Where power enters the house: the weatherhead, the mast, and the attic feed
People picture the electrical panel as the front door for power. On most homes with overhead service, the real front door is up at the roofline, and understanding what happens there explains a lot of what a meter finds one floor below.
The path, in order
Follow the wire from the street. The utility drop crosses from the pole to a bracket near the top of the house. It connects to your conductors at the weatherhead, the weatherproof fitting at the top of the mast. From there the conductors run down the mast, into the meter, and only then into the panel. By the time power reaches the panel it has already traveled the full height of the house as the single largest current path it will ever be. That path is why the power lines page spends so much time on the service drop: the field around a conductor depends on the current it carries, and nothing in the house carries more than the service entrance.
Why the roofline location matters
The mast and weatherhead are outdoors, above the living space, which is good news for the rooms below because distance does most of the work. A service entrance six feet above an unoccupied attic is not a bedroom problem. It becomes worth a look only in specific cases: a finished attic room directly beside the mast, a panel mounted on the far side of a bedroom wall, or feeders that leave the meter and run horizontally through the attic above rooms where people spend hours. In those cases the same reasoning from the net currents page applies, and a gaussmeter settles it quickly.
What can go wrong up there
The service entrance is mostly a water and mechanical story, and the electrical field question rides along with it. A mast that has worked loose, flashing that has failed, or a weatherhead that has cracked are all first a leak and a safety issue, and the fix belongs to the utility and a licensed electrician, not a homeowner. The field angle is simpler than people fear: a properly run service entrance produces a strong but tightly local field that falls off fast with distance, exactly as it should. The readings that deserve attention are not at the mast itself but where a feeder has been extended, spliced, or shares a path it should not, which are the wiring errors this site keeps returning to.
The one time you can see it
The attic and the roofline are sealed to normal life. The moment they open, during roof work, attic finishing, or an electrical service upgrade, is the moment to confirm the entrance is sound and to note anything running above the rooms below. That is the theme of the companion article on what a re-roof uncovers: not to turn a roof job into an electrical project, but to use rare access well while it is free.
The calm version of the story
The top of the house sounds dramatic because it carries the most current, but the physics is reassuring. Height and distance are on your side, a correctly built service entrance behaves itself, and the meter tells you in five minutes whether any of it reaches a room you use. The value is in knowing where to look and when the looking is cheap, which for the roofline means the few days it is open.