# Drill 4" hole in concrete floor beam



## kevst7 (Nov 24, 2016)

I am working on a townhouse that is two floors and the second floor is concrete. The unit is about 22 feet wide x 45 feet deep. It doesn't have any load bearing walls inside. The concrete for the second floor is a 4" slab with 12" beams that drop down every 4 feet. They are supported by the exterior walls. I am rearranging the kitchen and would like to move some drain pipes that were in a drop ceiling. I would ideally want the first floor ceiling to be flush without having to make any build-outs around any pipes. My plumber says to drill about a 4" round hold into two of the 12" concrete beams so we can raise the drain pipes and allow the ceiling to be flat. I wasn't sure on the structural impact this might have. If this is fine to do, then that is the route I would like to take, but I do not want to compromise the integrity of the concrete second floor. I have attached a picture of what it's like. Any help is appreciated.


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## MikeFL (Oct 7, 2016)

No.


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## rjconstructs (Apr 26, 2009)

You're kidding right? This is your first post and you come here to ask a structural question to an internet forum. If someone said "yes, no problem", and there was a catastrophic failure, what then? Who's fault? Mike said, "No". Now what? Are you looking for an average number of "No's" or even "Yes's"? Then you base your decision on that? I wouldn't.


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## Inner10 (Mar 12, 2009)

I'd tell the plumber to drill his own hole...

Sent from my Nexus 6P using Tapatalk


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## sunkist (Apr 27, 2012)

Wow HVAC and PLUMBERS drill a hole here cut a truss there !!!.
Drilling (coreing) a 4 inch in hole in that flooring beam would be madness.
Mike's answer short and sweet "NO" is the right answer


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## kevst7 (Nov 24, 2016)

MikeFL said:


> No.


 Thank you for your answer.



rjconstructs said:


> You're kidding right? This is your first post and you come here to ask a structural question to an internet forum. If someone said "yes, no problem", and there was a catastrophic failure, what then? Who's fault? Mike said, "No". Now what? Are you looking for an average number of "No's" or even "Yes's"? Then you base your decision on that? I wouldn't.


 No I wasn't kidding and yes this was my first post and I am asking a structural question. I am not basing my decision on more yes or no answers. I honestly think your reaction is a little ridiculous. This is a professional forum, is it not? So since this isn't my forte, I figured maybe someone could better help me out with this. It did seem kind of wrong for holes that large to be drilled into the concrete, but I didn't know if maybe someone with more knowledge had a rule of thumb that is a standard within the trade or something of that nature. That is why I posted the question here. Definitely not to tally yes and no's and go with the answer that way. 



Inner10 said:


> I'd tell the plumber to drill his own hole...
> 
> Sent from my Nexus 6P using Tapatalk


 :laughing:



sunkist said:


> Wow HVAC and PLUMBERS drill a hole here cut a truss there !!!.
> Drilling (coreing) a 4 inch in hole in that flooring beam would be madness.
> Mike's answer short and sweet "NO" is the right answer


 It seemed off to me too and I wanted to confirm that I wasn't missing something.

Thank you all for your answers.


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## FrankSmith (Feb 21, 2013)

Should be no problem as long as you follow the regulations. Temporarily support he beam. Drill a hole and epoxy a steal column cut the width of the concrete beam. You will have to drill a larger hole to account for the steal if you need 4" pass through. The steal epoxied in place will be stronger than the concrete removed. This happens all the time. Take a look around in a parking garage.


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## FrankSmith (Feb 21, 2013)

I was just kidding. I have no idea. Just wondering if I could make you think it was a good idea.


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## greg24k (May 19, 2007)

I wouldn't drill, takes to much time... just bust an opening with a jackhammer and let us know what happens if you live to tell:laughing:


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## Calidecks (Nov 19, 2011)

Yes, no problem. 

________


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## Lettusbee (May 8, 2010)

Was on a hospital Reno way back when. Had to rent a hilti scanner prior to coring the floor. Big fuss over making sure we didn't core through the tension cables. Only problem, nobody bothered to see if there was an occupied patient bed underneath the core. Missed the poor dude by three feet. For the record, I was not involved in this process.


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## rrk (Apr 22, 2012)

I know someone who does concrete coring, they do it all of the time. But they do not identify where to drill, the engineer does or the manufacturer does. There is usually a dimple or a pin in the areas they can core. There is lots of paperwork he keeps from the engineer in case there is a problem.


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## sunkist (Apr 27, 2012)

Lettusbee said:


> Was on a hospital Reno way back when. Had to rent a hilti scanner prior to coring the floor. Big fuss over making sure we didn't core through the tension cables. Only problem, nobody bothered to see if there was an occupied patient bed underneath the core. Missed the poor dude by three feet. For the record, I was not involved in this process.


