Vertical Deflection Limits for Adhered Veneer

[jdgengineer]

What deflection limits do you all use for vertical deflection due to dead load + roof live load for adhered veneer attached to a wood frame structure? ACI 530 specifies L/600 for anchored veneer but I do not see a limit started for adhered veneer. I don't see it specified in the IBC either, but perhaps I am missing it. We typically use L/600 but want to make sure that is not too conservative.

 

[XR250]

I use L/600 for most things residential as it does not cost much more to upsize a beam.
For instance, a 14" LVL is almost twice as stiff as an 11 7/8" but only costs 17% more.

 

[jdgengineer]

We do as well, but in this instance it is a header supporting roof framing that may need to be steel to hit L/600.

 

[phamENG]

If you want to sail that close to the wind, your best bet is to call the manufacturer and find out what they recommend - and get it in writing, along with the required installation instructions and backing prep. Make sure you spell it all out just as they direct, and if it cracks to pieces at least you can say the manufacturer said to do it that way.

Don't suppose it's a sliding door? If it is, you may need to do better than L/600 anyway.

 

[jdgengineer]

Thanks guys, I just wanted to see if there was something in the code that suggested the deflection limits for adhered veneer. It sounds like we all use L/600 although I don't see this specifically required for thin veneer, it makes sense and we'll keep it.

It's not a sliding door, just a large window. This is also a single-family residence (I should have started with that). For sliding doors we design for the lesser of: 1/8" max live load, L/720 or 1/4" max total load, and additionally L/2000 or 1/8" max creep loading for wood headers. This covers the standard sliding door requirements we have seen from Nanawall, La Cantina, Fleetwood, Marvin, and Centor.

 

[phamENG]

Nice. Sounds like you've got it covered.