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drops to sprinklers through 1hr ceiling

drops to sprinklers through 1hr ceiling

drops to sprinklers through 1hr ceiling

If you install a branch line above a 1 hour rated ceiling, and then have drops to sprinklers at the ceiling, are you required to provide fire caulk around the penetrations at the ceiling?


RE: drops to sprinklers through 1hr ceiling

if the owner tells you.

there are allowable penetrations through the one hour rating otherwise there would be no lights and other items in ceilings, although some do carry a rating for the housing.

do not have the current code but in 97 ubc the exception is in 710.2.1 should be similar exception in ibc or whatever code the building is under.

RE: drops to sprinklers through 1hr ceiling

The 2003 IBC reference is Exception 3 to Section 712.3.2 where a metal escutcheon plate is provided, covering the annular space.

RE: drops to sprinklers through 1hr ceiling

That's not what the exception means. Its only for membranes. IBC 702 defines a membrane penetration as An opening made through one side (wall, floor or ceiling membrane) of an assembly.

IBC 702 defines a through penetration as An opening that passes through an entire assembly. Travis's piping is penetrating a horizontal assembly based on the explanation. If so, it is a through penetration and I would require a 1-hour through penetration fire stop assembly. See IBC 712.3.1.2.

RE: drops to sprinklers through 1hr ceiling


You are starting to frighten me.

I think, actually assuming, all building codes require some sort of rating between a combustible attic space and the area below.  

We have a single story hotel that has a combustible attic. Assume the attic is equipped with sprinklers and we run our pipe feeding the pendent sprinklers below what you are saying is since the penetrations for the pendent sprinklers are through the assembly, assume 2 layers of 5/8" sheetrock, these need to be fire stopped?

If this is so it doesn't happen anywhere I am aware of.

For the first time I really want you to tell me I am wrong.

RE: drops to sprinklers through 1hr ceiling


In the case you described, the ceiling is most likely not a 1-hour horizontal assembly. Its just a ceiling. Your installation complies with NFPA 13 and Chapter 7 of the IBC, which governs fire-resistance rated construction. Two layers may have been applied because of energy code implications or the architect was trying to reduce the sound transmission level.

My recommendation to fire protection design professionals is to be sure to know where vertical and horizontal assemblies are located. When you penetrate them, a through penetration fire stop assembly is generally required. This can be difficult, especially in older buildings without architectural plans. In this case, I recommend retaining a fire protection engineer or an architect so that height and area calculations can be performed to determine if the wall is a fire partion, fire barrier or fire wall or if horizontal assemblies are required.

What Travis has is a ceiling that was constructed as a 1-hour horizontal assembly. You will usually find these in corridors that have excessive travel distances. You can also find these in the floor/ceiling assemblies of high-rise buildings. If they are penetrated, then a through penetration fire stop assembly is required.

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