Removing just the end of a concrete/cinder block wall

[dave11]

I'm planning to remove just the end of a concrete ("cinder") block wall in my basement. The wall is about twenty feet long, and at one end is a steel I-beam supporting the floor joists, and at the other end of the wall, the blocks do not reach the ceiling, and are there just to form a partition. It's the partition end that I want to remove. About one and a half blocks, or 24 inches.

The mortar gives way to my rotary hammer (with chisel bit), and the first few blocks have come off easily, though the mortar of the surrounding blocks seems to loosen a bit as well, from the movement of block i'm working on. This would be fine if I were removing the whole wall, but obviously, most of it needs to stay. So I need to be careful.

Eventually, I will need to cut a block in half, on every other course, to even out the end of the wall. My question is whether I should just cut the respective block in half while in place, using a masonry blade, or whether I should remove those blocks entirely, and replace with a pre-cast half-block. That would make the edge look neater. But might breaking those original blocks loose weaken the surrounding blocks (which I need to keep)?

Appreciate any input.

 

[DAKSY]

You might be better off placing the end of a short section of 2x4 against the block you want to remove
And hitting it with a BFH. This will tend to localize the shock to the block you wanna remove instead
of loosening all of the surrounding blocks like the hammer drill. I've used this method with some
success, maybe it'll work for you. It's worth a try...

 

[Hogwildz]

Cut saw with diamond blade is what I would use.
Id ya can cut to the outside of the center web of the block. it will keep the strength of the block on the cut side and leave you a fairly straight edge if cut straight.
The just knock the ones you want out. The ones that are already loos will have to be replaced, or cleaned and re-mortared.

 

[dave11]

Cut saw with diamond blade is what I would use.
Id ya can cut to the outside of the center web of the block. it will keep the strength of the block on the cut side and leave you a fairly straight edge if cut straight.
The just knock the ones you want out. The ones that are already loos will have to be replaced, or cleaned and re-mortared.

Another problem is that the blocks have two webs, and so are divided in thirds, so cutting through them in the middle will leave a concave space. This was one of the reasons I was thinking about removing the end blocks instead of cutting them, and replacing with cast end-blocks.

 

[Gooserider]

Not an expert, but as I see it, the problem is that you would have a really hard time removing the alternate blocks to replace them with half blocks without loosening the adjacent blocks and then getting those back without loosening the ones next to them, and so on... It's sort of like a hole in a knit sweater - once it gets started it is hard to stop the adjacent stitches from letting go...

As I understand it there are essentially two options,

1. Remove all the blocks from where you want to stop on a diagonal to the top of the wall, and then build it back up to your stopping point substituting partial blocks as needed

2. Make a cut in the wall at your desired stopping point, or possibly a bit past it, and then after removing everything up to the cut, make a form and pour a cement filler column to give a smooth end on the wall, or possibly just box it in with wood or other material to hide the jagged end.

Gooserider