What do you do when a surface is too hard to drill through?

[WhatsYourSign?]

We've had a couple installs recently where we were drilling into concrete and after an inch or so, we reached some sort of surface that even our strongest drill bits couldn't make any progress.

I'm guessing there was some sort of steel rebar beneath the concrete that we couldn't drill through, but I'm not certain.


In these instances...what do you do? Do you use Liquid Nail? Do you have some special drill tool that can work its way through whatever is behind the facade? Something else?


Thanks in advance for your help!

 

[rydods]

Depends on what you are hanging. I'm pretty sure they make a mason bit for concrete with re bar. We just did a job with 12" formed plastic letters and even with this particular bit, it's a pain. It will get through but not without a lot of force and you'll need a few extra bits.
Since ours were just formed plastic letters, we drilled as far as we could and had to trim the stud in those spots before applying the adhesive.

 

[Texas_Signmaker]

What are you installing? Is it a concrete wall?

 

[WhatsYourSign?]

What are you installing? Is it a concrete wall?

We're hanging a sign on a monument with concrete backing where the sign is being hung.

It's not lit and there's no power or anything like that which would pose a danger, it's just something stronger than concrete behind the face (likely rebar as mentioned).

 

[Johnny Best]

Not good to drill through rebar, especially if they are precast concrete forms. An inch should be deep enough for an anchor or like was mentioned shorten the stud. Is this on all the holes you drilled or just one place because rebar is a rod shape so it would not be all over, Maybe the monument goes all the way to the ground and then they put concrete over that. Then your dealing with the cast material maybe like bronze which I would not drill into either. You need to find another method to hang the signs.

 

[ddarlak]

without knowing if you were using the correct tools I would say it's either a stone or rebar.

if it was rebar, put a regular bit in and see if you can cut into it. if that don't work, then it's a stone and your equipment isn't up to the task.

 

[JTBoh]

If it's harder then concrete, it's stone or rebar.
Most likely rebar. You can use a few cobalt bits after the concrete is out of the hole and drill it with enough force. It's not going to affect any structural integrity.
If it is stone, diamond hole saw bits will eventually chop right through it.

 

[fresh]

are you using an impact hammer drill?

 

[Reveal1]

Same question as fresh; we use a rotary hammer drill and quality bit; a conventional hammer drill is a toy.

 

[Texas_Signmaker]

I'm still not getting enough information to picture this install. How heavy is the sign? What size? What is it made of? Is it flat ACM or pan shaped aluminum? Dimensional letters? What are we dealing with? What kind of fasteners are you using? Can you give more information?

 

[flyplainsdrifta]

GET A BIGGER DRILLLLLLLLLL!


sorry couldnt resist. id see if the cust has any idea of the makeup or see if you can get in contact with the company who put the monument together to get an idea of whats up.

 

[Brandon708]

You need a rotary hammer drill with a bit made for going through concrete with rebar. You can go to home depot.
https://www.homedepot.com/p/Milwauk...2-5-0Ah-Batteries-Hard-Case-2712-22/205563065
https://www.homedepot.com/p/Milwauk...er-Drill-Bit-Kit-5-Piece-48-20-7498/206797938

You will drill your holes in like 5 seconds each.

 

[Gino]

Like Brandon said, you need an SDS drill. They'll cut through most anything, except rebar in seconds. If you don't get through, use a regular drill bit and try to drill through it.

 

[equippaint]

Are you using a masonry bit? Why would you even consider liquid nails to hang a sign or use to anchor a fastener in a wall? With all due respect, not knowing what you are doing is potentially dangerous for others. I guess this is why many states require a contractor's license. I know people do it but you need to be careful randomly drilling or cutting through things when you don't have a clue what it is..

 

[Texas_Signmaker]

Are you using a masonry bit? Why would you even consider liquid nails to hang a sign or use to anchor a fastener in a wall? With all due respect, not knowing what you are doing is potentially dangerous for others. I guess this is why many states require a contractor's license. I know people do it but you need to be careful randomly drilling or cutting through things when you don't have a clue what it is..

I agree wit-chya.

Everyone's response is "drill it drill it!"

Was hoping OP could head some light on the details...Might have a better option for him or her.

 

[Billct2]

Definitely need more info...but from the meager description it sound like it's not a large sign. If I could, I would add more studs and use epoxy, both in the holes and on the back of the sign

 

[Moze]

You're hitting rebar.

Use Bosch Bulldog Xtreme bits. They'll go through rebar without issue, assuming you're using a decent SDS rotary hammer (and it WILL cut through rebar in seconds).

You're not going to hurt the concrete by drilling the rebar.

No cobalt or diamond bits needed.

No regular bit needed.

And for crying out loud, don't ask the customer if they have any idea of the makeup of the sign or who made it. Seriously?

This isn't rocket science......it's drilling a hole in concrete.


The one exception is if you're drilling in concrete that contains post tension cable. In which case, you need to run the other way.