NFPA - fire rating height limit

[rbcameron1]

Was there something in a fire code somewhere that stated in a 1 story building if you are above 25'-0" you don't need a fire rated assembly. For instance, if I had a really tall wall with made of a 2hr assembly but it doesn't hit the bottom of the deck until 26'-8", just curious how a fire is going to reach that height. The question arose because it didn't seal up with fireproofing material. It was just gyp board straight to deck (w/ sealant).

 

[rbcameron1]

I think I found my answer: IBC 2009 - Table 601 TYPE IIB - exception B. 20'-0" and up doesn't require fire proofing.

 

[cda]

2009 ibc:::

Note b applies to the construction of the roof and related secondary members in all types of construction. It allows these elements not to be of protected construction when all parts of the roof construction are more than 20 feet (6096 mm) above any floor below. This only applies to the secondary members of the structure and not to primary structural frame located within the roof or at this roof level [see Figure 601 (1)]. This alternative is applicable for all occupancy classifications except Groups F-1, H, M and S-1. Figure 601(2) shows an example where a mezzanine reduces the clearance to the roof to less than 20 feet (6096 mm) for a portion of the total roof. Designs similar to Figure 601(2) do not comply with note b, and elimination of fire-resistance is not allowed for any of the roof.

 

[Examiner]

It took me a minute but I hope he understands it's the roof that can avoid fireproofing not the wall. The wall still has to go up to the roof deck.