patching cores in concrete floors

[Sifu]

Many times I have seen DP's issue specifications for patching rated concrete floors and I can only recall ever seeing non-shrink grout or hydraulic cement specified. It may be that every time the floors have fallen under the edict of 602.1, which says openings in such rated elements are not required to be protected. But a question was posed to me today about filling a core in a rated floor assembly. Assuming the floor is required to be rated by a different section of code...say for occupancy separation, what would be done? An existing core hole is not a penetration, so a penetration firestop system would not apply??? Would we just look to the assembly to be restored with the same material? An EJ? Bubble gum and saw-dust?

 

[e hilton]

Why is an existing core hole not a penetration?

 

[steveray]

Treat it like a really small steel penetration.....

714.4.1 Through penetrations. Through penetrations of
horizontal assemblies shall comply with Section 714.4.1.1
or 714.4.1.2.

Exceptions:

2. Penetrations in a single concrete floor by steel,
ferrous or copper conduits, pipes, tubes or
vents with a maximum 6-inch (152 mm) nominal
diameter, provided the concrete, grout or
mortar is installed the full thickness of the
floor or the thickness required to maintain the
fire-resistance rating. The penetrating items
shall not be limited to the penetration of a single
concrete floor, provided the area of the
opening through each floor does not exceed
144 square inches (92 900 mm2).

 

[Sifu]

Why is an existing core hole not a penetration?

By definition from the IBC. But I understand the debate. Maybe they should be considered through-penetrations...maybe because there used to be a penetrating item, or there could be? But without an item "passing though both breaches", it doesn't meet the definition. I find it interesting that there are "through-penetration firestop systems" for breaches with "no penetrating items" in UL, which seems a little counter-intuitive based on the IBC definition.

 

[mtlogcabin]

This is the definition of a trough penetration
[BF] THROUGH PENETRATION. A breach in both sides of a floor, floor-ceiling or wall assembly.............
This is the reason to have a through penetration to accommodate an item passing through the breaches.

If you do not have an item that passes through the penetration then you have an opening in a floor ceiling assembly. So how big is the hole and is it in an area that the fix will have to meet the floor loading requirements?

 

[Mark K]

If a penetration is patched using a cementitious material consistent with the slab we should assume that the penetration no longer exists and any code provisions related to penetrations are not applicable.

 

[steveray]

If a penetration is patched using a cementitious material consistent with the slab we should assume that the penetration no longer exists and any code provisions related to penetrations are not applicable.

Hence my answer....If it complies with a piece of conduit in it concreted around, Shirley it complies without the conduit, concreted around....Or maybe the conduit is just too small to see with the naked eye....

 

[Sifu]

Truly penetrating discussion. I think IBC 714.5.1 makes sense up to a point, which the code defines as 6". This is not regarding the structural element, and that is where the DP must step in. Never one to add more words to the code, but it seems like this could be addressed with revised or new definitions. we have discussed in other threads the lack of a definition for an opening, maybe that would help here.