Running power thru metal

[fourjeepin]

In my basement, I am drilling holes thru the beams to pull the power wires thru as they currently drape underneath the structural members. I wondered why al the wires were drilled thru except at these two spots until I looked closely and found a nearly 1/2" plate sandwiched between two oak 2x12s. House was built in 1953. I will be running one 14/2 and one 14/3.

That's the background. Questions are
1 - how big should the hole be? I currently have one side drilled to 11/16 and the other to 1/2.
2 - do I need to do anything to make this be up to code?

Now for the pics! Note the old wiring with the black fabric like covering. It does not have a ground wire and I have been slowly pulling it out and replacing with Romex.

 

[fourjeepin]

Can't get more than one image to load at a time. Sorry!

Previous image was view from below. Here is the end view.

 

[fourjeepin]

And now the view from straight on. You can see the hole that I have been working on here in this image.

 

[rockwithjason]

why can you not go around the beam as the original wireman did? personally I wouldn't drill this beam, I would drape it or box it in

 

[fourjeepin]

why can you not go around the beam as the original wireman did? personally I wouldn't drill this beam, I would drape it or box it in

Good question. Originally they went under as seen in the first picture. Going around is possible, but would have to occur twice as I am running three way switches on either end of this long, narrow room. Your suggestion would add more wire and I am almost done drilling these holes.

 

[teamextreme]

they went around it and didn't drill the beam because it's a code violation to do so. That's a structural beam that's not allowed to be compromised by drilling through it.

 

[nolimits76]

Granted, we work on bridges, but welding or cutting a beam is a big no-no. As such I would advise against you drilling/torching that beam until you get a professional engineering opinion (in writing) that is okay to do so.

 

[LS6 Tommy]

they went around it and didn't drill the beam because it's a code violation to do so. That's a structural beam that's not allowed to be compromised by drilling through it.

Granted, we work on bridges, but welding or cutting a beam is a big no-no. As such I would advise against you drilling/torching that beam until you get a professional engineering opinion (in writing) that is okay to do so.

X3...

Tommy

 

[sberry]

That little hole in that beam wont mean squat, anyone think this is that closely engineered? But,, any steel with wire passing thru it needs to be grounded.

 

[teamextreme]

Is it that closely engineered that it will structurally fail by drilling a hole? No.
Will there be any issues if a small hole is drilled in the beam? No.
Is doing so an industry accepted practice? Absolutely not.
Is doing so allowed by code? Absolutely not.
Would a building inspector be ok with this? Absolutely not.
With this info, you can make your choices as you see fit, but I know what I would do.

 

[Falcon67]

I would bend up some conduit to protect the runs and route around the beam, personally. that's 4 90s but it's still only 14 gauge wire.

 

[sberry]

Is it that closely engineered that it will structurally fail by drilling a hole? No.
Will there be any issues if a small hole is drilled in the beam? No.
Is doing so an industry accepted practice? Absolutely not.
Is doing so allowed by code? Absolutely not.
Would a building inspector be ok with this? Absolutely not.
With this info, you can make your choices as you see fit, but I know what I would do.

Where did you learn this? Where did some of you learn to do this work?

 

[Tyberius]

I wouldn't drill through any of the beams or joists.

It appears that the ceiling is open, so there is always another way through.

It looks like there are furring strips already on the ceiling, so, I would surface mount emt conduit for the ceiling runs across the joists and put junctions at each end, then fur out to the width of the emt.

 

[teamextreme]

Where did you learn this? Where did some of you learn to do this work?

That's what I was taught when I was an electrician for 8 years, admittedly a long time ago.

 

[ishiboo]

It depends on how it was designed, I'm sure. I highly doubt drilling through to run the wire alone is against any NEC or residential building code.

If it's an engineered product, it would seem that just like an I-joist or anything else the manufacturers would provide instructions which would almost certainly indicate any holes need to be drilled in the middle area and be below a certain size and distance from the edges, and you would be required to follow those instructions. But you'd want to do that anyway.

If it's not engineered and it's from 1953, then I'm not sure what would dictate you couldn't drill through it. Common sense would say make the smallest possible hole in the center to get the wire SAFELY through. Use some thick electrical tape or braided cover to provide physical damage protection from the wire on the edge.

Be very careful when you do the actual drilling. I would drill the wood out using a hole saw to about 1" or more around the hole, then drill in the center of that with your smaller metal bit. Make sure all sawdust is nowhere to be found. It's somewhat easy to start a smoldering fire when drilling metal and wood next to each other.

