Fire-resistant joint

[pmarx]

2009 IBC

1B

R-2

Fully sprinklered per NFPA 13

1. 2 hr U.L. design pre-cast concrete plank floor bearing on 2 hr U.L. design CMU per Table 601.

2. These masonry bearing walls are also corridor walls that still require a minimum 1/2 hour rating per Table 1018.1 so the walls are not permitted to have unprotected openings.

3. The planks are installed on +/-1/8" masonite pads for erection purposes that compress leaving no more than 1/16"

gap. Reason would say that this is a "joint" but is it one that requires anything more than filling it with mortar (as the bottom course is)?

4. This gap is not for seismic or expansion requirements. Is it the intention of the code that it must be protected any more than any other mortar joint? Any formal technical opinios on this?

Thanks for your opinions.

 

[globe trekker]

pmarx,

Not sure of your question. You have a U.L. listed, 2 hr. rated celing & 2 hr. rated CMU

walls in an R-2 Occupancy, fully sprinkled. Exception # 2, from Section 1018.1, 2009

IBC, says that a fire resistant rating is not required in the corridors within a dwelling

or a sleeping unit.

Please clarify!

.

 

[pmarx]

Thanks for your reply globe trekker. I'm sorry I wasn't clearer. These corridors aren't within the dwelling units so as far as I can find, they still require a minimum 1/2 hour rating and 20 minute opening protection.

The minute gap at the top of the wall isn't installed between the wall and floor to "accomodate structural displacements caused by thermal expansion and contraction, seismic activity, wind or other loads" (from the commentary).

The question came up from the GC, not the inspector, and we had never considered it. LOL, now we are.

 

[globe trekker]

Thanks "pmarx" for the clarity! The joints would need to be sealed to match the rating

of the required rating of the corridor, ..by an approved type sealant.

Hope this helps!

.