What if a roof member is also part of the primary structural frame of the building, which is governed by a separate row of IBC Table 601?


Footnote “c” of IBC Table 601 permits heavy timber for roof construction in all construction types except Type I-A when the required fire resistance is one hour or less. But what if a roof member is also part of the primary structural frame of the building, which is governed by a separate row of Table 601? A code change was approved in the last ICC code change cycle, G102-18, which makes it clear that footnote “c” applies even if the roof member is a part of the primary structural frame. The footnote in the 2021 IBC will read “In all occupancies, heavy timber complying with Section 2304.11 shall be allowed for roof construction, including primary structural frame members, where a 1-hour or less fire-resistance rating is required.”