Interpretation #8683

Original Request

Code Version: 2021
Code: BUILDING
Code Description
Chapter
Section: 110.8 and 453.25.6
Topic: Penetrations of Threshold Buildings

Question

Is it the intent of FS 553.79 (5), FBC 453.25.6, and FBC 110.8 to require a threshold inspection plan and a threshold inspector on a bonafide existing threshold building, for a 3/4" electrical conduit penetration or any other similar drilled or cut penetration to an exterior wall for a fire alarm replacement only? Are all exterior envelope penetrations to threshold buildings, no matter how big or small, required to have a threshold inspector?

Answer Published 09/07/2022 at 8:09 AM

Based on FS 553.79(5)(a), It depends if the wall being penetrated is considered part of the structural system or is a structurally load bearing component of the building. This will be determined by AHJ at permitting and either require a threshold inspection plan or not.

Commentary

There is also a declaratory statement, DS 2014-061, which addresses this. A structural alteration to a threshold building must be evaluated on a case-by-case basis by the AHJ. Though a 3/4" hole in a wall might not be considered much of an alteration, drilling through a slab of post-tensioned construction, whether vertical or horizontal, could damage a PT cable, have impacts on fire resistance or pose other implications.