wood mechanical platform in IIB construction

[steveray]

Knock on wood...You are punny!

How deep is typical B deck? I would use 803.13 up to 1.75"

803.13.1 Direct attachment and furred construction.
Where walls and ceilings are required by any provision in
this code to be of fire-resistance-rated or noncombustible
construction, the interior finish material shall be applied
directly against such construction or to furring strips not
exceeding 13/4 inches (44 mm), applied directly against
such surfaces.

 

[ADAguy]

Is this open to the weather or within a space?

 

[Sifu]

Similar situation, but not a floor. Plywood or OSB specified on the outer surface of a lid above a paint room, top of the room is an L527 assembly framed with steel joists. Building is type IIB. The space over the lid is not used for storage and has no access and would not meet the definition of a platform.. It would be a stretch for allowance as a floor finish or covering since it is not a floor. But even so it would need to meet the requirements of 804. But 804.1 exempts "traditional" floor coverings...such as wood. Problem is, this is an existing paint room in a huge, zillion dollar facility, being enlarged, and this was allowed previously. Are we sure this isn't a valid path? Or is it moot because it is not a "floor"...an undefined term but according to Webster's the closest definition is "the surface of a structure on which one travels?"

 

[Sifu]

As a follow up, 805.1.1 initially shows promise at addressing this, but still doesn't really address an exposed, combustible plywood or OSB (normally a sub-floor) but in this case it is exposed and not a floor.