Fire protection on trusses?

[twoply]

Commercial building.
VB
Business use.

They are remodeling the interior and gutting all non-load bearing walls. As they demo, there are gaps in the ceiling drywall where the walls butt up to it.

They have no plans to patch these holes before installing a suspended ceiling under them.

"Dont look for what you think is in the code, look for what is there."

I always have been under the impression that the bottom chord of the truss needs to be covered in a fire rated skin. (drywall)

Now I'm stumbling around trying to find a related code section to refer to. Have I been wrong all this time? I cant find the code section.

Can anyone help?

Thanks in advance.

 

[Builder Bob]

unfortunately, the type of construction VB does not require any fire rating. However, the air movement between the attic space and the tenant will not be great - they are not going to meet the energy code nor will they meet the requirements of 711.3.

The biggest thing is that the ACT ceiling cannot have insulation installed over it as it does not act as an air barrier thus does not meet energy code requirements.

Just out of curiosity, did you hear this from a fire fighter or fire marshal?

 

[JBI]

Also the adopted code year editions and state or local amendments can dramatically change answers to even somewhat simple questions.
Letting the group know where the project is located is helpful, letting the group know which year edition even more so.

 

[steveray]

The bottom chord requires bracing which could be sheathing or gyp typically, but also "X" on center bracing....

 

[ADAguy]

good question and responses to an often overlooked issue.

 

[RLGA]

A fire-resistance-rated ceiling is not required for Type VB construction. If the building is not located in Climate Zone 2B, then an air barrier is required. If the space within the trusses is a vented attic, then you obviously would not have a compliant air barrier. If the trusses are low-sloped with no vented spaces, and the roof membrane is a single ply system, then the air barrier requirement may be met using the roof membrane (there may be some detailing issues, such as at parapets).