******* Electricians 6

[SteelPE]

So, I designed this multi family house over a year ago. Construction has been slow. I was last at the house 5 months ago with framing complete. Now, 5 months later I received the attached photos:

So the electrician in his infinite wisdom decided it was best to drill through one of my fancy LVL's vs bringing his conduit down at the perimeter wall of the house. Now I have been tasked with accepting the situation, or fixing the situation.

The GC has given me the position of the pipes in relation to the end of the beam. Other than checking moment and shear at this location for the reduced section, what else can I do?

Reinforcing of the beam is going to be incredibly difficult as we used CCQ style caps on the columns (meaning "adding another ply) is going to be incredibly difficult. I may be left with the option of adding a column under the hole.... but I don't want to do that unless I have to (although I would love to do it out of spite).

 

[MIStructE_IRE]

Have you checked if it’s even a problem? Doesn’t look like the end of the world to me..

 

[rowingengineer]

Do you know at what point along the beam the hole is? I would check it at this point.

 

[HouseBoy]

I vote with kipfoot.
And to add to that, it would not be necessary to place the post directly under the hole (looks like a doorway there). If you can place a post off to the side a certain distance, you might even be able to locate it so that the hole is at the point of inflection.

I don't like the idea of cutting the beam at the post either. (I assume that comment was meant to be sarcastic).

A lot of times I find that an LVL will have plenty of moment capacity and the selection is driven by deflection considerations. I would not expect this hole to be much of a factor in deflection.

As others have asked - Is it even a problem?

 

[JStructsteel]

What am I missing here, its in the top zone, looks like in one pic you have a post under it?

Most LVL manufactures allow openings. Check with them. Otherwise, check the bending for a beam depth below the hole, and call it good. You have no excess capacity in your beam? Could check the compression at the top and see if it checks.

I would use some engineering judgement and call it good.

 

[CELinOttawa]

JStructsteel: It would shock me if the manufacturer allowed this hole without any decrease in capacity. For many this would be a 100% warranty destroyed modification of their product.

Middle third of the middle third is typical. We even have one manufacturer who specifically proscribes holes drilled for lag bolt connections. [flush]

 

[XR250]

A lot of times I find that an LVL will have plenty of moment capacity and the selection is driven by deflection considerations.

My experience as well. Honestly, I can't remember the last time I even checked an LVL for strength.

 

[ChorasDen]

Follow the design equations in chapter 3.4.3.2 of the NDS that discuss stress concentration reductions for notches in beams. If this is a tension side notch (if you put a post below the notch location), then you'll need to make sure you get the correct stress concentration reduction referenced. For tension side notches, the stress concentration factor should be squared.

I know that the stress concentration factors in NDS apply only to shear, but I would suggest also adjusting design moment using the stress concentration factor.

Alternatively, depending on who the LVL manufacturer is, they often have in house engineers who can assist with local stress analysis and repair if needed for this type of damage. Have you tried reaching out to the manufacturer? The notch only looks like it affects one of the plies, so it's probably not that big of a deal either way, but may be helpful to get confirmation from the manufacturer.

 

[SteelPE]

So, I went back into my software and changed my 3-11 7/8" LVL's to 3-9 1/4" LVL's and the beam still worked.

My main issues were in relation to a concentrated load that was on the other end of this beam and the associated bearing and shear issues with this concentrated load (which is located no where near this notch). Deflection wasn't really an issue with this beam... and bending moment was only 50% of beam capacity. So based upon this information I am going to say that with the reduction in section that this beam is still sufficient.

 

[jayrod12]

That's a good call. I love giving the contractor a break, but I also hate it when no remediation is required, because it gives the illusion to the electrician that they can do whatever they want whenever they want.

 

[bones206]

I took this photo at my neighbor’s house which has been under construction for about 18 months now. The 3-ply LVL ran full length of the basement with 3 posts and 4 spans. The HVAC crew completely severed the beam in several places to pass their duct through. Just thought I’d share

 

[3DDave]

Isn't the routing of such things covered on the plan?

 

[bones206]

When they built my house, the builder didn't engage the HVAC company to design anything until well after the framing was already complete. I was on their ass the entire project, so they didn't do anything quite this atrocious to my house... but I had to constantly call them out for stuff like this every inch of the way. He still gives me the finger every time he drives past my house haha...

I kind of chuckled to myself when I saw the photo in the OP, because it's probably one of the least offensive contractor screw ups I've seen in recent weeks. It's all relative I guess, which is why I shared my photo to help cheer up SteelPE

 

[phamENG]

3DDave - in a house? Absolutely not. In a commercial building? It depends. On small/tight budget jobs it's usually just a cartoon from MEP and the field guys just make sure point A is connected to point B and who cares what's in the way. On higher budget and government jobs with more oversight the MEP plans may actually show where to put it.

But that doesn't always matter. I went out of my way to coordinate with the architect and MEP designer on a recent project adaptive reuse project, giving them very specific locations where they could route ducts and the sizes of holes they could put in existing structural members. Not that it did any good. First day on site the MEP contractor cut a giant hole (>80% depth, width about 95% of depth of joist) in a TJI web tight to the top flange and right over the support.

 

[3DDave]

I'm shocked.

Well not that shocked.