Ceiling fire rating.

[Squid]

So I'm taking a stab at a retail shop, for myself.

Dabbled in construction on residential stuff for five years but never spent much time in the ICC book. Just hired people smarter than me and learned that way.

Code enforcement in this municipality refuses to answer anything, wasn't unknown going in. Won't even answer 1 or 2 hrs fire rating.

It's a four story brick building. Top three stories are office space, neighbor on the first floor is a restaurant.

At this point I believe walls need to be 1 hr. Shared first floor walls have 5/8 or two layers of 1/2" to give the one hour.

Exterior walls have 1/2" with the brick which gives at least 2.5hrs... 2 hrs for the brick if its not solid and iirc 4 hrs if it is.

The ceiling though.. I'm having a hard time with. Was going to leave open, but it's kinda messy. There's a 20 year old drop ceiling I want to take out.

Figured dry wall... which be fine but it's not just going over joists, there's support beams and such that would look horrendous with all the boxing. Even open probably be hideous.

Which unfortunately leads me back to drop ceiling which I don't like, but could go black color for it.

So... Is the ceiling of retail between office one hr? Or exempt?

If retail is code M and office is code B, does Table 508.4 say I'm exempt from needing a fire barrier? No sprinkler in the building.

 

[Squid]

and I think I read somewhere this applies if you're < 10% of the buildings space, which I am. 5%/6%.

 

[Yikes]

There are multiple response that a floor-ceiling assembly may need to be fire-rated and you need to search each reason, and also hunt for possible code exceptions that may help you.
Fire ratings for walls and floors may be due to:

• Type of construction
• Separation of different types of occupancy
• Location relative to a property line or adjacent building
• Separation of areas to gain greater allowable overall building size (commonly done in "podium" construction)
• Separation of areas for purposes of smoke or fire containment
• Shaft separations, etc.

First you have to get a little more specific in your situation:
- what was the applicable code (name of code and year) for the building at time of original construction?
- what where the approved occupancies for each floor the building at time of original construction? Have they changed since then? Has anything been "bootlegged", or does a record exist at the building department for existing conditions?
- What is the construction type that was listed on the certificate of occupancy?
- Is the building considered historic, potentially historic, or located in a district that is considered historic?
- Are you proposing a remodel or an alteration, or change in use/occupancy? Or are you just wanting to know if the building already complies as-is with no changes?

 

[Squid]

There are multiple response that a floor-ceiling assembly may need to be fire-rated and you need to search each reason, and also hunt for possible code exceptions that may help you.
Fire ratings for walls and floors may be due to:

• Type of construction
• Separation of different types of occupancy
• Location relative to a property line or adjacent building
• Separation of areas to gain greater allowable overall building size (commonly done in "podium" construction)
• Separation of areas for purposes of smoke or fire containment
• Shaft separations, etc.

First you have to get a little more specific in your situation:
- what was the applicable code (name of code and year) for the building at time of original construction?
- what where the approved occupancies for each floor the building at time of original construction? Have they changed since then? Has anything been "bootlegged", or does a record exist at the building department for existing conditions?
- What is the construction type that was listed on the certificate of occupancy?
- Is the building considered historic, potentially historic, or located in a district that is considered historic?
- Are you proposing a remodel or an alteration, or change in use/occupancy? Or are you just wanting to know if the building already complies as-is with no changes?

Building was built 1900. I'm guessing the pre-dates modern code systems.

Not sure at construction. Currently; floor 2-4 are Office Building. Part of floor one is Restaurant and the portion in question is Multi-Use Office.

Guessing ordinary type III based on brick floors and wooden floor assemblies.

No.

Remodel with change in use/occupancy. Remodel is basic, not gutting. New floors, new paint, couple walls for the small offices removed and a small storage room added. And the ceiling in question... Grandfathering was brought up when I talked to a code enforcement officer in another municipality (every single one I've dealt with has no problems responding to questions, but of course the one I ended up in won't), though I know they love to fight you on that and I'm not 100% how that works if it's still grandfathered if I replace the existing white drop ceiling with a black one.

 

[Squid]

Records from 1980 show floors 2-4 office. First floor has store and office boxes checked.

 

[Squid]

Or am I putting too much into this and I just need a Class A ceiling material? The flame-spread rating but not fire barrier might be tripping me up.

 

[Yikes]

OK, your issue is one of occupancy separation. You said "M" retail vs "B" office, but if the first floor function is a restaurant, then under today's code it is likely an "A" (Assembly) occupancy, not an M occupancy.

I don't know what code (if any) would have been in effect at time of original construction, but as an example here's an excerpt from the 1928 Uniform Building Code, showing that office buildings and restaurants had the same occupancy classification, which back then was called "F-1":


It is quite possible that under the applicable building code for your building, changing from an office to a restaurant is not considered a change of occupancy.

You mentioned that your called "code enforcement". Out here in So Cal, "code enforcement" is the people who get called when the neighbor is doing illegal dumping or making too much noise, or doing factory work in their residential garage. They are not usually who I would call to as an IBC occupancy change question.

You didn't name the city your building is located, so I can't be of much more help. But if it were me, I would not start by calling code enforcement, I would call the building department and ask for a meeting with the building official about a potential alteration. Prior to that meeting, ask for a copy of all the records they have on your building especially and certificates of occupancy.

At that meeting:

• Ask which building code was applicable at time of certificate of occupancy.
• Ask if their currently adopted codes (which may include the International EXISTING Building Code and maybe some Historic Building Code) will allow the occupancy separations to be based on what was required at time of original occupancy.

 

[steveray]

What State and do you have/ need a designer?

 

[Paul Sweet]

Type X (fire-rated) drywall could be used if a rating is required, with a lay-in grid ceiling suspended below for looks.

Fire-rated drop ceilings are more complicated than unrated ceilings. In addition to the grid & tiles being fire-rated, you have to put "tents" over recessed lights and use ceiling radiation dampers with a dynamic rating for HVAC grilles.

Ask the building department what edition of the codes they enforce, and whether there are any state or local amendments. Also ask if they use the International Existing Building Code for renovations.