It's coming to the time where I'm planning on ruining my lovely brickwork by coring holes for ASHP flow/return.  I'm at the point where I'm trying to figure out how to make it look presentable and finished...   Because I'm using 22mm+19mm walled insulation, I have a 65mm core drill for individual holes if I choose, but I've also seen pictures of installs where a 120mm hole has been cored and both insulated pipes shoved through, looks a dogs dinner though.   I've got various s