I am finishing our basement and adding a bathroom. The builder did not stub in the drains so I have to do this.

What do you recommend I use to break up the concrete floor where I'll be adding the sewer and shower drains? I was thinking about renting an electric jack-hammer. I had also considered a concrete saw but the dust would probably be too much.

Any advice on tackling this project? Thanks.

Hey Augy,

You're going to have dust no matter which one your use. Having said that, we use a electric jackhammer to break up the slab. Good luck, Tom

I tackled that project already and agree with Tom, rent the jackhammer. The saw creates far more dust and takes longer to settle. I used a jackhammer and was done within a fraction of the time. But beware, they are HEAVY! For future reference, if you ever need to get grout or mortar out, without damaging tiles or whatever the product, the saw is faster and makes cleaner lines.

Consider both... I recently did this very same project. The saw you can rent from HD actually has a hose attachment and the water really keeps the dust down. Then with the jackhammer you can work out the pieces fairly quickly.

You mentioned renting the electric jackhammer, not sure which one your looking at, but consider the Hilti TE-905... great tool.


Scott

The cheap little saw I rented at HD didn't come with a hose attachment. I poked a hole in a milk jug and let the water leak on the job.

I'm going to tackle this project this weekend. I'm not sure why I would need both tools (jack-hammer and conc. Saw) though. I've never done this type of job before so maybe there is something I'm not considering? Dust is a concern though as there is some finished areas already in the basement so I'd like to minimize it as much as possible.

I need to bust up 3 areas roughly 1' x 2' each. Any idea on how long that will take? I'm curious to know so I can estimate how long I'll need the rental tools.

Thanks for the advice.

Hi Augy,

"I need to bust up 3 areas roughly 1' x 2' each. Any idea on how long that will take? I'm curious to know so I can estimate how long I'll need the rental tools."

If I were running a trench for any length I'd use a jackhammer but for smaller cuts such as yours I would use a Skill Saw and masonry blades. For a four inch pour figure about 1/2 hour on each cut to saw through the cement and wire mesh and break the cement out of the cut. Wear a dust mask when you make the cut. Good luck, Tom

When you go out to rent the jackhammer don't rent the biggest most expensive one they have, just get a "kango" or a smaller "hilti" jackhammer. Its much easier to use and will do the job considering most residential slab is only 2" - 4" thick. You could also get away with using just the kango if you make sure the bits they give you have a nice fine edge on them and if you clean up the edges of the concrete before you patch the slab.

Augy123,

I used both tools when I did this. The reason is that my slab is very old, and already has a few cracks. Also it does not have any steel reinforcing mesh in it. I figured that if I used just a jackhammer, I might crack more than I bargained for. I cut the outline with the saw, but only about halfway to 3/4-way through the slab. Then it was easy to break the pieces out with the jackhammer and I didn't worry about cracking the rest of the slab. This method made a very clean square cutout that was easy to fill in later.

If my job had allowed me to cut an entire square with the saw (all 4 sides), I think I could've skipped the demo hammer and just used a good-old-fashioned sledgehammer. But I had to get into a corner and the job went a lot faster with the Hilti demo hammer.

Rental cost for both of these for half a day was reasonable, something like $80 for the pair.

I did have dust EVERYwhere, so if you can find a saw with the hose attachment, rig a milk jug, or even have an assistant hold a garden hose on the blade as you work, it'd help a lot I'm sure.

Good luck with it!

Ok, thanks guys for the help. I'm going to rent the jack-hammer and use my circular saw with masonary blades to cut a clean edge. I'll post back for others reading this to describe how things go.

For a couple of little spots like that, you might just use a sledge hammer. Sorry if I am too late.

Thanks for the advice everyone. I used a Bosch Power Hammer to bust up a trench about 1 foot wide by 12 feet long. The hardest part was removing all the concrete chunks! Dust wasn't too bad... at least nothing like with a saw. Still, there is a lot of it and you really need to put up plastic in the work area.

Anyway, the jack-hammer worked great and I was able to bust up the floor, install the new sewer lines, and patch the concrete in a day and a half. I wasn't too concerned with how the patched concrete looked as I'll be laying carpet and tile over it.

Again, thanks to everyone for offering their advice. It wasn't nearly as bad a job as I had feared ;)

Augy,
"It wasn't nearly as bad a job as I had feared."

It never is once you take the unknown factors out and replace them with knowledge. Kudos on a job well done. Tom