3/4" Plywood as finished surface in Type IIb construction

[mwskopf]

Morning all
I am working on a small equipment rental shop with an M showroom and S-1 shop/storage area.
2018 IBC
I'd like to indicate a small mechanical deck above restrooms with metal joist framing @ 16" o.c. with 3/4" plywood as the finished floor surface if code allows. I'm looking at section 804.2 (kicked over from 603.1 item 10) which then refers over to section 804.4.2 for areas in "enclosures for stairways and ramps, exit passageways, corridors and rooms or spaces not separated from corridors....". My mechanical deck is not any of those things. Does that mean that the floor does not have to be "Fire rated Classified" since I am not in those areas?
Thanks

 

[BN4537]

I think it complies with the exception of 804.1 as a resilient floor covering materials that are not composed of fibers. Obviously wood is made of fibers, but I think they meant carpet.

If not, it looks like your plywood only has to meet the "pill test" or ASTM D2859. I don't think 804.4.2 applies for the reasons you described..

 

[Tim Mailloux]

Morning all
I am working on a small equipment rental shop with an M showroom and S-1 shop/storage area.
2018 IBC
I'd like to indicate a small mechanical deck above restrooms with metal joist framing @ 16" o.c. with 3/4" plywood as the finished floor surface if code allows. I'm looking at section 804.2 (kicked over from 603.1 item 10) which then refers over to section 804.4.2 for areas in "enclosures for stairways and ramps, exit passageways, corridors and rooms or spaces not separated from corridors....". My mechanical deck is not any of those things. Does that mean that the floor does not have to be "Fire rated Classified" since I am not in those areas?
Thanks

The floor decking needs to be non-combustible in type IIB construction. Refer to 603 for instances where combustible construction is allowed in type II construction. Looking at the list of exceptions I don't see anything that helps you at first glance. In type II construction I have typically designed these types of structures with cold form joists and either a thin metal crinkle deck with a plywood sub-floor on top, or 3/4" thick structural panel concrete sub-flooring by USG or equal..

 

[Tim Mailloux]

I think it complies with the exception of 804.1 as a resilient floor covering materials that are not composed of fibers. Obviously wood is made of fibers, but I think they meant carpet.

If not, it looks like your plywood only has to meet the "pill test" or ASTM D2859. I don't think 804.4.2 applies for the reasons you described..

but the plywood is also part of the structural assemble of that floor, so I don't think classifying it as a finish is a free pass.

 

[mwskopf]

One of the main reasons that I brought it up was that a previous architect on one of the client's other buildings called out the plywood, so I got to thinking about it....
Anyway,
Is there any reason that a shallow metal deck could not be used for the floor purpose to set the equipment on? One with narrow ribs to avoid a tripping hazard. Otherwise, I'll probably spec a "Structocrete" cement floor board or mag oxide panel.
Thanks guys

 

[steveray]

Like Tim said...structural floor no...floor finish, yes...Deck with plywood over it...Unless you find a gimmie in platforms....

 

[mwskopf]

Thanks all,
Could a person use the narrow rib roof deck (see attached) by itself as opposed to the cementitious underlayment mentioned before? Seems like a furnace or water heater would sit fine on it and not be unsafe to walk on.

 

[Paul Sweet]

If the building is Type II (non-combustible) construction I'd use 9/16" steel deck (typically used as a form for concrete over bar joists) with 3/4" T&G plywood on top.

 

[mwskopf]

I would be good with that too and it would probably more economical than the spendy Structocrete.