I need some guidance on how to securely install a ceiling fan on my aluminum structure patio cover with an acrylic roof. I have a double-walled beam (attached image for reference) where I would like to mount the fan. However, there is a C-shaped fold on the edge of the beam, which makes it challenging to use bolts and nuts for installation.
My initial idea was to attach a fan box to the beam using self-tapping screws. However, I am concerned about the fan's torque potentially causing the screws to loosen over time, leading to the fan falling.
I would greatly appreciate any advice or suggestions on how to properly and securely mount the ceiling fan to the beam in this specific situation. Are there any alternative methods or specialized hardware I should consider to ensure the fan remains stable?