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#215737 07/11/15 08:48 AM
Joined: Jan 2005
Posts: 5,316
Cat Servant
I have it!

Yup.... Hand mr a roto-hammer, point me at a block wall, and I'll find the rebar, at least three tries out of four.

So ... here's the question ... anyone have any tricks for cutting rebar in the wall? My carbide core bits barely scratch it. There isn't room for a saws-it-all to get in there, and a cutting torch isn't part of my kit (maybe it needs to be!) Hole saws need a solid center for the pilot to guide the bit - and by the time I find the rebar, I've taken the center away.

Yesterday's project involved connecting an MCC to the gutter on the opposite side of the wall behind it. It's not like I could move the holes over an inch.

renosteinke #215739 07/11/15 12:57 PM
Joined: Jul 2004
Posts: 9,677
Likes: 9
Diamond tools will cut rebar but it is very hard on the tool.

Greg Fretwell
renosteinke #215740 07/11/15 02:26 PM
Joined: Mar 2004
Posts: 947
twh Offline
Depending on the size of the hole and the distance between the re-bar in both vertical and horizontal directions, it's probably unlikely that you could drill a number of holes and not hit re-bar. Sorry, but it might not be a super power. Still, you can change your name to "Rebar" and everyone will understand.

When the hole location has to be exact, plan for failure and hire someone with one of those wet coring machines. They cut re-bar nicely. They also do a sweet job of cutting hidden conduit in the cement.

It seems to me that if you stick a torch in a hole that isn't all the way through, it doesn't work.

renosteinke #215743 07/12/15 12:53 PM
Joined: Dec 2000
Posts: 4,289
Some tool rental outfits rent core drills.

United Rentals is one of them. I see there is one in Blytheville.

Make sure to get the damage waiver (insurance).

renosteinke #215744 07/12/15 05:12 PM
Joined: Jan 2005
Posts: 5,316
Cat Servant
I see that $55 will get me a Bosch bit that is specifically designed for cutting rebar, and fits in the hammer drill:

Bosch RCSS2168

The idea seems to be that you use the usual masonry bits until you hit steel, use these bits to cut the steel, then resume with your usual bits. Interesting.

Has anyone used them?

A 1-1/8 bit ought to fit neatly into the hole you're making for 3/4" pipe. Looks promising.

For larger holes - my current project involves 3" pipe - I bet you can make smaller holes to the side of the main hole, cut the rebar, then break it out. Maybe. If you're going to do that, you probably want to remember that most rebar you'll find in block walls is about 3/8" diameter; maybe a smaller bit is in order.

I don't object to renting tools - core drills, btw, are also rented by Home Depot - but there is a time penalty. This job is just outside Memphis, so rental access is no problem.

renosteinke #215747 07/12/15 08:22 PM
Joined: Apr 2002
Posts: 7,288
Likes: 4
As twh said, the core drills from the guys that do core & cutting work real great.

Mark out the location(s), make the call, watch them work, & pay the fee.

Works really painless & great.

renosteinke #215748 07/13/15 12:10 AM
Joined: Jul 2004
Posts: 9,677
Likes: 9
I am not sure whee you see #3 rebar used for much of anything except the bottom and sidewall grid in a swimming pool. A doweled cell (block core poured solid) in Florida requires a #5 that hooks to the footer steel and the tie beam steel on top.

Greg Fretwell
renosteinke #215751 07/14/15 08:13 PM
Joined: Jul 2008
Posts: 98
If you're interested in a dry diamond core bit, I've received good service from this place:
But as Greg said, it is very hard on the drill. I'm pretty sure that I killed my Bosch.

Actually I have considered buying a proper water cooled Hilti core drill and offering my services. Anybody here know anything about that type of business?


renosteinke #215753 07/15/15 01:38 AM
Joined: Feb 2013
Posts: 264
I used to work with a smaller construction outfit that tried doing their own core drilling. Eventually two things happened:

(1) depending on the location we first called in a guy to X-ray the wall or floor

(2) next we called in the guys who specialize in drilling cores

Worth every cent.

A malfunction at the junction
renosteinke #215754 07/15/15 10:17 AM
Joined: Jul 2004
Posts: 9,677
Likes: 9
Pot seal has a valid point with the X-ray. If that rebar was not part of the engineering of the building, the builder would not have put it there. That is particularly true in floors.

Greg Fretwell
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