Replies

1. Expert Member
   Akos | Apr 11, 2021 09:33pm | #1

   A hefty SDS plus hammer drill with a 6" core bit. Drill out from the inside with a 1/2" bit to mark the location on the wall outside. Drill from the outside to avoid breaking the bricks when the bit busts through. Once you are through the first wythe you can drill the rest from the inside if you want to. Much quicker than drilling around the circumference for a large hole like that.

   Two important rules I have when drilling big holes like that, never have the drill near your body and never grip the handle with your thumb. This way when the bit gets stuck, it won't rip your arm off or hit you in the head.

   You can also go for a 3.25x10 vent hood, there you just chip out the bricks that are in the way. Usually much quicker.

1. 
   DominicL | Apr 20, 2021 09:41pm | #3

   Thanks a lot Akos ! Very good tip with the 3.25 x 10 ! I’ll dive into that option if compatible with my new range hood which is 6” round at the outlet. If not, the core drill seems good.

   Regards, Dominic

2. Expert Member
   BILL WICHERS | Apr 12, 2021 12:29am | #2

   If you use a core bit with a center drill, you can drill in from the outside a bit, then use a small diameter bit to make a pilot hole all the way through (I have a 24" long 3/8" bit for things like this). This way you can line up the core bit on either side of the wall and have the holes "connect" perfectly. You want to drill in at least maybe an inch or so on the "far" side to avoid major blow out of the wall. I like to say that hammer drills make "entrance" wounds and "exit" wounds. The exit wounds can be BIG -- I've sometimes had entire bricks work loose or halves of concrete blocks blow out.

   I use my big rotary hammer a little differently than Akos here -- I usually brace it between my arm and body so that the side of the machine is against me. You have to be careful and ready to let off the trigger if it starts to bind. The worst thing you can do is have the drill supported by just a finger or two in way that it can swing around and break your finger, or hold the drill out in such a way it can spin around and smack into you. It will hurt you with impact or force on something small like a finger, but pressure over a large area isn't usually a problem.

   BTW, if you don't want to tackle this hole, there are contractors that specialize in just drilling holes, known as "coring" in the trades. On big commerical buildings, it's common for the GC to contract with a coring company that then drills all the big holes for all the other trades. It will be a few hundred bucks to have them come drill your hole, but that might be worth it to you.

   Bill

1. 
   DominicL | Apr 20, 2021 09:44pm | #4

   Thank you Bill for your guidance, it’s appreciated and I’ll be sure to drill a hole trough and to core the first wythe out from the outside to prevent a “bust”. Have a good one ! Dominic