I am contemplating doing a self install of a direct vent gas stove due to the mind boggling installation cost. It has a 7-inch vent pipe and I want to run the pipe (per the manufacturer's instructions) directly through the outside wall to a terminal box. The wall on the outside is brick, one layer of bricks thick. How on earth do you make a 7-inch hole for the pipe? I have heard of core drills, but they seem to only go up to 6-inches.

Ideas?

Thanks.