JayJ, I have to say that you have me confused. Just because something conducts electricity does not mean that it attracts it. We have Aluminum siding on the gable ends above brick. Why would that have to be grounded. I think that it would be more dangerous if it was. You have to have electricity flowing for it to do anything. No ground, no movement. I remember that when we were in Tulsa, I had an old and tired electric drill. When I would use it with rubber soled shoes and on a hardwood floor, I might get a slight tingle every so often. Then, one day I used it while I was standing barefoot on a floor furnace. I saw and felt sparks like crazy. It hit me so hard that I had to almost will my finger off the trigger. I tried it again with tennis shoes and the hardwood floor and got just a little tingle. The pipes and such from the furnace were a perfect ground. No ground, no electrons moving, no jolt.
Certainly, the rain on the side of a house would make a path to ground, but this would be the case with wood, brick or asbestos shingles, and those aren't grounded. I'm not trying to start a big battle (but it probably will anyway, LOL), but I just don't understand your reasoning. Can you explain? Thanks.
Another example, lightening hits a tree that is grounded and has sap in it. It gets fried. Lightening hits, or a power line falls on a car with rubber tires and little to nothing happens to the occupants. The rubber is an electric resistor and what electricity does move stays on the outside skin.