If your cut doesn t need to be exact use a cold chisel and hand sledge to cut the concrete.
How to cut a doorway in a concrete block wall.
Cutting the foundation wall.
Don t force a blade into a cut.
A circular saw with a masonry blade can also be used to either score or completely cut through the block.
This lumber should be within 1 8 inch of what the width of the concrete block wall is now when you add the thickness of.
Cut through the remaining lines until you have created the opening.
A huge water cooled cutting saw attaches to each rail and is slowly moved up and down the rails.
Removing all the blocks taking outside cutting and re fitting the halves i guess it ll all be tidied up afterwards with plaster etc.
Choose which side you will start with and punch a hole in the other side with a sledgehammer which will help draw concrete dust away from you as you cut through the wall.
Use a sledge hammer to break through the concrete inside the scribed lines.
Knock the first one out in the centre then use a multipurpose handsaw to cut the mortar and remove the blocks.
When you get near the edges of the opening you may wish to switch to a masonry chisel and hammer to prevent accidental damage to the surrounding walls.
Step 4 re form the blocks as needed.
In the photo above the right side of the right vertical rail has been cut.
Score the length of the cut three or four times with the chisel.
Each time the saw makes a full pass up and down the contractor increases the depth of the saw blade so that it eventually cuts through a 10 concrete wall.