Disclaimer: X-Pole will always be your best source of installation information. Any physical installation in a rental residence may create a liability against your deposit or move out expenses. The below is also a suggestion with many variables, professional installation is the only way to guarantee your safety.

With the above out of the way my recommendation would be to cut a square piece of plywood that would span two joists entirely. In the US most joists are 16 inches on center which means to fully span two 2×4 joists you would need an 18×18 square of plywood that is minimally 3/4 inch.

Firmly attach this piece of plywood on either side to parallel joists, then bolt the mount to the center of this.

Since a permanent mount like these requires less pressure from the pole it should be more than adequate as a mounting spot for your pole.

NOTE: it doesn’t take nearly as much pressure from the pole when you have a permanent mount since you only need enough pressure to keep the pole on the ground since the top pressure plate is no longer used. This means you can get a better spin and will experience less long term bowing of your pole.