Garage Portal 2

[Supun93]

Recently i did a garage design, where i gave a strong wall for the garage wall because of garage opening. Later client came back to me telling that is is over engineered and asking me to change it.
The client had his Engineer modify from strong walls to replacing them with Hdu hold downs shown in attached picture. MSTC28 (x2) making the king stud and top plate connections. at the bottom strong walls were replaced at the bottom with Hdu. The inspector allowed this change with their RFI from their Engineer. Is this something we can do, how are we going to provide a calculation for this. Aspect Ratio is not in the acceptable limit as per the codes.

 

[ctopher]

Why do double work? Have the client's engineer supply the calculation.

 

[ChorasDen]

APA has a white paper on design capacity of garage portal frames, including required minimum aspect ratio of wall segments and connections, based upon testing. I don't know the document number offhand, but I would expect it easy to find on their website. One thing to note is that it is a tested assembly, and as such, limited to maximum wall heights and minimum header sizes. The assembly connection between the wall segment and header needs to meet their criteria, I don't see that shown appropriately in the detail you included above.

 

[Supun93]

Yes exactly. I gave them a strong wall as the design. But they refused and told me it is an over design. They propose this method. I looked through APA portal frames. Does not quite match with it.

 

[phamENG]

They propose this method.

No, they didn't propose it - they just did it.

I'd be informing the other engineer that they now own the liability on the project, and informing the the client that I'm contacting the AHJ and informing them that what was built is not my design, and that I am no longer the engineer of record and that any document with my seal should be considered null and void. Not sure about yours, but under my contract terms I own all of the documents with my seal on them - including the approved permit drawings on site. I'd collect those, as well. But I also have no patience for people who pull this kind of stuff. Don't want to build what I designed? That's fine. But don't expect me to go along with it.

 

[Supun93]

Thank you. What should i do? They compan i work for request me a letter to state that this design is ok. and, client is telling that I overdesigned by using a strong wall.

 

[phamENG]

What should i do?

Depends. Did you review your calculations and confirm that a site constructed portal frame is not adequate? If no, then do that - but have a discussion with your boss about how much time he/she wants you to spend on it - and see where you land after sharpening your pencil a bit.

If you did, and there's no way that it works, then put it back on the contractor or whoever decided this was the way to go. If they can provide you with detailed calculations proving that it works and that the construction is code compliant (and consistent - if you're basing your design on the NDS/SDPWS, IRC details don't necessarily work). Then pick apart whatever they give you. If it's good, it's good - hopefully you learned something. If not, dip it red ink and send it back proving them wrong.

Now this is what I think you should do. As for what you will do...depends on how you rank your commitment to ethical practice and job security, and how much your boss cares about practicing ethically.