You can try the sledge but may take you a while. I would probably just suck it up and rent the breaker. Faster and easier on you.

Is it poured concrete or concrete block?

If it's poured concrete as millworkman said would be easier and faster with a breaker, if it's is a concrete/cinder block sledgehammer will to the job and by the time you make the trip to rent one it will be all broken up, not to mention if you in a decent shape its a good exercise and lots of fun to bust it up.

it is poured concrete and in good shape too. Any suggestions on what size breaker to rent from HD? Would the smaller one do the job? Or maybe go with the recommendation of the rental shop?

They have a 35LB, 46.5, and 90 ft-lbs of the impact... the 46.5 LB its good for slabs up to 6" thick.

Before you go hit a few spots with a hammer and see if the sound and feel is solid or semi-hollow if semi-hollow maybe a 36LB hammer will do the job its a little lighter.

See what the price difference, maybe getting a heavier hammer will do the job faster and you will need 1/2 day rental. (not sure who is doing the job and how they can handle the tool.)

Good luck

that's a good idea - thanks! I'll try my sledge on a corner and see what happens. I plan on doing all myself.

As the step is 10" thick, it sounds as if I would need the 90 ft-lb hammer if 46.5 ft-lbs is only good to a 6" slab? Or is the small nature (1 yd X 1 yd) of the 'slab' significant to the size rented?

How tough is a concrete step? Do I stand a chance of drilling a hole with a masonry bit and breaking off a chunk with a wedge? Then repeating until I have the whole step demoed?

Just get the hammer and you will bust the entire porch before your coffee gets cold :-)

jaansu2- Rent the breaker instead of wasting hours of your time like a convict doing hard labor with a sledgehammer. And the idea about drilling holes in the steps to facilitate pounding away at it...plan on adding a couple of days to the project. I used to try to do things on the cheap, but learned my lesson the hard way that cheaper ain't better with concrete removal.

To break up a thick step like that you need to have a very strong impact to get the cracks started. If you are feeling strong you can probably do it with a good sledge hammer, but don't be surprised if it takes a dozen blows just to get the first good crack in the top of the stoop. Using the jackhammer is much easier.

You can always experiment by taking your sledgehammer out and whacking the top of the steps about six times near one edge to see what happens. You will find out how much more cardio intensive it is than you expected, and you will get an idea of whether its feasible to keep on with using manual tools.

The specs for the jackhammer that state it handles up to a 6" slab probably assume you are trying to punch through a 6" slab, but in your case you are going to be chipping off around the sides. It may be a little slower, but should work fine.

Bruce