 

[sberry]

Agree. It would be totally different if we were talking center span and a hole for a 3 inch drain line but that's the size of a small bolt.

 

[ishiboo]

Agree. It would be totally different if we were talking center span and a hole for a 3 inch drain line but that's the size of a small bolt.

Nah, plumbers will put a 6" cast iron waste line in a 2x8 joist without blinking an eye

 

[Speedy Petey]

Is it that closely engineered that it will structurally fail by drilling a hole? No.
Will there be any issues if a small hole is drilled in the beam? No.
Is doing so an industry accepted practice? Absolutely not.
Is doing so allowed by code? Absolutely not.
Would a building inspector be ok with this? Absolutely not.
With this info, you can make your choices as you see fit, but I know what I would do.

And you can say this with 100% certainty? Using "what you were told" in your 8 years as an electrician many years ago?
Are you now a structural engineer? Building inspector?

 

[Speedy Petey]

Agree. It would be totally different if we were talking center span and a hole for a 3 inch drain line but that's the size of a small bolt.

This!

 

[LS6 Tommy]

Sorry, I missed the part about it being from before 1953... It's against building code to drill through or cut ANY preengineered structural steel beam without engineering approval. I'm gonna say that the OP's beam wasn't preengineered...

Tommy

 

[fourjeepin]

Thanks for all of the responses. It is definitely not a pre-engineered beam. It was built on site. I am confident that drilling 3/4" holes will not impact it structurally as it has a few holes already where the 2x12s where bolted to the plate. BTW just to give you an indication of age, the bolts and nuts are square heads.

My concern and reason for posting is making sure this is safe electrically. I am leaning toward inserting some type of plastic/PVC sleeve to make sure live wires never hit the steel plate.

Some other info, wires are run through the 2x12s in many other spots where they is no steel plate sandwich. Also, the ceiling is open. It had a drop ceiling with furring strips, but it was rather rough looking and a lot of it had to come down for new plumbing and electrical to be run on the main level above it. I am leaning towards keeping it open as it is just a man cave, the ceiling aren't that high at only 8' and leaving it open makes it feel less closed in. Once I finish replacing the old non grounded wire and adding some new lights, I will paint the ceiling.

 

[teamextreme]

And you can say this with 100% certainty? Using "what you were told" in your 8 years as an electrician many years ago?
Are you now a structural engineer? Building inspector?

I am neither a building inspector nor structural engineer, leaving me by your estimation wholey unqualified to comment on such topics with only my meager past electrical experience and current electrical engineering experience. I will refrain from commenting on these topics and defer to experts such as yourself.

This!

And since you did provide comment, albiet just an agreement with a previous poster, I have to assume you hold yourself to the same high standards as you hold others and would therefore inquire, which of the 2 acceptable professions are you in the employ of, building inspector or structural engineer?

 

[Speedy Petey]

....., which of the 2 acceptable professions are you in the employ of, building inspector or structural engineer?

I hold a doctorate in both.
I am also an MD.

 

[dtcooper]

I stayed at Holiday Inn last night.. Does that count ?

 

[JamieK]

Is it an actual I-Beam? Heres what the steel engineers say about it.

http://www.steel-insdag.org/teachingmaterial/chapter28.pdf

Warning - lots of math involved!

As far as actually running the wire though the metal, its done all the time at breaker boxes. Just get one of these to fit the hole.

 

[teamextreme]

I hold a doctorate in both.
I am also an MD.

I was also going to ask if you stayed at a Holiday Inn

 

[Speedy Petey]

As far as actually running the wire though the metal, its done all the time at breaker boxes. Just get one of these to fit the hole.

Did you see the pictures?

 

[PugetDude]

You've got a flitch beam- these used to be pretty common before enginered lumber came along. It allowed the beam to be shallower and still carry the same load. If you look at the way the floor joists are notched and sitting on a nailed-on ledger board, it's even pre-joist hangar days.

It's definitely not an engineered product, so you can drill through it-and a 1/2"-3/4" " hole isn't going to cause it to sag or fail. As Ishiboo metntioned, you should use sort of bushing to keep the wire from rubbing on the plate. Millions of feet of Romex have been run through metal studs; using a snap-in plastic bushing.

Another way to look at it is to consider what the answers would have been if you posted a picture of the beam with the wires going through a 1/2" hole and asked "Is this 1/2" hole that was drilled in 1953 going to make my house fall down? Of course not- but someone here would have undoubtedly advised you to move out immediately, report the condition to the local building authorities and your insurance company, and hire a structural engineer to analyze the structural integrity of the beam...