How to cut a large hole in a concrete wall.?

Question

I need to cut a 3 foot circular hole or 3x3 square hole (which ever is easier) in a 2 foot thick concrete wall for a vent.

I have no idea how to proceed, any literature or suggestions?

Answer 1

1.5 lbs of dynamite =D

Answer 2

First drill through the corners to mark them. This needs some careful measurments as you'll need to drill from both sides with a 12 inch impact masonry  bit.

Then drill at least 3 or 4 holes along each line for guides.

Use a skill saw with masonry blades to make the initial cuts (from both sides) and then chip out the center. Small electric impact chisels can be rented.

With good tools it shouldn't take but a few hours to get through. Be prepared to cut through any rebar you find with good sharp metal bits. Rebar is very soft.

Answer 3

u could use a dimond drill,but would be expensive to hire with the size of hole u need. y u need a hole that large i do not no? other than that u need a hand held breaker with chizzle bits, and u may need to put a lintel in with the size of the hole.