck will likely come before the patio roof, so I don't want to tie the two projects together. I might pour the roof post piers at the same time I build the deck.
Questions:
1) What size posts? I was thinking 6x6 would be enough (I know this needs to be calculated out). The posts will be about 9' long from the tops of the piers to the beams.
2) What size beam would be required between the two posts?
3) What size beam would be required from the posts to the existing wall header. Probably the same size?
4) It is possible or likely that the existing wall header will need to be beefed up? One beam will be right over a patio door and the other over a set of windows.
4) What diameter piers would be required for the posts and what depth?
I'll get an engineer, inspections, permit, etc, but I would like to have some background info before I talk to anyone. Or possibly rule out the project before I spend any money on it.
Hopefully, I didn't forget any pertinent details.
Thanks!
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Just pour some piers to build the deck frame off of. Then, put the roof on. Suggest 10X10 piers, flush with the subfloor framing outside corners. 2' minimum depth into undisturbed soil. The depth should equal or exceed the height of the pier. The soil consistency seems to depend if you're east or west of I-35. Lot more rock west.
You can put the posts on top of the subfloor. 4X4 treated is fine for post since its just holding up the roof, not ice and snow. Consider hurricane straps on all the posts, top and bottom. Rafters too.
I'd use 2X10 treated lumber for headers/beams. Consider treated plywood between. Use 1/4" galvanized bolts/nuts/washers to make the beams.
Consider a skirt of some sort around the subfloor framing. Cheapest is plastic latticework.
Think you mean 13' each side, not 13' square.
--
Dave

Apathy and denial are close cousins
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