I have a 3X3 window in my cinderblock basement. The blocks are the 12 in wide blocks.
I would like to take out the makeshift window that was installed improproperly and put block back in.
Do I basically mortor in the new cinderblocks, or do I need to cut into some of the old block the insert part of the new block to get that zig zag affect. I will be putting drywall up in the basement and will be stuccoing the outside of the house.I worried that the perimator of the patch block my crack and show when the freeze and thaw comes.
The other questionis In order to match up the cinderblock mortor lines I will need to put bricks on the bottom row first ,because theexisting lower cindder bolcks were cut into. Would this be the proper way to line up the blocks mortor lines.
Thank You
Rob

My opinion. Cut out full blocks, but you don't have to have a zig-zag pattern. Putting in that last course of bricks might be difficult.

You could use a cement blade and a rotary hammer to remove the blocks.

Make sure you use muratic acid on all the surfaces before you stucco and make sure the new concrete gets a chance to cure properly.