In an attempt to run Cat6 Ethernet cables to my living room, I cut a handy box sized hole in the the block, but was unable to run the cable down from the attic at the top of the wall (it was obstructed about 3 feet up or mid way on the wall). In the end we put the connections in the ceiling. Now there is a 1.5x2.5 hole in the interior side of one concrete block.
- My thought was to fill it using expanding foam and drywall mud.
- What is the best way to fill it properly?