Supporting Stub-ups in concrete slab

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Robd58

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I was wondering what the different methods of supporting conduit Stub-ups emerging from a concrete slab are around the country. In my experience (which is primarily high rise deck work) we use Candy's FBS-12, or FBS-16 to tie our conduit to. Is this similar to how it's done elsewhere? Thanks!
 
Very cool, thank you for the pics. I guess more specifically I was looking for info regarding deck slabs not slabs on grade, or below grade. But thank you for the quick reply.
 
Cow said:
This is how we do it:
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I realize that in this trade you don't necessarily get extra points for neatness, but WOW! I see conduit stacked 3 high in some spots. Is there going to be enough cover after the pour?
 
Ground to 1st floor to be in concrete, RMC 90's to vertical runs;

I had to use come-a-longs to hold vertical stack for pour.

If you look at door opening it looks like it'll be a 8" pour.
 
cadpoint said:
Ground to 1st floor to be in concrete, RMC 90's to vertical runs;

I had to use come-a-longs to hold vertical stack for pour.

If you look at door opening it looks like it'll be a 8" pour.
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I'm not sure you have 8" based on that door frame, but say you did. Most of that looks like not less than 3/4" EMT. At 0.842" ID and 0.049" wall, you're looking at 0.922" OD. Some spots have four (4) conduits crossing over. And the slab doesn't look like it's getting any reinforcement. So now you have 2 - 4" of cover in an un-reinforced slab. What could possibly go wrong? :eek:hmy:
 
No one has answered this question. The op is looking for how to support conduit runs when you are in the middle of a floor and the slab is on a second floor. I am not sure if there is something sold for this specific situation
 
Robd58 said:
I was wondering what the different methods of supporting conduit Stub-ups emerging from a concrete slab are around the country. In my experience (which is primarily high rise deck work) we use Candy's FBS-12, or FBS-16 to tie our conduit to. Is this similar to how it's done elsewhere? Thanks!
Click to expand...

I don't have any experience in this kind of construction so I went to Caddy's web site to take a look. How do you keep this stuff from getting ripped up after the pour is done? Somebody coming along with a job box could do some real damage.
 
harborrick said:
Looks like a Walgreen's project. Nice work ,we have done quite a few of them.
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This is the milking parlor equipment room for a 9000 cow dairy.

electrofelon said:
Are those metallic 90's on those smaller pipes? Is that going to be code compliant?
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Sure, why not?

FionaZuppa said:
wow, looks like crack city for that slab ??
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gadfly56 said:
I'm not sure you have 8" based on that door frame, but say you did. Most of that looks like not less than 3/4" EMT. At 0.842" ID and 0.049" wall, you're looking at 0.922" OD. Some spots have four (4) conduits crossing over. And the slab doesn't look like it's getting any reinforcement. So now you have 2 - 4" of cover in an un-reinforced slab. What could possibly go wrong? :eek:hmy:
Click to expand...

gadfly56 said:
I realize that in this trade you don't necessarily get extra points for neatness, but WOW! I see conduit stacked 3 high in some spots. Is there going to be enough cover after the pour?
Click to expand...

Are you guys aware of flowable fill(CDF)?

This should clear up any assumptions about cracking. You can see where slab height will be through the door opening. There is a 6" slab going on top of the fill.
 

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doesnt metal conduit need to be grounded? kinda a pita if you use metal between lenghts of PVC, no?

i understand the OP's Q, which i myself do not have answer for, but i would immediately be concerned about this conduit layout in a concrete slab, especially the one shown in the pics. i suspect a few saw cuts for relief after crete dries enough (can that even be done with conduit ~1/4 below the surface?), but wow, looks like problems to come later. i also assume that ground was properly compacted prior to conduit, which to me does not look like it as the ground would be very flat from all edges to center.

at best, questionable practices there??
 
Cow said:
This is the milking parlor equipment room for a 9000 cow dairy.
Sure, why not?
Are you guys aware of flowable fill(CDF)?
This should clear up any assumptions about cracking. You can see where slab height will be through the door opening. There is a 6" slab going on top of the fill.
Click to expand...
I knew what was going on there when you posted the first pictures. Not so much in particular that CDF was going to be used, but I've been involved with projects that used CDF. Other scenarios use so-called premium backfill... usually a mix of sand and pea gravel.
 
FionaZuppa said:
doesnt metal conduit need to be grounded? kinda a pita if you use metal between lenghts of PVC, no?

i understand the OP's Q, which i myself do not have answer for, but i would immediately be concerned about this conduit layout in a concrete slab, especially the one shown in the pics. i suspect a few saw cuts for relief after crete dries enough (can that even be done with conduit ~1/4 below the surface?), but wow, looks like problems to come later. i also assume that ground was properly compacted prior to conduit, which to me does not look like it as the ground would be very flat from all edges to center.

at best, questionable practices there??
Click to expand...

To answer your questions, no, not all metal conduit needs to be bonded to an equipment grounding conductor. It is VERY common practice to bury steel 90's in pvc runs. I don't take any chances with burning through 90's when it's under concrete.

Secondly, the dirt was compacted. When you run 50+ conduits in a small area like that, it's going to look a little chewed up on top from all the foot traffic, etc. There is no getting around that.

Smart $ said:
I knew what was going on there when you posted the first pictures. Not so much in particular that CDF was going to be used, but I've been involved with projects that used CDF. Other scenarios use so-called premium backfill... usually a mix of sand and pea gravel.
Click to expand...

Thanks, I'm glad a few on here get it.
 
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