# Drilling through engineered joists



## 99cents (Aug 20, 2012)

I opened up a wall on a renovation job and the previous electrician drilled two holes through the top of an engineered joist below a bearing wall. If I did that my GC'S would castrate me.


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## elecpatsfan (Oct 1, 2010)

Funny thing is I'm sure everything is perfectly fine.


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## chewy (May 9, 2010)

Yep, I asked the lead carp the other day if it was cool to drill 4x 38mm holes for our looms to go in and he said go ahead. I don't do much work of the resi type and the GC threw a **** fit. They said they weren't battening the ceiling in that part of the remodel of the school so I don't know how they thought my cables were going to get inside there.


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## mbednarik (Oct 10, 2011)

I was told round holes only and no more than 1/3 of the height of the joist.


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## jefft110 (Jul 7, 2010)

They use to send a pamphlet with those beams showing where and what size hole you can drill.


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## macmikeman (Jan 23, 2007)

Cut a notch in the plywood covering the top side of the joist. Run your cable thru the notch, and put a nail plate covering over that. No hole drilled thru engineered joist, and no one can sue you over it. Guess who does this all the time when having to cross a glue lam beam? Thats right, your ol Uncle Mikey does it like that.....


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## Deep Cover (Dec 8, 2012)

I remember those spec sheets, I thought they basically equated to center third, center third.


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## butcher733 (Aug 4, 2012)

Most of the engineered joists I have dealt with have ko's in them that you can bust out with a hammer.


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## Deep Cover (Dec 8, 2012)

butcher733 said:


> Most of the engineered joists I have dealt with have ko's in them that you can bust out with a hammer.


Those are completely different than engineered beams.


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## drumnut08 (Sep 23, 2012)

99cents said:


> I opened up a wall on a renovation job and the previous electrician drilled two holes through the top of an engineered joist below a bearing wall. If I did that my GC'S would castrate me.


Whether they're I - joists , or glue lam's , if you're in the center and you're not boring a giant hole , there will be no issues . Stay out of the top and bottom third to avoid getting yelled at , lol .


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## Wingman2002 (Jan 2, 2011)

I know where we have been told we can but we will choose another route when possible. It seems like our inspection request a engineers approval for the least little thing .... Hole!!!


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## electricmanscott (Feb 11, 2010)

elecpatsfan said:


> Funny thing is I'm sure everything is perfectly fine.


Yup. Look at the houses we see around here. 200+ year old houses built with pieces of trees that have stood through countless blizzards, hurricanes etc. Engineers and carpenters get a woody way over building this stuff. Any engineered beam is a gazillion times stronger than standard dimensional lumber that nobody thinks twice about drilling through.


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## BBQ (Nov 16, 2010)

elecpatsfan said:


> Funny thing is I'm sure everything is perfectly fine.


I am not.

If this was a wood 'I-beam' drilling through the top or bottom cord really weakens it a lot. 










Just because it did not cause a problem yet does not mean it would not.


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## BBQ (Nov 16, 2010)

electricmanscott said:


> Any engineered beam is a gazillion times stronger than standard dimensional lumber that nobody thinks twice about drilling through.


It stronger is until you screw up the load carrying sections.


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## electricmanscott (Feb 11, 2010)

BBQ said:


> It stronger is until you screw up the load carrying sections.


You assume that it is screwed up by two sentences on the internet. Such a nervous Nellie. :laughing:

I really doubt based on the OPs description, that there is, or will ever be a problem. Working primarily in resi remodeling for 25 years and seeing what, or what isn't holding up houses I can say that with authority. In fact, I was pointing and shaking my finger at the screen as I typed it. :thumbup1:


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## wildleg (Apr 12, 2009)

engineered wood - trusses, lam beams, I joists, or whatever - requires that the manufacturer's instructions for that product be followed, whatever it is. If you hit a job and it has engineered lumber, get the manufacturer name form the product or from the super, download the instructions, read them, and follow them. It's that simple.


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## BBQ (Nov 16, 2010)

electricmanscott said:


> You assume that it is screwed up by two sentences on the internet.


And yet you are telling us it is not. Just as dumb. :thumbsup:



> I can say that with authority. In fact, I was pointing and shaking my finger at the screen as I typed it. :thumbup1:


:thumbsup:


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## toolaholic (Aug 13, 2010)

mbednarik said:


> i was told round holes only and no more than 1/3 of the height of the joist.


thats only dimensional lumber !


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## chicken steve (Mar 22, 2011)

I think i've roughed every possible building method to this point in my carear

and i could care less if they consider recycled dogsh*t to do it

the mechanicals should ALWAYS be an intergral part of the plan

I've had job meetings where the hvac, plumber and i had to stand our ground and state our critical paths don't change, the _responsibility_ is on the manufacturer and or it's engineer to provide what would normally be inclusive within the structure.

