Sure, it's not rocket science. The main thing to be careful of is to change
the angle slightly every so often as you drill. Drill straight in, and the bit
will get stuck. You want to keep moving the bit around a little as you drill
so that you make a hole that's maybe 1/8" larger than the bit, on all sides,
all the way down.
And wear ear and eye protection.
Doug Miller (alphageek at milmac dot com)
I agree that an electric jackhammer is the way to go. You're going to be
there two forevers doing it with a hammer and chisel. About the biggest
hint I can give you on the hammer is get the pointy bit, and always aim
towards the center of the blob. Start slow until you get a starter hole,
then you can apply more pressure or higher impact rate. Any way you cut it,
you have a job ahead of you. I had to jack out a block wall footer, and it
was a nightmare with the rebar and no cutting torch.
I had a problem like that once. I ended up digging a very large hole
and rolling it in then covering it up. I would really like to be there
someday when someone digs up that cube (4' x 4' x 4') and wonders why it was
For really thick concrete, I once used an electric jack hammer and the best
I could do was break off pieces from the edges and corners. That left me
with a ball of concrete and I finally did what someone else suggested -- I
dig a whole next to the concrete, rolled it in, and buried it.
But, in another case where the concrete pieces were thick (about 12 inches),
and not wanting to rent a jack hammer, I used a big crowbar to lift one end,
then placed a rock or whatever under the concrete, then hit it with a sledge
hammer to break it apart. While sitting on the ground, I could never break
it. But when propped up on a rock or whatever, it is much easier to break
pieces off. I also use a garden hose to rinse off what I am working on and
I can easily since where it is cracking from being hit with the sledge
hammer. And, finally, with the big crowbar, if you can find any kind of
crevice to work the crowbar into, you can break some pieces apart that
way -- more science and leverage and less brute strength and muscle power.
I've broken up 18" round piers with an electric hammer, the cheap Harbor
Freight one, and
did it with stitching (hammering a spot for 6 or 8 seconds and then
repeating a few inches over). When
you get a straight line of the divots all the way across, at some point the
concrete breaks along the line.
You can actually get a pretty straight cut with this method.
The common denominator is power tools: jackhammer, 14" or 16" portable gas
saws, concrete chain saw, etc.
If you are not able to break it with a hammer after lifting a corner up like
other suggested, try drilling holes and insert special steel wedges and tap
away, something like this:
Drilling holes without a rotary hammer would be a challenge but you have the
The easier way is to drill holes with a rented rotary hammer and fill them
with an expanding agent like www.crackamite.com I used something similar on
a slab a few yrs ago and it worked great. you can Google for other
varieties, should be available @ a local industrial supply outfit.
Go down to the local Gym. Find about 20 very muscular gay men that
lift weights. Invite them to your place and let them bang each other
on the concrete. You'll end up with a pile of sand. It should be
easy to find these guys in SanFrancisco.
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.