It must be remembered you must have great soffit ventilation so the air travels through your attic as a constant breeze.
How to cover those nails sticking into the attic.
If you have a friend in the attic ask him to direct you to a sturdy spot where the nail can bite into the wood.
Fill small nail holes with silicone caulk or roof cement.
Smaller nail holes will be permanently fixed by this method standard roofing nails would be either 3 8 inch or 1 2 inch making a hole.
One possible solution would be to increase the thickness of the soffit with extra wood or vinyl materials as in essence a nail base.
Unless you live in your attic the protruding nail heads shouldn t be a problem.
Your roofer should be willing to work with you to address the cosmetic concerns to your satisfaction.
If you are using an approved roof sheathing that is less than 3 4 like 7 16 osb or 3 8 plywood then the nail must go all the way through.
If you use your attic for storage and need protection buy an insulating foam and have it sprayed against the walls.
Silicone or acrylic latex caulk caulk gun for sealing small holes 1 4 inch or less several cans of expanding spray foam insulation for filling larger gaps 1 4 inch to 3 inches special high temperature heat resistant caulk to seal around flues and chimneys.
A point often overlooked is old houses didn t have this frost on nails problem.
Without delay this air movement brings in drier outdoor air into the attic.
Cut the tubing into pieces about 3 8 to 1 2 long depending on length of exposed nails in your attic then push a piece of tubing onto each nail point.
No more nails in the head.
The dry air evaporates the frost.
If you are using roof sheathing that is 3 4 or thicker then the nail must penetrate 3 4 min.