I wonder if the PE/PLUMBER has a scanner to c/k for tension cables or rebar ?, may just have x ray vision :laughing:


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## sunkist (Apr 27, 2012)

Inner10 said:


> I'd tell the plumber to drill his own hole...
> 
> Sent from my Nexus 6P using Tapatalk


Now thats funny :thumbup:


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## calmod (Aug 16, 2011)

You could be in court for a very long time if you don't have a serious paperwork trail on that with engineers, inspectors, HOA, etc etc. The engineer above said no and you should listen. Anything is possible if you throw enough money at it but I would be getting creative with plumbing first. I don't drill any holes at all in structural concrete without a full review by an engineer.


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## Inner10 (Mar 12, 2009)

Lettusbee said:


> Was on a hospital Reno way back when. Had to rent a hilti scanner prior to coring the floor. Big fuss over making sure we didn't core through the tension cables. Only problem, nobody bothered to see if there was an occupied patient bed underneath the core. Missed the poor dude by three feet. For the record, I was not involved in this process.


A coring company was on site to drill holes for an office fit up. He wet cored a hole right ontop of an office full of computers. Didn't even think to look at the floor below. Luckily a single ceiling tile was the only victim.


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## platinumLLC (Nov 18, 2008)

Lettusbee said:


> Was on a hospital Reno way back when. Had to rent a hilti scanner prior to coring the floor. Big fuss over making sure we didn't core through the tension cables. Only problem, nobody bothered to see if there was an occupied patient bed underneath the core. Missed the poor dude by three feet. For the record, I was not involved in this process.





Inner10 said:


> A coring company was on site to drill holes for an office fit up. He wet cored a hole right ontop of an office full of computers. Didn't even think to look at the floor below. Luckily a single ceiling tile was the only victim.


I worked for a large commercial steel stud/drywall/ceiling company and about 15 years ago we were just about to finish up our 10 hour day at a new building at a college when I get a phone call from the office saying a ceiling just fell down at a shoe store in the mall. He asked if I could try and round up a few guys to put in some overtime and go see what we could do. Ended up getting a few guys to work and some guys from other jobs came to help. When we got there it was a disaster. An electrician decided to core a hole from the floor above and let the core drop and it took out over 2500 square feet of ceiling. The core hit in the middle somewhere and it just all caved in after that when it pulled away from the wall. A 2x4 light landed on a lady. Tiles and grid everywhere. 

We got it all cleaned up and about half the new grid up around midnight and called it a night. The store owner was still there and he was having a fit that we were going home. Told him we had 18 hours in that day and were not going to work any longer. Told him we would be back at 5 in the morning and he should be able to open around 10 or 11. He wasn't happy which I didn't understand because his normal hours were open at 10. I thought that was pretty good to get a call at 4PM and have it back open in the morning at close to normal hours. We got it all done and cleaned up and he opened on time.

It is crazy that some people just start drilling core holes without knowing where they are going to fall or have someone under there to catch it.


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## rustyjames (Aug 28, 2008)

That person doing the core drilling probably figured the core would stay in the core drill bit. It must have been a good size core to bring down that ceiling like that. 
Could have been worse, at least it didn't take out a sprinkler head. I've seen that happen, you won't believe how much nasty, black, Rusty water can come out of one before it gets shut down!


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## Inner10 (Mar 12, 2009)

rustyjames said:


> That person doing the core drilling probably figured the core would stay in the core drill bit. It must have been a good size core to bring down that ceiling like that.
> Could have been worse, at least it didn't take out a sprinkler head. I've seen that happen, you won't believe how much nasty, black, Rusty water can come out of one before it gets shut down!


And the pressure is so damn high after the pump kicks in that you can't even put a bucket over it, it just splashes out.


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## platinumLLC (Nov 18, 2008)

rustyjames said:


> That person doing the core drilling probably figured the core would stay in the core drill bit. It must have been a good size core to bring down that ceiling like that.
> Could have been worse, at least it didn't take out a sprinkler head. I've seen that happen, you won't believe how much nasty, black, Rusty water can come out of one before it gets shut down!


We never did figure out exactly how it took out the whole ceiling but figure it must have hit a 2x4 light or a main tee and was enough force to pull out at least a couple anchors to let the middle of the ceiling come down enough to pull it away from the wall angle. Figured with everything shifting and bending and the weight of the lights it was enough to just let go. Also didn't help that their wires were only wrapped once or twice so they came undone pretty easy. I wish we would have had camera phones back then so I would have had some pictures.

I've also seen a sprinkler head get busted. Like you said it's a nasty mess.


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## Krok (Jul 9, 2016)

> a rule of thumb that is a standard within the trade or something of that nature.


"If one does not know what they are doing, the best idea almost always is to not do it."


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