Jon Danniken wrote:
Bob F wrote:

If you have the working space, a long flex drill could get you
through the firestop, or a shorter one might be angledfrom the box
hole to the outside of the wall and back to the inside wall at the
bottom so as to angle through the bottom footer.

Interesting, I hadn't thought of going through to the outside. Thanks.

To avoid confusion, I wasn't saying to go through the outside, but to flex the
shaft of the drill from the box hole, out against the outside and back to the
inside in an arc so that it angles back towards the inside where it drills
through the bottom plate right against the insode wall. You would need a helper
tool of some sort to get the flex right probably.