I doubt it will work. Use a steel pole or one of those mounting poles that Davis offers or similar. Fiber glass will snap. Wouldn't worry about lightening hitting your pole. Why are you mounting the unit on the roof in the first place, I can see putting up the wind portion of the unit there, but not the rest. radiation off the roof will screw with your temp/humidity. And you will have to climb up there to clean out your rain bucket of debris , unless you like doing that stuff. If you want to ground it, run a copper wired that is attached to the pole, to a grounding stake in the ground.