brick
I currently have a small hole in my brick wall that is bringing a cable for my satellite dish into my house.
I now want to install outdoor speakers in my backyard and I would like to feed the speaker wire through this hole, however it is too small.
I'd like to make the hole a bit larger without having to do any drilling to avoid damaging the existing cable. Is there a way to chip at the hole to make it larger that won't risk splitting the brick?
"Is there a good and code-compliant way -- and barring that, just a good way -- to rectify this situation WITHOUT REMOVING THE BRICK OR INTERNAL STRUCTURE?"
No.
"I am planning to remove all of the sheetrock and insulation in the affected rooms, cut the brick ties (most of which are rusted anyway) after supporting the fascia from the exterior, slip housewrap between the studs and the fascia, and then slip a sheet of 4x8 1/2" (or less, I think I saw 1/4") of extruded foam sheathing between the studs and the housewrap. The entire thing will be re-anchored and affixed from the outside using CTP Grip Ties or a similar product. This should provide a watertight, sheathed, and even (insufficiently) thermally broken envelope without having to do any tearout work beyond the sheetrock."
Your plan sounds like it could work, (except for the challenge of slipping 4x8 sheets of anything between studs and your bricks).
As a suggestion, I would use diagonal metal strapping for lateral brace across the studs if you are not using structural sheathing (i.e. foam).
See this article (goto page 2) and below image from finehomebuilding.
You can patch it with hydraulic cement similar to this type
You need to carefully remove all loose material and clean the area. The cement is fast setting and expands slightly as it sets, making a tight seal. Only mix as much as you can use in a few minutes.
Best Answer
Technically you could use some device for precision grinding like Dremel with some diamond bit with an extender to make it long enough, but that's almost mission impossible to do. First, you risk damaging the existing cable. Second, doing such job in a hard material when the hole is long and narrow will take too much time and precision to be worth it.
You actually have two options. Option one is to drill another hole or maybe find some other way to lay the new cable. Option two is to disconnect the cable, remove it, drill a wider hole in place of the existing one, then install the old cable and the new one.