drilling concrete

[Eric]

I need to cut 2 holes in my concrete patio, each one will have a 4x4 stuck in it and then concreted up again so i have a sturdy post. I'm putting in a fence and gate on one end of my patio so i can let my daughter out to play there. I need these holes to be big enough to allow me to move the post a bit to get things to line up right (6" holes?) Anyway, whats the easiest way to do this? What if i hire a contractor, how much do you think that would that cost me? Thanks, Eric

[Fred]

Just did this two weeks ago for my new gate with 4x6s. I drill small holes around a 12" circle with a sds rotary hammer but I couldn't bust out the concrete with it. I brought in a breaker hammer (jackhammer) the next day to break through - 6" of solid concrete slab was the reason. The holes were

2.6' deep done with one of those hand held post hole diggers that turns straight down. Contractors wanted $400 per hole! No thanks. It went pretty fast, about 4 hours for both holes - so I paid myself $200 per hour.

[m Ransley]

Rent an electric demolition hammer -jack hammer for 40$ it will go quick

[George Lucas]

I don't know if you can rent one of these or not, but the easiest way to do it would be a Portable Electric Concrete Core Drill:

one down). I used one a lot when I worked for a materials testing company and had to take asphalt cores to check for road thickness and density. Hook up some kind of hand-pumpable water supply tank, plug it in and it would make short work of your problem. It looks like this model can drill holls up to 10" in diameter. Just make sure to keep pumping so it doesn't run out of water and once the water turns brown you've hit dirt.We had special tongs designed to remove the core once it's cut, but I'm sure you could figure something out to grab it and pull it out.

Greg M

[M.Paul]

Eric, Have you considered drilling 2 small holes for each post and using a Simpson metal 4x4 mount. These are sturdy and they also keep the posts about an inch high off the concrete. I think that this would be easier to install and maintain than digging 2 large holes and setting in concrete. You could use a standard drill with a masonary bit. I bet the bit and hardware would cost less than $20 dollars and it would probably take you less than an hour to drill the holes, install the hardware, and setup the posts. Good luck. M.Paul

[SteveB]

I have done this to mount posts:

Use a 3" x 3" x .120" steel tube post. Weld it to a piece of 12" x 12" x

1/4" plate with four holes, one on each corner. RedHead it to the concrete. Quick, simple, easy.

Steve

[HeyBub]

You can rent them.

After your postholes, drill a hole in a closet for installing a below-floor safe.

[Gideon]

Eric,

If you wish to do this youself, consider the following purchases:

1) Homier SDS drill - $19.99 2) Additional SDS drill bits - about $20.00 from Homier or Harbor Freight

Inexpensive tools work great for occasional small projects.

Good luck, Gideon