Did I miss anything?
That 2nd pic looks like an attic “moisture management” problem, such as poor ventilation and/or insulation, bath fans vented into attic, etc., and not the result of uncaulked/sealed nail heads. JMO
It is certainly possible that condensation has been forming on the nails because of a bath fan or other ventilation problem.
They also expand and contract, which enlarges the hole in both the roof-covering material and sheathing, providing an avenue for moisture intrusion.
The nail will from frost on them. One should always use galvanized hot dipped or stainless ringed fasteners. If the roof is well insulated and has sufficient ventilation, yes I here you un-vented, vaulted, cathedral, or closed closed roof deck guys out there,then the likelihood of moisture on the metal in the unconditioned vented attic space will be reduced.
You see rust on the nails.
did you ask the vendor how old the roof was. Get any warranty from the vendor if the said the roof was x years old?
Did the agent offer you any receipts pertaining repair, maintenance, warranty?
Up and down expanding and contracting.
Now when you look at the deck from the attic space, look at the nail pattern.
Tell me what you see Juan.
Juan does the nail actually shrink as it rusts as I think of lintels which expand and crack mortar ?
I think you got a reply to you blog.