Structural stability

[Inspector 102]

When applying the 2006 IBC, Section 705.2, how does one determine the structural integrity of the wall assembly. Design Professiona has submitted a wall assembly per UL U419 giving a total wall thcikness of 6 sheets of 1/2" wallboard, RC channels and 3 5/8" metal studs to construct a 3-hour fire wall. The roof assembly continues over the fire wall but it appears the wall meets the section for compliance. This wall is to maintain the fire area less than 12,000 SF for fire area since an automatic fire protection system is not a reasonable options based on location. Is it the intent that the roof should collapse on either side of the wall without impacting the wall, or is the wall supposed to maintain any loads against it under fire load conditions. If the steel bends down on either side of the wall, the wall needs to remain standing correct. Does the UL design tak into any consideration the structural integrity or stability?

 

[steveray]

I believe a fire barrier is all that is needed for different fire areas.....so the structural independence goes away.....

 

[Builder Bob]

The concern that you are expressing is for a true fire wall which should allow the construction to collapse on one side without affecting the construction on the other side of the fire wall.The most often abused section of the code when people are using preengineered buildings with structural beams and purlins running across the non-load bearing fire wall.

The UL guide usually has some language in the fine print about wall heights etc. when using a design for construction.

 

[peach]

702.1 - Fire wall needs to continue from the foundation to/through the roof with sufficient structural stability to allow collapse... (blah, blah).. if the wall is being built to contain fire to a fire area, it can be done with a fire barrier (different than a fire wall). You need to drill down into the UL listing to read what the fire conditions are.. plan reviewer job, not inspector, so I personally haven't looked that closely in years.. sorry

 

[crengr01]

This is a question I have been pondering for several years (and fortunately have not been forced to answer yet). Living in a seismically active area where wall-to-roof connections need to be quite robust, how can you have a connection that allows the roof on either side of a wall/partition to collapse without affecting the wall?

 

[brudgers]

Why are you in section 705.2? Is this based upon the architects actual code analysis?