Aggression therapy (aka busting up a concrete slab)

By JimRental

OpenRental note: P. and K. Goyle (yes, those are pseudonyms) are undertaking a series of projects in their yard. We'll follow their progress through P's blogs, as they utilize a range of rental equipment to transform their yard into a stylish oasis.

Like a hot knife through butter…

That’s the feeling of having a concrete cutoff saw slice through concrete. As a set-up to the jackhammering, I needed to separate the driveway from the garage, and the walkway from the house, to avoid any potential damage to the structures. The concrete cutoff saw did so more easily than I anticipated.

You have two basic ways to approach a cutoff saw – with or without water. If possible, hook up the garden hose, and go with the water. It not only helps the saw slice more easily through concrete, but also keeps the dust down.

The saw itself isn't very heavy, and easy to use. Equipped with a two-stroke engine like a chainsaw, you just fire it up, turn on the water and start to saw.

I found that the easiest method of sawing was to place the saw on the ground, and tip it forward on the two front pads. This tilts the cutting blade down and into the concrete. Once it hit the desired depth (in my case, about four to five inches), I slowly pulled the saw backwards gently and steadily, while continuing to cut. It's really that simple.

One note of caution: I wouldn’t recommend picking up the saw while the blade is moving at high revs. That’s quite a bit of spinning weight, and very difficult to control.

Like a vibrating massage chair through butter…

Once the cutting was done, all that was left was breaking the slabs into smaller pieces.

It’s not difficult, but it is tiring. Three-and-a-half hours with the 60-pound breaker hammer left me feeling like I had been worked over by the chief masseuse for the former East German Women’s swim team.

To begin, I inserted a cutting bit, and ran the heavy-duty extension cord provided by the rental shop from the hammer to an outlet. Then stand the beast up and get to hammering!

I started by breaking down (pun intended) the driveway slab into small, more mentally manageable 4' x 4' sections.

I worked back and forth across a section until the slab was in bits. Here's how it went: Set the breaker hammer in place. Hammer away. Pick up the hammer. Reset it. Hammer away. Pick it up again. hammer away. Repeat. And repeat. And repeat. Crude, but very, very effective.

By the time I was done, I felt like I'd done about a thousand 60-pound bicep curls. But, as long as you pace yourself, and protect the back by lifting with your knees, you can make short work of a slab.

Ideally, the concrete in my driveway would have broken down into medium-size bits. Unfortunately, I got many smaller pieces, which I think is a reflection of the age of the concrete.

Things learned:

1. Take your time. The process of picking up, repositioning, placing, then activating the breaker hammer is tiring. Keep the sections you're working on small and manageable.

2. Double up the ear protection: These things are LOUD! Heavy-metal-head-banging-music-concert loud! There’s no getting around that. So protect your ears with a double helping of sound insulation. In my case, I first used foam inserts I picked up at a local industrial safety equipment store. After about two minutes, I added over-the-ear hearing protection as well. Definitely the right call.

3. Watch your feet: It would be all too easy to pull the jackhammer quickly out of one hole and swing the blade closer to your foot than intended. I’m guessing that since a breaker hammer breaks concrete, it could do the same to your foot!

4. Whether it's goggles or safety glasses, eye protection is a must! Look…you’re breaking up a hard substance with a tool that's basically a robo-sledgehammer. Chips of concrete will fly in unpredictable directions. Protect your orbs accordingly.

5. Let the water from the concrete saw evaporate before starting on the jackhammering -- let’s just say the combination of concrete-infused water and an active breaker hammer can lead to a bit of splatter – in my case, all over the garage doors.

6. The bigger the area to be demolished, the more cut lines you should make with the concrete cutoff saw. You don’t have to go crazy, but making a cut completely across the width of the driveway or walkway every four to six feet allows more room for the concrete pieces to break away when hammered.

7. Bigger is better. In this case, more room provided by additional cuts with the concrete saw would have allowed the concrete to break into bigger (but manageable) pieces. That translates into a bit less hassle when it comes to disposing of the broken concrete.