2006 IBC, Table 601, footnote d question.

[khsmith55]

2006 IBC, Table 601, footnote d question. Given a Type VA, NFPA 13 sprinkler (sprinkler needed for area increase so can not substitute for one-hour construction), 3 story building with underground (basement) parking. First floor commercial, second and third floor(s) apartments. In Table 601 heavy timber can substitute for one-hour construction (footnote d) at the roof construction ONLY and not at floor/ceiling construction. Any reasoning behind this or am I missing something. It appears any wood beams in the second and third floor framing will either have to be protected by the membrane of the one-hour floor/ceiling system (i.e. buried beam) or be “wrapped” to provide one-hour fire protection (i.e. joists bearing on beam). It would be of great help if I could use 5 1/8" x 12" exposed GL’s, any help or guidance would be appreciated. Thanks in advance.

 

[cda]

My take is heavy timber is not supposed to be covered up

 

[north star]

+ $ + $ +

khsmith55,

Traditional Heavy Timber framing has a much longer "burn thru" time

than the newer engineered beams.

IMO, I would recommend that you contact the BO and the FCO in

the jurisdiction of your project to get their input.......Most likely,

they will require wrapping or other approved methods, to protect

any engineered wood you desire to install.

FWIW, ...most engineered wood used for structural loads can

support the loads imposed on them, but they stink at providing

adequate "burn thru" times [ EX: engineered I-joists ].

+ $ + $ +

 

[kilitact]

Footnote C allows HT has a substitute for 1-hour

 

[khsmith55]

Kilitact; Confused...read footnote c and it appears it has no bearing? I'm using the 2006 IBC. Footnote d allows for HT as a substitute for 1-hour, BUT, at the roof only.

 

[mtlogcabin]

If you want exposed timbers in a VA building you need to be looking at 721.6.3 for the fire-resistance rating of timber beams and columns.

721.6.3.3 will require the fasteners to be protected

 

[khsmith55]

Thanks Mtlogcabin! This section will work great for me on this project and on future projects now that I'm aware of the section.

 

[cda]

Does the heavy timber have to be exposed?