Breaking up concrete

Dave Martindale · 2008-04-04T18:26:27+00:00

Our house has a flower bed immediately in front of the foundation.There's a patch in the flower bed that has no significant plants growingin it, and we decided to add some. When we tried to dig a hole to plantthem, we discovered why there aren't any plants there:It seems that someone had some leftover concrete, perhaps from pouring astairway nearby that goes from driveway level up to front lawn level,and they simply dumped the excess concrete into the area that wouldeventually be the flower bed. There is a chunk of concrete about 6inches thick, 6 feet long, and 2.5 feet wide in there, with a few inchesof dirt over it. The concrete is not attached to the foundation or thesidewalk, it's just lying there. But it's too heavy to move as a singlepiece.So I've been breaking it up into smaller pieces, using a single-pointconcrete chisel and a 3 pound club hammer. This just doesn't work verywell for breaking 6 inch thick concrete. I end up holding the chisel inone hand and the hammer in the other until I get the chisel embedded farenough to stand up on its own, then I switch to two hands on the hammer.Sometimes this works in a half-dozen strikes, sometimes it never worksand I try moving the chisel somewhere else. I've probably spent acouple of hours on this already, and it's down to half the originalsize, but progress is discouragingly slow.The two ways to improve the situation seem to be: get a bigger hammer(e.g. a long-handled sledgehammer), or some sort of power hammer. Whatwould be suitable for 6 inch concrete? Dave

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Dave Martindale 18 years ago

Though I didn't mention it, I'm already doing this. Using a heavy shovel and a digging fork, I've been prying up one end of the concrete and putting a rock underneath it, a few inches back from the end, so that the concrete is unsupported at the end and stresses in the concrete are concentrated around the rock. Without that, I would have gotten nowhere with the hammer and chisel.

It seems the most common recommendation is to just get a bigger hammer and hit the concrete with it directly, forgetting about the chisel. So I think I'll try that.

Thanks for all the suggestions!

Dave

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Dave Martindale 18 years ago

That would be efficient alright, particularly if I happened to have either the backhoe or the dump truck.

However, the concrete is in a restricted space that would make this tricky. The concrete I want to get rid of is in a flower bed that is located between the house foundation and the front sidewalk, and it needs to come out without damaging either the foundation or sidewalk. In addition, the house overhangs the flower bed by a few feet so there's no clear vertical space above the junk concrete. It might be difficult to get a backhoe bucket in there without touching the house.

Maybe a little Bobcat-sized backhoe would be OK, though I don't happen to have one of those either.

Dave

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Rich 18 years ago

Call the police and tell them John Wayne Gacy rented the house years ago and your smelling something foul coming through the concrete. You'll have a crew there in no time.

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Dan Espen 18 years ago

Yeah, now you tell me.

Actually, I did a large patio and didn't pay much attention to how I held the hammer. I had bruises all over my legs but didn't notice much pain. Must have been too tired to care.

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HeyBub 18 years ago

Do you have a (really) long chain and a bumper?

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Oren 18 years ago

I call that Silent Contempt.

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Dave Martindale 18 years ago

"Get a bigger hammer" turned out to be an excellent suggestion. I bought an 8 pound sledgehammer today. It took two blows to break the remaining concrete in half. Three more blows and it was in 5 pieces, all small enough to pick up easily. I was done in 5 minutes.

I sure wish I'd bought the larger hammer at the beginning of the project!

Dave

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aemeijers 18 years ago

So now, grasshopper, you understand why the term 'BFH' is used so often in this group. Don't need it often, but when you do, there really is no substitute.

-- aem sends...

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Stormin Mormon 18 years ago

Oops! I'll try to do better.

Oh, be sure to use two hands holding a Sawzall, so you don't cut the index finger off your left hand. You'll need to know that in about two years. I didn't want to be late again.

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Stormin Mormon 18 years ago

Usually meant in jest. But this time, it was the real advice.

Thanks for letting us know how it worked out.

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Stormin Mormon 18 years ago

The other essential time is removing wheel studs from your car or truck. The one time I couldn't get a wheel lug off, and drilled a bunch of metal off it to get it loose. Damaged the threads. I bought a replacement stud. Tried heat and a big C-clamp to get it out. No such luck. The BFH came out, and that popped the stud loose.

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