2012 IBC Wind Deflection Limits

[ajcarl]

I am designing to 2012 IBC for the first time (solar carport) and notice that the wind deflection limits in table 1604.3 remain unchanged.
But wind has changed to a strength level load so these deflection limits are now more restrictive.
I think this is a mistake and instead of "W" they should say 0.6W

Footnote f was changed by multiplying the previous 0.7 x 0.6 to equal 0.42 (but I would have left this alone and made the change I mention above).

What do people here think?

 

[briancpotter]

As you said, the limits aren't actually more restrictive, the scaling factor is just located in the footnotes instead of in the table heading.

I don't have any particular qualms about this. I disagree that they should have ignored the footnote, since having one scaling factor in the table heading and another in the footer is a recipe for confusion.

Brian C Potter, PE

http://simplesupports.wordpress.com

 

[ajcarl]

That is fine for component and caldding but it appears they have not addressed the change to MWFRS which I why I said to leave footnote f and say 0.6W in column heading so both component and cladding and MWFRS forces are scaled down to ASD level.

 

[azcats]

In my mind, the 'W' is wind in the general sense...not specifically telling you wind load. They even tacitly acknowledge in the footnote that the wind load should be multiplied by 0.6 to get to service loads.

I would use the service loads.

 

[UcfSE]

Are you checking deflections with MWFRS?

 

[briancpotter]

UcfSE, that was my thought. I couldn't think of a situation where you'd check deflections using MWFRS loads.

Brian C Potter, PE

http://simplesupports.wordpress.com

 

[ajcarl]

the case is parking canopy with cantilevered column supporting beam to make a "T" structure. the beam is designed using MWFRS wind loads