The highest the ceilings go in my house is 7 ft 6inches or so… (can’t remember exactly but it’s pretty pathetic!). I have two pole rooms and one of them has a 6ft 9inch ceiling. I pole in this room all the time, although I do admit the lack of height is an annoyance at times. Most moves are no problem with a low ceiling, and I usually just go to the studio to practice the moves that do require height. It’s doable, and you’ll learn to work with what you’ve got. 🙂
There are quite a few polers on here with low ceilings. If you’re concerned you won’t be able to pole beautifully, please check out a dancer on here named Papillon – she’s absolutely incredible and she also poles with very low ceilings. Somehow she manages to make a climb on a low pole look so graceful and lengthy! I still haven’t figured out this secret yet! 😀 Plus, Veena gives tips in the lessons on how to climb, etc… on lower poles.
As for finding a joist – I had a hell of a time finding the joist in my ceilings even with a stud finder. I found a hole the previous owners of the house had cut into the basement ceiling and measured the space between them. Starting from the wall I measured outwards until I found the joist in the center of the room. Most houses have joists set a standard distance apart. You might be able to do something similar to locate the joist in the taller part of your ceiling.