Anything short of this is akin to engineering a car w/o a motor 


just my usual lovely opinion.....:thumbsup:

~CS~


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## christrician (Aug 6, 2011)

chicken steve said:


> I think i've roughed every possible building method to this point in my carear
> 
> and i could care less if they consider recycled dogsh*t to do it
> 
> ...


No one ever thanks chicken Steve for his comments... WTh?


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## B4T (Feb 10, 2009)

This is a typical spec sheet from the manufacture that tells you where to make holes.. http://www.gp.com/build/DocumentViewer.aspx?repository=BP&elementid=11562


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## 99cents (Aug 20, 2012)

BBQ said:


> I am not.
> 
> If this was a wood 'I-beam' drilling through the top or bottom cord really weakens it a lot.
> 
> ...


Yes, these holes were drilled through the top cord.


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## danickstr (Mar 21, 2010)

drilling through the plywood on top seems like it may compromise the structural integrity and could get you a nail from a flooring installer as well?


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## macmikeman (Jan 23, 2007)

danickstr said:


> drilling through the plywood on top seems like it may compromise the structural integrity and could get you a nail from a flooring installer as well?


Did you miss the part about the nail plates?


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## electricmalone (Feb 21, 2013)

macmikeman said:


> Did you miss the part about the nail plates?


The funnything with nail plates is the flooring guy / sheetrockers will pull them off so they don't bulge their work...
Notching the top or bottom of any wood f's it up. This Old House has some good segments on the proper way to cut through joists. Glue / screw plywood sandwich both sides of joist then drill freely. Holds things together nice. My apprentice won't think twice boring a 4 1/2" hole through a 2x10 versalam. My boss thinks its fine and doesnt understand when the frame fails inspection, we have to pay the framer to go back and make it right...:blink:


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## chewy (May 9, 2010)

99cents said:


> Yes, these holes were drilled through the top cord.


Eeeew, are you guys that hard up for timber you use that ****?


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## butcher733 (Aug 4, 2012)

BBQ said:


> I am not.
> 
> If this was a wood 'I-beam' drilling through the top or bottom cord really weakens it a lot.
> 
> ...


That is what I was speaking of having the ko's.


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## eds (Mar 21, 2009)

Found out this new code requirement that is upcoming in the IRC, apparently any unfinished areas with open floor trusses or I-joist need to be sheetrocked. From what I was told, a fire weakens the glue on I-joist and the joist literally roll over and loose all strength. Open floor trusses the gang plates heat up in a fire and pop out.


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## FlatRateGator (Feb 13, 2013)

christrician said:


> No one ever thanks chicken Steve for his comments... WTh?


Because so very few of his posts mean anything.


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## chewy (May 9, 2010)

FlatRateGator said:


> Because so very few of his posts mean anything.


No not if your an illiterate philistine who just crawled out from under a rock.


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## LARMGUY (Aug 22, 2010)

FlatRateGator said:


> Because so very few of his posts mean anything.


You must first have the cognitive ability to discern his posts then the comparative faculties to relate his style to all of his previous posts and the other members posts in kind remembering he is, and always will be, diagonally parked in a parallel universe.

:blink:


:laughing:


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## Magnettica (Jan 23, 2007)

Deep Cover said:


> I remember those spec sheets, I thought they basically equated to center third, center third.


That's the way I was taught.


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## Magnettica (Jan 23, 2007)

drumnut08 said:


> Whether they're I - joists , or glue lam's , if you're in the center and you're not boring a giant hole , there will be no issues . Stay out of the top and bottom third to avoid getting yelled at , lol .


Yelled at? Brother, a bad screw up could cost thousands to repair.


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## FlatRateGator (Feb 13, 2013)

chewy said:


> No not if your an illiterate philistine who just crawled out from under a rock.


There is a difference between being intellectual and regurgitating a thesaurus on an electrician forum.

Normal Electrician: "Flip the breaker."

Steve: "Actuate the handle protruding from the anterior plane of the overcurrent apparatus."

There is no reason for it except to try and impress us lowly philistines.:no:


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## macmikeman (Jan 23, 2007)

FlatRateGator said:


> There is a difference between being intellectual and regurgitating a thesaurus on an electrician forum.
> 
> Normal Electrician: "Flip the breaker."
> 
> ...


I was doing some of that bout an hour ago and the missus walked in on me and caught it.....


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## chewy (May 9, 2010)

FlatRateGator said:


> There is a difference between being intellectual and regurgitating a thesaurus on an electrician forum.
> 
> Normal Electrician: "Flip the breaker."
> 
> ...


You could see it as an opportunity to increase your vocabulary.


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