Cutting Out Built In Shelves
I take it you are talking about a flat screen tv over the fireplace. Check your warranty for the tv, I believe you're going to find it will be voided for this type of installation since the heat from the fireplace affects the electronics. I know, I know you see it done everywhere ...... plus its bad on your neck trying to look up
if you must ...... make sure you put a deep mantel over the fireplace in an attempt to direct the heat away from your tv.
my humble thoughts .....
"You get what you pay for, and sometimes free costs more!"