How do you knock out a "knock out" on a Catch Basin?

Question

How do you create the hole for a pipe on a "knock out" on a Catch Basin?

Answer 1

go to a concrete supply company and try to either buy or rent a concrete asphalt cookie cutter.

Answer 2

can you take a digital picture and post it? If i can see what you are trying to do i can give you a solution

Answer 3

take a sledge hammer and hit it it should knock it out

Answer 4

Usually, they have a section that is thinner for the knock-out. Simply use a sledge hammer to break out the opening. This will probably be much larger then the pipe you want to put in. You will need to clean the edges, form around the pipe and pour in grout to seal back up. Could also try using a core saw to cut the hole for the pipe, then you can pack the grout in by hand to seal opening.