Aligning opening in exterior wall
Am am preparing to cut a rectangular opening (3.25" by 10") in an exterior wall to vent a range hood.
After transferring the cutout template onto the inside drywall I think the next step would be to drill (using an 8" or longer wood drill) a hole in each of the four corners that reaches through the wall and through the sheathing. The problem I see is getting the drill to pass through the 4" wall space to the exterior sheathing and be aligned with in a perpendicular (horizontal, as well as horizontal yaw) path. My drill has a level on it, but that is only one of the two directions that have to be perpendicular. I may try to make use of my hand-drill drill stand to see if I can place it against the wall to guide the drilling operation.
I think I can also make the opening in the sheathing about 1/4" bigger on all sides to compensate for errors in alignment. The vent housing has a flashing/sheild about 2" wide to cover the opening in the sheathing.