# rated corridor assembly



## cda (Aug 15, 2011)

Anyone have a ul design for a one hour corridor with rated ceiling tiles???

or a link to ceiling tiles that are rated for use as the ceiling in a one hour corridor???


----------



## mark handler (Aug 15, 2011)

http://www.usg.com/donn-fineline-dfx-dxlf-suspension-system.html

Fire resistance ratings apply to a floor/ceiling or roof/ceiling assembly in its entirety. Individual components, such as ceiling panels or suspended grid systems, are not assigned fire resistance ratings.

http://www.armstrong.com/commceilingsna/browse_perf_fire.jsp


----------



## cda (Aug 15, 2011)

Ok mark. I may be reading the links wrong

I have only seen it done two times, and many moons ago

The walls went a little above the ceiling, and the one hour ceiling was achieved using rated tiles, but they also had to be clipped/ held down to the track


----------



## mark handler (Aug 15, 2011)

cda said:
			
		

> The walls went a little above the ceiling, and the one hour ceiling was achieved using rated tiles, but they also had to be clipped/ held down to the track


Per the listing.....

I have specified both products I provided links for and yes they need clips

You need to get a copy of the listing, for the product specified.

An example:

http://www.usg.com/rc/evaluation-reports/suspension-systems/donn/icc-evaluation-services-report-1222.pdf


----------



## cda (Aug 16, 2011)

Thanks will read it more closely

Been a very long time since having to deal with it


----------



## cda (Aug 16, 2011)

further research::

Are hold down clips necessary when following a UL design?

Amstrong Fire Guard ceilings do not require the use of "hold down" clips in a UL design. Hold down clips are only required for UL assemblies in which the ceiling panels weigh less than 1.0 lb./square foot. All Armstrong Fire Guard ceilings weigh 1.0 lb./sq.ft. or more and do not require hold down clips.

How do I obtain an hourly rating for a corridor?

Below is a list of construction practices used in the industry to obtain an hourly rating for a corridor:

•If the corridor walls do not go to the deck, find the appropriate UL Design and install the specified fire-resistive ceiling and fire-resistive grid in corridor ceiling and adjacent areas.

•If the walls in the corridor run to the deck above, find the appropriate UL Design and install the specified fire-resistive ceiling and fire-resistive grid in the corridor ceiling; fire-damp where walls are penetrated.

•Install two layers of gypsum board in the corridor ceiling WITH CODE OFFICIAL APPROVAL, or reference the current 1997 Uniform Building Code section 1004.3.4.3.1 (2), page 1-115 Volume 1.

  The above construction practices should be reviewed with your local Code Official before construction.

http://www.armstrong.com/commceilingsna/article21342.html


----------



## texasbo (Aug 16, 2011)

cda said:
			
		

> ...If the walls in the corridor run to the deck above, find the appropriate UL Design and install the specified fire-resistive ceiling and fire-resistive grid in the corridor ceiling; fire-damp where walls are penetrated. http://www.armstrong.com/commceilingsna/article21342.html


I don't understand why the armstrong literature includes this. Per 708, this would only be required if the room side fire resistance rating continued to the deck above, and the corridor side rating did not. If the rated walls (both sides of framing) continue to underside of deck, a separate rated corridor ceiling is not required, unless you're using the area above as a plenum.


----------



## cda (Aug 16, 2011)

maybe depends on what the deck is made of????? and if you are in a multi story building??


----------



## texasbo (Aug 16, 2011)

Or to sell more ceiling tiles...

On further review, I don't understand this either:

"Install two layers of gypsum board in the corridor ceiling WITH CODE OFFICIAL APPROVAL, or reference the current 1997 Uniform Building Code section 1004.3.4.3.1 (2), page 1-115 Volume 1. "

Sorry, but I'm not approving 2 layers of sheetrock on the corridor side; the code clearly allows a ceiling constructed "as required for the corridor walls". I'm not interested in providing extra sheetrock to protect the rooms from the corridor...


----------



## Examiner (Aug 16, 2011)

UL floor/ceiling assemblies are tested for the entire floor/ceiling and as I understand are to be continued to all exterior walls not just across a corridor or room that has rated enclosing walls.  Although the Code allows you to rate a floor/ceiling assembly from one rated corridor wall to the other rated wall across the span of the corridor I do not endorse such a practice with UL floor/ceiling assemblies.  There are issues with floor joist penetrations of the rated wall regarding adequate firesafing and exceeding the allowable ceiling penetration area with lights and HVAC.  If you have to have a rated corridor cap then I usually use a horizontal shaft wall or a light gauge joist framing systems that are floor/ceiling assemblies and bear on the rated corridor wall.  Not just laying a drywall stud over the corridor.

If you have a rated UL floor/ceiling just across the corridor and the corridor wall does not go up to the underside of the deck you would have an open space above the corridor wall and the fire can spread over the corridor if the floor/ceiling assembly is not contiguous through out the building.


----------



## Paul Sweet (Aug 16, 2011)

The only way I know of to get a rated ceiling if the walls don't go to the deck is to use a "horizontal shaftwall"

http://nationalgypsum.com/products/..%5CFile%5Cistudareawall.pdf

If the rated walls don't go to the deck, a fire in a room can melt the wires holding up the tile ceiling.


----------

