Installing aluminum trim over wood fascia

[homeowner123]

About 12 feet of aluminum trim covering the fascia on my roof just blew off in the wind, and as I looked at it the two pieces there was only one nail for about every 6 feet. I understand that wood expands due to moisture and aluminum expands with temperature, and lots of nails might cause bumps in the trim, but it seems to me that more nails would help keep the trim on more securely. Are there any standards in the industry for installing alum trim over wood fascia? Such as how many nails per foot and placement of the nails? Also, none of the overhang was screwed into the soffit, and I've heard that this is a good idea. Is that true? About half of the soffit is hanging out under the trim overhang and it looks pretty bad. I can shove it back in, but it pops out again later. Should I go back to the contractor and ask them to re-do their work?

[HayZee518]

what the roofing contractor does is he makes a folded over track that the upper part of the fascia strip gets shoved into and he uses white nails or colored nails to hold this strip in place. this formed on his "portable press brake"