For those of you wondering how to stick a 12 to 13ft long pvc pipe through a six inch hole under a roof, you have to cut a square hole in your decking between the josts and angle the pipe in and bring back up flush into 6in hole from the underside.

You'll need to add 2x6s to each side of the bigger hole and 2x4s behind the deck boards you removed and are now replacing. Works kind of like a man-hole. We later enlarged to 3ftx3ft. Had drop new 4x4 posts and case in with 2x6s. Some in the water bracing. Worked out nice.