Combustible Ceiling in Condo or Type 1B Construction

[jar546]

Constructed not per approved plans that were by the architect which did not show any combustible framing and now they want to do this and asking for approval so they can have the architect draw it like this and submit it. I am not aware of any exceptions to the requirements of 803 & 805 and have yet to see data on LDF that supports compliance with 803.
Thoughts?

 

[RLGA]

Does “LDF” mean “low-density fiberboard” (i.e., particleboard)?

 

[steveray]

Could possibly meet this...ish:

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.
803.13.1.1 Furred construction. If the interior finish
material is applied to furring strips, the intervening
spaces between such furring strips shall comply with
one of the following:
1. Be filled with material that is inorganic or noncombustible;
2. Be filled with material that meets the requirements
of a Class A material in accordance with
Section 803.1.1 or 803.1.2; or
3. Be fireblocked at a maximum of 8 feet (2438
mm) in every direction in accordance with Section
718.

 

[cda]

Constructed not per approved plans that were by the architect which did not show any combustible framing and now they want to do this and asking for approval so they can have the architect draw it like this and submit it. I am not aware of any exceptions to the requirements of 803 & 805 and have yet to see data on LDF that supports compliance with 803.
Thoughts?
View attachment 7387

If wood is combustible, are they creating a combustible void space, that would require fire sprinklers above and below???

 

[jar546]

Does “LDF” mean “low-density fiberboard” (i.e., particleboard)?

I believe so. Still waiting on data from mfg.

 

[RLGA]

If they use fire-retardant-treated particleboard, then that should be okay, since they usually have a Class A rating.

As for the furring, I don't see the need for any wood. Many manufacturers of metal framing provide 1-1/2 hat furring channels like this one: https://www.clarkdietrich.com/products/furring-channel-hat-channel.

 

[Tim Mailloux]

If they use fire-retardant-treated particleboard, then that should be okay, since they usually have a Class A rating.

As for the furring, I don't see the need for any wood. Many manufacturers of metal framing provide 1-1/2 hat furring channels like this one: https://www.clarkdietrich.com/products/furring-channel-hat-channel.

I'm guessing that the ceiling finish may be a tounge and groove product that gets installed with nails, hense the solid wood blocking.