Design criteria

[Sifu]

Continually see engineers using and including the IRC design criteria in the structural calculations for non-IRC projects. I would say the majority of the time. They cite the code, then include the table. Makes no sense to me, and curious as to why. Is it my ignorance or theirs? Example from today:

 

[mtlogcabin]

Except for the class "D" seismic zones in the IRC aren't they the same for both codes?

 

[RLGA]

What is the IBC equivalent? I think they are using the format from the IRC since the IBC has no equivalent format. However, the criteria entered should be based on the IBC, which can be a bit tricky since some of the criteria required, as per the table, do not correlate with the IBC.

 

[Yikes]

It’s a copy/paste thing from previous projects.

I once spec’d a pre-engineered aluminum trellis for a courtyard in a multifamily housing project. Sent the calcs into the city, the plan checker bounced it back saying calcs were based on the IRC. Went back to the the company to get IBC calcs and they said (1) it couldn’t be changed, the structural engineer died last year, (2) no other commercial project got flagged for this.

 

[arwat23]

I agree with Yikes. Definitely copy/paste. I deal with this constantly, but from the other side of the desk from you.

I'm responsible for our firm's CAD / BIM standards and setting up the project templates for our office. My coworkers here are... well, imo, they're a little lazy. They want me to add basically every typical note we could use on a project so they can sort through and delete the ones they don't need when it comes time to set up the CDs for a project. For example, there are three notes just discussing the different exception for door push plates, so the designer needs to make sure they remove the notes that don't apply (which, of course, they don't do). This has caused a lot of headaches during plan check and construction, but the powers that be like the setup so I leave it be.

Just recently, my coworker submitted some drawings for a residential project that referenced both IBC and IRC (which we can't do in CA - it has to be one or the other). Only reason this happened was because they copied a bunch of notes from a previous project and just assumed they were good.

I've seen this happen on basically every project I've been apart of in some way. Sometimes it's us, sometimes its the engineers, I've even had this problem with AHJs on occasion.

 

[Sifu]

I agree with Yikes. Definitely copy/paste. I deal with this constantly, but from the other side of the desk from you.

I'm responsible for our firm's CAD / BIM standards and setting up the project templates for our office. My coworkers here are... well, imo, they're a little lazy. They want me to add basically every typical note we could use on a project so they can sort through and delete the ones they don't need when it comes time to set up the CDs for a project. For example, there are three notes just discussing the different exception for door push plates, so the designer needs to make sure they remove the notes that don't apply (which, of course, they don't do). This has caused a lot of headaches during plan check and construction, but the powers that be like the setup so I leave it be.

Just recently, my coworker submitted some drawings for a residential project that referenced both IBC and IRC (which we can't do in CA - it has to be one or the other). Only reason this happened was because they copied a bunch of notes from a previous project and just assumed they were good.

I've seen this happen on basically every project I've been apart of in some way. Sometimes it's us, sometimes its the engineers, I've even had this problem with AHJs on occasion.

My thinking is it's laziness. It doesn't help that the criteria are different, and with changing terminology. And yes, MANY times I have had AHJ's answer the design criteria question with the IRC table. I have questioned a few engineers specifically about this and their response was that it came from the building department. I do not doubt that. Most of the time they do have the correct data and references to ATC, IBC, ASCE7 buried in the actual calcs. Just an anomaly I figured I would ask about today.