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renosteinke #215755 07/15/15 08:00 PM
Joined: Apr 2002
Posts: 7,381
Likes: 7
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Now there are three votes to call a pro!!

Those expensive diamond core drills go thru anything in any wall I ever encountered.

Sawcutting slabs is a 'ditto'.


John
Potseal #215756 07/15/15 08:21 PM
Joined: Mar 2004
Posts: 947
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twh Offline
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Originally Posted by Potseal


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



Who does that?

renosteinke #215758 07/15/15 09:27 PM
Joined: Jan 2005
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Let's not over-think this.

I mean ... X-ray? Really? We're not talking a pre-stressed concrete floor- we're talking about the typical block wall, where we make countless holes for 3/4" EMT daily.

Nor are we likely to contract THOSE holes out. Yet, just 'brushing' against rebar is enough to ruin a good hole.

I haven't put a ruler on the rebar used in block walls, especially for the "bond beam." Heck, it might be 1/2" some of the time .... but it sure isn't 5/8"! That's a pretty hefty rebar, something I only rarely see, and then in substantial foundation pours. That discussion, misses the point: rebar is sure to be a fraction the size of the hole you're trying to make.

This thread was inspired by a series of holes I needed to make for 3" pipe. Invariably, I'd catch the rebar along the edge of the hole. It's a real puzzler when the holes for pipes #1, #2, and #4 sail clear through ... yet hole #3 manages to catch steel along one edge. You can't move that hole, and even a small 'adjustment' is difficult with the bulk of the hole already made.

So far, I don't think anyone has tried that Bosch 'rebar cutter' bit, in any size. Pity. I suppose I'll have to front the $55 and find out firsthand. If I do, I'll be sure to make a report.

renosteinke #215759 07/15/15 10:47 PM
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Originally Posted by renosteinke
we're talking about the typical block wall,

Actually, I've never seen a block wall with rebar.
However, around here, the flavor of the day is ICF, which has a lot of 1/2" rebar. And the building inspectors have no problem with making a hole through where there's rebar.

renosteinke #215760 07/15/15 11:22 PM
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reno:

OK, time for me to clarify what I said above.....

3" and up holes in concrete (poured) walls (all w/rebar), are what I called the pros for. Also, any saw cutting slabs was left to the pros. (Think a critical hole or cut)

I favored Bosch 'Bulldog' hammer drills, w/SDS bits for holes up to 1". Black & Decker Macho hammer drills for core up to 2". Yes, when the occasional rebar was found, the hole was adjusted as needed, These were not critical holes, so no big deal.

BTW, as Greg said, rebar is common in block walls here; mostly #4 or #5. (1/2"-5/8") Some poured walls have #7, and many spec slabs have #8.



John
renosteinke #215762 07/16/15 04:10 AM
Joined: Jul 2004
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In Florida the tie beam need 4 #5s, there is one in each doweled cell (corners, both sides of any window or door and every 4' on a running wall) and 2 in the footer. These are all wire tied together to make a matrix.
If the beam is load bearing, you may have four #7s and two #5s. Every one of them is part of the engineered assembly and cutting one is about like cutting truss chords.


[Linked Image from gfretwell.com]


Greg Fretwell
renosteinke #215763 07/16/15 09:34 PM
Joined: Apr 2002
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Greg:
Is this a residential, or commercial??

Looks real heavy duty.


John
renosteinke #215765 07/17/15 01:57 PM
Joined: Jul 2004
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My house. Florida has a tough building code ... hurricanes.
I imagine the steel in that beam is probably what the engineer would spec anywhere tho. This is carrying the corner of the roof from a column 5' away. I have a 9x9 corner slider there.
A regular tie beam that is only there for uplift will have four #5s.


Greg Fretwell
renosteinke #215775 07/18/15 03:21 AM
Joined: Feb 2013
Posts: 264
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Like someone already mentioned "rebar in block wall?".

That's new to me, too. I really thought that the OP meant poured concrete with rebar.

Any block wall that I've drilled into there was only one concern and that was hitting conduit or other. Otherwise, draw a circle and use the longest 1/4" bit you can find and drill as many holes as possible. Then knock it out with a hammer.

But if rebar is involved then I can't offer anything since I have yet to encounter block walls with rebar.


A malfunction at the junction
--------------------------------------
Dwayne
renosteinke #215778 07/18/15 04:51 AM
Joined: Jul 2004
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G
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This is a typical block wall in Florida. The pictures were taken to show the UFER connection but you can see all the "hooks" that will form the rebar matrix when the the hooks are dropped in from above and tied to the bottom hooks.
They paint the Ufer green so that cell doesn't get poured solid like the rest

[Linked Image from gfretwell.com]


Greg Fretwell
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