Regarding allowable deflection of Decorative perforated Aluminum sheets 1

[Arbu]

Dear All,

I need to know allowable Deflection limit for Aluminum/steel perforated decorative sheet due to wind. Any code BS, EURO american will be okay. If any body knows the value or code reference please share.

 

[KootK]

I'd be surprised if there were such a limit. Such a system should tolerate large deflections rather well. L/60 is not unheard of in the facade world where it makes sense.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[XR250]

I have worked on some PEMB's that had L/60 for girt deflection.

 

[Arbu]

Dear KootK and XR250,

I did one manual analysis for perforated sheet and I assumed allowable deflection L/60. But now consultant is asking to support L/60 by some reference from British or Euro standard. Now I don't have any reference. sheet is 4 mm thick Aluminum perforated and purpose is decoration only.

 

[KootK]

Alas... it's become a "reference" world I'm afraid. Engineering judgment is getting more devalued by the hour, I can feel it in my bones. I blame the internet. And young people.

You can't cite a reference if none exists of course. I'd gently ask the consultant to point you to a standard referenced in the project documents that lists a deflection requirement more stringent than the one that you've applied. That, or they can shut their dang face hole. Maybe things work differently in Europe but, around here, if you go the delegated design route and don't specify the criteria for the delegated designer, you pretty much get what you get if you want to avoid an extra.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[brut3]

I realize it isn't British or Euro code based, but table 1604.3 footnote a of the International Building code give a limit of l/60 for "structural roofing and siding made of formed metal sheets". I work in the exterior cladding industry in the US and this is the deflection criteria we reference for design quite a bit.

https://codes.iccsafe.org/public/document/IBC2018/chapter-16-structural-design

 

[KootK]

Thanks for that brut3.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[Arbu]

Dear Brut3,


Thank you so much! I was looking this from last 1 month but I didn't checked in IBC. Thank you so much once again. this will be very helpful for me.