Having had to remove a lot of concrete from an in-ground pool that had
been filled in when I dug my pond, I have a lot of experience in this.
I found six inches almost impossible to break with a 12# sledge
hammer, even if it was not on solid ground. If you are removing a
section between two expansion joints you won't need the diamond saw.
If your not ending at the expansion joints, I would recommend you rent
the gas powered diamond saw and make a cut at each end of the area to
be removed. Be prepared to get ripped on the blade. I don't know
where you live, but if you anywhere near Cleveland, OH I'll let you
borrow the one I have. You will not be able to cut all of the way
through. With a 14" blade, I think you will be able to cut about 3.5"
deep. The idea is to get a good clean edge for appearances. It is
also a good idea to slightly bevel the top edge of the part to be left
to prevent chipping. The second tool you will need is a 65# electric
jack hammer. You should get two bits. One is a chisel style and the
other is pointed. I found the chisel style worked best for me. Make
sure you have a 12 ga extension cord for it. Place the bit about 4"
from the edge of the sidewalk and go at it. Do not try to take to
much at a time as you will just end up with the bit stuck it the
middle of the concrete. This is why you want to make sure you get two
bits. Don't ask how I know. If the concrete is reinforced with wire
mesh, a pair of bolt cutters and a pry bar are very helpful. Cut
through the walk like you were chopping a log in half. Once you get
through the width of the walk, you will find it easier and be able to
break off bigger hunks, 12" - 16". When doing the larger pieces,
don't try to go all of the way through. The idea is to weaken it in
an area and then move over some along a line. It does help to
undermine the concrete, but is not necessary. If you lucky enough to
be removing a section between expansion joints, I would recommend
prying up one end if possible as it will make it easier. Just watch
the hands and toes. BTW, it is very heavy work using the jack hammer.

If you have back or heart problems, get someone else to do it for you.
I have found high school football players like doing this sort of
thing.

(Eric Hanson) wrote in message om...
Hello,

I am planning on extending my pond in the coming weeks. The current
pond is about 22' x 7'. I want to dig an extension to make it an
L-shaped pond. The problem that I am having is that I would have to
"dig" through a 6" thick concrete walkway. And I have no idea how to
remove it safely and with a low cost. I quickly tried to pound it with
a sledgehammer, but it did little to the concrete. Not even a crack. I
quickly stopped because I was worried about the fish and vibrations.

Does anyone have any suggestions/comments?

Please see my site for images to get a better understanding of what I
am trying to do. I look forward to ANY responses. Thanks for your time

http://www.pobox.com/~ehanson/aquaria_pond.html