how to upgrade an older home electrical
Ditto, what oh'mike said. FYI, "electrical service" usually refers to some combination of, the weatherhead, meter can, and, first and/or largest panel. Get detailed estimates to know how each electrician defines that term. Replacing all the rest of the wiring is a whole house rewire.
A whole house rewire is probably unnecessary. Additional circuits may be advisable. Existing conduit is safe above the rafters and grandfathered in.
Conduit resists physical damage much better than romex, and it lasts forever, except for rust. To rust out conduit requires chronic and severe water damage, seldom found in attics. Loose conduit joints can compromise your ground. And if you have wobbly boxes, you may have hidden, loose joints. The easy fix is to include a bare wire with any replacement pull.
Rafters are load bearing. There are building codes that specify the size and location of holes. For safety, know before you drill.
Expansive hydraulic cement might be the answer to loose boxes in cinder block. It expands to wedge the boxes in tight. Regular cement shrinks. Fill a plastic bag and cut off a small piece of the corner. Use it like a pastry chef. Fill between box and block.
Last edited by Glennsparky; 10-08-2012 at 07:46 AM.