fire sealing multiple SER penetrations

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kenman215

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albany, ny
I have an apartment building that I'm starting next week which has an electrical room on the lower of two parking levels. I have to pass 115 2/0- 3/0 SER cables through two levels of an 8" concrete floor/ceiling before getting to the first of 4 stick - framed residence levels. Typically speaking, as a company, we would drill a hole for each of the cables, sealing each one individually with fire caulk. There has to be an easier way than core drilling 230 rimes through four layers of rebar...

I've done research through fire sealant manufacturers, and the best solution I've seen so far has been to drill 4 1/2" with three SER'S running through the center, sealing around the bundle. Granted it's a third of the drill time, but I wanted to see if anyone knows of a cable tray-type methodology that would be code compliant, and where I might be able to find some reference materials to forward to my PM.
 
Lately we've been using fire barrier mortar to seal vertical floor penetrations. Can you use a larger hole and install more SER cables in each hole?

3mtm-fire-barrier-mortar.jpg


http://solutions.3m.com/wps/portal/...re-Barrier-Mortar?N=8710081+3293123922&rt=rud
 
That's a lot of holes through the floor, just double check for it being acceptable before making it Swiss cheese.
 
I'd too worry about all those holes.
I'd check with the engineer and get approval before drilling.
 
This swiss cheese isn't ideal, but structurally fine. Holes would be in what was originally engineered as an open chase. Checked on that one right off the bat. Thanks for the concern though.
 
kenman215 said:
This swiss cheese isn't ideal, but structurally fine. Holes would be in what was originally engineered as an open chase. Checked on that one right off the bat. Thanks for the concern though.
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Then make the jackwagon who filled it in pay for a concrete cutting contractor to come fix his work.
 
If it's 2 stories of concrete parking and 4 stories of stick built above (which sounds odd from a construction type perspective but that's not on the table) the lowest level of firestopping should occur at the underside of the stick built.

You can drive a car from one level to the next in the parking area. Why can't you run a pipe?
 
Mcgookin, absolutley right about lowest fire rated level being first stick framed floor. We've gotten jammed up before on just running through a big cut out in a floor and trying to seal around all the cables before, but I'm thinking that maybe we cover the cutout with a couple of layers of 1 hr rated gyp board, PL it to the floor, and caulk the edge. Hole sawing individually would be a breeze and I think it might meet fire rating criteria. Thoughts?
And by the way, two levels of parking is really only one full level. There's a large student center, a clubhouse with large workout facility, with tanning beds, and all the mechanical utility rooms located on those levels as well.
 
kenman215 said:
Mcgookin, absolutley right about lowest fire rated level being first stick framed floor. We've gotten jammed up before on just running through a big cut out in a floor and trying to seal around all the cables before, but I'm thinking that maybe we cover the cutout with a couple of layers of 1 hr rated gyp board, PL it to the floor, and caulk the edge. Hole sawing individually would be a breeze and I think it might meet fire rating criteria. Thoughts?
And by the way, two levels of parking is really only one full level. There's a large student center, a clubhouse with large workout facility, with tanning beds, and all the mechanical utility rooms located on those levels as well.
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Installing gypsum board on the floor of a parking garage is not going to last very long.

Now it seems like we're just talking about filling the hole back in around the pipes to make it nice. That makes sense.

Do you know what kind of concrete reinforcement it is?

If it's cold formed reinforcement (rebar) you could leave the reinforcement in place when you do the cutout and then repour the concrete around the pipes to put the floor back and make it look good and last forever. But cold formed reinforcement is not common in parking garages so let's keep thinking here...

If there is no reinforcement (as if the concrete plant left that area void of reinforcement but then poured it solid) you could do your cutout, run your pipes, then support reinforcement spanning the opening above, form it from the bottom, and pour it back with concrete. This will create a raised elevation in that area which should be fine. You'll need minimum 1-1/2" concrete cover on the rebar (above and below) which means that area will be raised by 3" + diameter of rebar. For a short distance you can get away with #4 rebar (1/2") but #5 may be easier to find. So you'll have about a 4" raised area around your cutout. Your form at the top should provide a good 6" all around extension beyond the opening.

If it requires cutting any existing reinforcement I'd put it on the structural engineer and GC to produce a shop drawing for the work. They're likely to suggest something like the above paragraph.

Whichever you decide on, good communication with the GC would be a good idea.
 
Not a bad idea. The floor is completely reinforced. I'm definitely going to the g.c. with it, but typically, when I send something out for RFI, I like to know that the answer to my suggestion is going to be yes beforehand. Remember that we're talking SER cables here not pipes, so I'm thinking that I like the cutout and fill idea, just with fire-caulkable pipe sleeves. Thanks for the input.
 
kenman215 said:
Not a bad idea. The floor is completely reinforced. I'm definitely going to the g.c. with it, but typically, when I send something out for RFI, I like to know that the answer to my suggestion is going to be yes beforehand. Remember that we're talking SER cables here not pipes, so I'm thinking that I like the cutout and fill idea, just with fire-caulkable pipe sleeves. Thanks for the input.
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And you can use plastic or metal pipe. I'd probably go with plastic with a bell or coupling at the top to keep it from ever sliding down if (when) the concrete shrinks. All concrete shrinks when curing. You can get hydraulic grout which is supposed to be non-shrinking but you'll always have gravity acting on that sleeve. Plus metal may corrode and look nasty over time being in contact with concrete which holds moisture which contains elements which cause corrosion.

You're welcome.

And welcome to the forums!
 
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