I agree, I recently installed a ceiling fan in place of an old boring ceiling light. All I had to do was replace the junction box with a weight rated junction box that held between the two ceiling joists.
Welcome Kdurden, to the best darn DIY'r site on the web.
This new deck, is there a wall mounted fixture on the outside of the house close-by? If so why not tie into that box and run EMT to the fan mount box. Yes the light switch would have to be turned on but at least you would have your power when you wanted it.
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