View Full Version : Jack Hammer: Anyone used to break up concrete


ron in sc
04-19-2007, 01:34 PM
I'm thinking about renting an electric jack hammer to break up a concrete walkway, concrete is 30 years old and 3 1/2" thick.

What bits are best, point, flat, whatever? And how tough is it to break up 3 1/2" concrete?

iiibdsiil
04-19-2007, 02:18 PM
If you have got a good back, or good help, you could consider renting a concrete saw. Cut it out in sections, lift, and remove.

PAToyota
04-19-2007, 03:45 PM
I was surprised at how easy it was to break up a sidewalk with a sledge hammer and digging iron - pry a section up a bit with the digging iron, hit it with the hammer, hit again for smaller pieces.

bmwpower
04-19-2007, 04:02 PM
3-1/2" should be no problem. Just let the hammer do all the work. It's loud and a mess, but it works. Probably the pointed bit should be best all around bit.

Junkman
04-19-2007, 04:07 PM
I have no use for Jack Hammer, because he came between me and my old girlfriend. :mad:

bmwpower
04-19-2007, 04:09 PM
I have no use for Jack Hammer, because he came between me and my old girlfriend. :mad:

Mr. Play On Words at it again.

So that's what happened to the old lady?

ba614
04-19-2007, 04:09 PM
I'd use the flat chesil {sp} type bit ... if yer young and strong a 10# sledge'll do a number on that driveway ... the thing to remember when using a jackhammer is to let it do the work ... you don't have to hold on to it real tight and pushing it hard will only wear you out ... let that thing jump and bounce and it'll do the work ... the only reason you hold it is to point it in the direction you want it to work

Junkman
04-19-2007, 04:11 PM
Mr. Play On Words at it again.

So that's what happened to the old lady?

Haven't seen her in a long time. She had a lot of miles on her, and I believe that she retired after a Goodyear.....:lol_hitti

66RICH
04-19-2007, 05:00 PM
The electric hammers are pretty good, depending
on how much you have to do. The pointed chisel
worked best for us, that and long pry bars.
I had 60' to do, and used an air hammer my friend
had. I hooked it directly to my comp with a 3/4"
hose, worked great. My son, and 3 of his friends did
this in one day, worked thier butt's off! The city
hauled everything away for nothing.
Total cost= lot's of pizza,pop, and beer afterwards!

Rich

1320stang
04-19-2007, 06:29 PM
I've not used an electric one, I've used a 90# air hammer though. Had to go thru 8'-10' of solid concrete, took a week or so, it's sorta foggy in my memory, something I've tried to forget, I just remember it sucked. I also had to help dig about 120' of trench 4' wide and 4' deep on that job by hand. That's sorta foggy as well.

The pointed bit always worked best for me. Do a series of holes and use a sledge to connect them. Then use a pry bar to seperate them. Make them as big as your willing to move.

RPH
04-19-2007, 09:43 PM
Try to pry a section up in the air with a bar and whack it good with heavy sledge hammer. Concrete does not like this type of load. Once a piece is broken use the smaller chunks to hold the larger ones up once you pry them up. did this in high school for summer work with a contractor, works great.

TNToy
04-19-2007, 11:15 PM
Try to pry a section up in the air with a bar and whack it good with heavy sledge hammer. Concrete does not like this type of load.
Exactly. Concrete is terrific at resisting compression loads. Torsion and tension are it's weaknesses.

Electric jackhammers are pretty pathetic, but for concrete that thin, might be OK. As stated, a sledge and a couple of LONG bars will get you almost as far, as fast. Keep them on hand as a backup. ;)

wilbilt
04-19-2007, 11:39 PM
I have used a few rented electric jackhammers (Bosch).
To break up concrete, the point seems to work the best. For skimming the old mortar bed from a tiled commercial bathroom, a flat chisel works well.

By all means wear hearing protection. These things are loud if working in an enclosed space. The handles are mounted on a pivot, so hand damage from a small job will be minimal.

It takes a few minutes to get the hang of it, but after that, it goes quickly.

ron in sc
04-20-2007, 07:22 AM
Sound like my helper will be able to do this without much trouble. I was able to break cement with an 8 lbs. sledge hammer, so the electric jackhammer should be fine.

Below is a photo of what we need to remove. It's about 110 sq. ft. We have to remove because foundation of garage will extend into area. We are having to move detached garage closer to existing house to meet requirements of tree protection ordinance that deal with tree protective zones and setbacks that deal with grand trees.

Junkman
04-20-2007, 09:32 AM
Why not just let the contractor that is digging the foundation with a backhoe remove them. It will take all of about 5 minutes and once he lifts the first one, it will crumble and the rest will follow. If he has to truck the material that is dug off site, he can take the broken concrete pieces with the dirt. It will save your back, and I doubt that he would even charge extra for the lifting of the concrete. Might charge you a small amount for disposal.

ron in sc
04-20-2007, 10:24 AM
Why not just let the contractor that is digging the foundation with a backhoe remove them.

I want to use the concrete for fill in another area on the property where I'm altering the grade.

Junkman
04-20-2007, 12:37 PM
I want to use the concrete for fill in another area on the property where I'm altering the grade.

Assuming that the contractor is going to be bringing in a backhoe to dig the foundation, he can bust up the concrete, and scoop it up with the front bucket and deliver it where ever you want it on the property. My experience is that contractors are very accommodating to the homeowner when you hand them a hot cup of coffee the first thing in the morning, and a ice cold soft drink before lunch. Whenever I have anyone working at my home, I always make sure that the frig is loaded with soda and that when it comes to lunch time, that I have made lunch for everyone. They appreciate it and they also save a lot of wasted time going into town to get lunch. At the end of the day, I will even offer them a cold beer, but only after checking with the owner first. Keep your contractors happy, and they will go the extra mile and make sure that every thing is done right. Junk.....

ron in sc
04-21-2007, 05:45 PM
Well that concrete was as thick as 6" in some places. The little walkway in the photo and a very small corner of the driveway was removed. It didn't take my guys long to do it. I certainly would not have wanted to do it myself.

They loaded about 1/2 of the concrete on my trailer and we took it to the dump. The load we took to the dump weighted 4200 lbs. More than I would have expected.

mickeypat
04-21-2007, 06:15 PM
The city hauled that away for free? You must be in a small town that still gives a shit about people. Amazing:thumbup:

66RICH
04-21-2007, 10:10 PM
Population 38,000! The only thing they won't pick
up is roof shingles!