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Deflection criteria

Deflection criteria

Deflection criteria

Does anyone know of a one-stop reference for deflection criteria for various conditions/materials(i.e. L/360 for floors covered with gypsum drywall, etc.)?

RE: Deflection criteria

There was a good article in the Engineering Journal (AISC - First Quarter, 1993) that provided wind serviceability limit state recommendations (like L/400, etc.) for various types of building frames and exterior cladding.  Other than that, I'm not aware of anything that covers as much as this did.

RE: Deflection criteria

Thanks. I'm more interested in limiting deflections for live loading. (i.e. floors, countertops so that tile doesn't crack, etc.) I generally use L/480, but I was wondering if there might be a reference that summarizes industry standards. The only way I know of now is to use the standard of whatever material you're working with (gypsum association for deflection creiteria if you're using a dywall ceiling, etc.)

RE: Deflection criteria

I find the AISC Design Guide 3 "Serviceability Design Considerations for Low-Rise Buildings" helpful in this regard. It covers allowable deformations for vertical and lateral loads, and considering a variety of non-structural systems that may be affected by those deformations. I would consider L/480 to be rather conservative for most applications.

RE: Deflection criteria

Thanks. I'll check it out. I was more interested in knowing if anyone has run across a "one-stop" reference (steel, wood, concrete, gypsum wall board tile, etc.). I haven't seen one. I've found that there are often complaints from homeowners is high-end homes when using L/360 for floor joists, especially for longer spans when using TJI's. The floor is too "bouncy". L/480 seems to work well for this case.

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