In the process of renovating an existing building, type IIB structure, under the 2015 IBC. The existing space has a slab-on-grade floor change of 20". For design & programming purposes, the renovation plan is extending the higher elevation (via the use of a platform as described within 410.4) by roughly 1,000 sf (less than 1/3 of the total build-out space) and will not have any storage beneath the platform. To access the higher floor elevation, the plan includes (1) ramp and (1) stair. Given that the raised platform will be constructed of fire retardant treated wood, I'm wondering if it's also acceptable to construct the stairs & ramps in this same fashion. However, I have been unable to find any code verbiage to allow these (stairs & ramps) to be constructed of anything but 'non-combustible materials' per type IIB Construction requirements (reference 1011.7 & 1012.7).
In my Opinion - Given that +/- 1,000 sf of the platform is of combustible construction, it's confusing to require the stairs & ramps providing access to this floor elevation to be steel - given the 'small fire risk' posed by the platform construction. The steel does not seem to provide any added life safety benefit in relation to the structure it's serving - and will end up increasing the renovation costs. Is there something I'm missing or misunderstanding?
If anyone could provide insight to this it would be very much appreciated.
In my Opinion - Given that +/- 1,000 sf of the platform is of combustible construction, it's confusing to require the stairs & ramps providing access to this floor elevation to be steel - given the 'small fire risk' posed by the platform construction. The steel does not seem to provide any added life safety benefit in relation to the structure it's serving - and will end up increasing the renovation costs. Is there something I'm missing or misunderstanding?
If anyone could provide insight to this it would be very much appreciated.