What do people use to patch those abortive attempts to get through the ICF wall?

You know; where the services (plumbing, electrical, HVAC, etc) go to rotohammer through a wall, get 4" in and hit rebar?

Has anyone found something they like to fill those holes with, first in the concrete and then, I guess you'd just foam the surface hole?

What about sealing around the conduit inserted into the holes they do manage to drill?  Anyone use anything other than just foam for those?

Well if you miss putting it in before you pour, use hydraulic cement with a grout bag

Well if you miss putting it in before you pour,

?? I'm talking about using the roto-hammer to penetrate a finished concrete wall. If you hit rebar, you need to start over, leaving a large concrete and foam cavity.

I did find non-shrink grout by Googling hydraulic cement and grout bag, though. I might give that a try. Thanks!

Most I've seen just cut the rebar. For patch, use a modified non-shrink patch. The epoxy types are good.
If sealing around the conduit, I'd use a good, flexible sealant (think expansion joint material)

If you hit bar, the hole just takes 2-3 times as long to get through.

Most I've seen just cut the rebar.

Sorry to have to ask this, but how do you cut #5 Grade 60 rebar at the bottom of a 4" deep 1-3/8" hole?

For patch, use a modified non-shrink patch

OK, sounds good.

(think expansion joint material)

I've only ever used those fiber boards. Got a tradename on the sealant or expansion joint material that you like?

Thanks for the assistance.

If you hit bar, the hole just takes 2-3 times as long to get through.

What kind of a bit are you using?

Hilti, Bosch

The secret is to not let bit bounce or jump, just hold constant pressure and it will get through the bar, just slow and all the teeth will still be on the bit when done.

#4 bar is not bad, if you hit #5 go grab a few sodas cause you will be there for a while.

We did a house back in the spring, I missed 2 holes (actually City has it's own rules compared to everywhere else) and the mechanical contractor missed 6. I just rented a bolt-on core machine, cost $ 300.00 with the 5 & 6" bits, bought some 7" sleeve anchors (longest I could find at HD) and we done in under 3 hours. It was a wet coring machine which is really nice, each hole took under 10 mins. cutting though rebar, these were 6 & 8" ICF walls.

just slow and all the teeth will still be on the bit when done.

Huh? A masonry bit pulverizes concrete through impacts and then removes the dust. You can't pulverize steel and the heat from friction ruins a masonry bit.

Hilti and Bosch are brand names. Each probably has more than a dozen different kinds of bits.

You said 1 3/4" hole, that is a core bit, not a masonry bit.

It can be cored, even with rebar, slow and steady and it can be done, I have done it but like I said it is slow and you can do it without damaging your core bit.

If you are in a rush, rent a wet coring rig and drill a 3" hole, insert your pipe and grout around it. This is the fastest way to cut through a piece of #5 gr. 60 bar.

You said 1 3/4" hole, that is a core bit, not a masonry bit.

Look again. I needed to drill about 30 1-3/8" holes for 1" conduit penetration. Because I own a hammer drill and a bit, I'm not in a hurry to run down and engage a coring machine.

The original post was about how to patch the abortive holes that you get when you can't get through rebar.

BTW, I have a 1-3/4" masonry hammer bit, too.

The patching is the easy part, we got that covered...

30 holes...that's a lot of holes, just an opinion...after you shoot someone for forgetting all those I would look at the renting of a coring machine, merely for the time saving factor, much faster then a regular roto hammer.

Hilti does make a SDS 1 3/8" bit that will eat through rebar, I'm going to guess at $ 150.00 for the bit, you may need 2 for that many holes if you are hitting rebar and damage it. And you could be literally days drilling if you are hitting rebar.

try Hilti part # BIT TE-Y GB 1 1/2-23 or TE-YX 1-3/8" x 23" Hammer drill bit

Can you not avoid the rebar? I just poured my basement and I know within +/- 2" where every piece of rebar is located just by looking at the where the ICF ties are located.

What do you need 30 penetrations through your wall for?  If just some type of electrical wiring, why not just drill 1/2" holes through the concrete.  Much easier to drill a 1/2" hole than a 1+" hole.  Do you really need conduit through the concrete?  If it is some sort of electrical wiring, you should be able to cut out the foam for an electrical box on either side of the penetration, secure the box with construction adhesive and/or tapcons, drill a 1/2" hole in the back of the box to line up with the hole in the concrete if it doesn't already have a conduit knockout in that position, run your wires through the boxes, then seal the holes in the concrete with RTV silicone.

Can you not avoid the rebar?

On 2 out of 3, sure. :-)

These holes are at the base of 16'-18' walls and the bottom ends of the vertical rebar get a bit wiggly when you are shoving them down that far. There was a lot of steel and it got crowded in there.

Do you really need conduit through the concrete?

These are nearly all below grade.

What do you need 30 penetrations through your wall for?

Lots of low voltage stuff and we wanted to keep the runs as short as possible, ergo go under - more direct.  Coming up out of a basement equipment room, each conduit has to pass through the garage, so that's two for each run and some then have to go outside yet again which makes three penetrations for some runs.

try Hilti part # BIT TE-Y GB 1 1/2-23 or TE-YX 1-3/8" x 23" Hammer drill bit

Chris, can you guess why those coring bits are spec'ed for drilling into unreinforced concrete or masonry?

I just pulled them off the website, contact them, as I know they have rebar eaters...I have bought them myself many years ago

Is it not possible to come out in one location then run through the foam once you get out, or is that making your runs too long?

Is it not possible to come out in one location then run through the foam once you get out, or is that making your runs too long?

Exactly. That's what makes runs much longer than they need to be.

Posted By ICFHybrid on 14 Aug 2011 12:39 AM

These holes are at the base of 16'-18' walls and the bottom ends of the vertical rebar get a bit wiggly when you are shoving them down that far. There was a lot of steel and it got crowded in there.

Ah, ok.  I used short pieces of 1-1/2" pvc pipe as collars over my rebar dowels coming out of the footing and then dropped the verticals down into those collars to hold them in place, then I tie wired the top of the vertical rebars to the top horizontal bar to hold them in place.  My rebar also is 16" oc vertical and horizontal, so it would be pretty easy to avoid the rebar if I needed to drill a hole in the wall.

Do you really need 1" conduit? What size and number of wires are you running through these penetrations?

You can get schedule 40 grey 1/2" PVC conduit with an ID of 0.60" and and OD of 0.84". Then you would only need to drill a 7/8" hole through the wall - much easier than drilling 1-3/8" holes and less likely to hit rebar. Even 3/4" conduit with an ID of 0.80" and OD of 1.05" would allow the use of a 1-1/8" drill.

The electrician thought 1" conduit would be safe. He did call out a few for me to drill for 3/4" conduit.

I think he was worried about the wire pulls. There are some long pulls.