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Discussion Starter · #1 ·
I just did my sub elec room, and sec/tel room in slab. I had 6 - 2 inch emt 90's stubbing down, 6- 3 inch emt 90's stubbing down into these rooms.

for a 2 inch 90 i drilled a 3 inch hole, and 3 inch i drilled a 4 inch hole so when the forming was stripped the conduits were not damaged. The conduits were tied with tie wire very tight on the slab, and underneath they were tied as well with tie wire.

with stubbing up i usually just build a rack and it seems to work fine, i add rigid foam around the stub ups in case of other trade damage, it gives me room to add couplings etc.

I would like to find a method that would completely prevent the pipes from moving when the concrete placement happens.

any suggestions would be great :)
 

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Sparkshow Vancouver said:
I just did my sub elec room, and sec/tel room in slab. I had 6 - 2 inch emt 90's stubbing down, 6- 3 inch emt 90's stubbing down into these rooms. for a 2 inch 90 i drilled a 3 inch hole, and 3 inch i drilled a 4 inch hole so when the forming was stripped the conduits were not damaged. The conduits were tied with tie wire very tight on the slab, and underneath they were tied as well with tie wire. with stubbing up i usually just build a rack and it seems to work fine, i add rigid foam around the stub ups in case of other trade damage, it gives me room to add couplings etc. I would like to find a method that would completely prevent the pipes from moving when the concrete placement happens. any suggestions would be great :)
. I assume you ran these conduits on a metal pan deck before concrete was poured ? If that's the case , my first question is why EMT and not PVC with a rigid sweep going through the deck ? EMT is usually not allowed in concrete around here and for good reason . Concrete will eventually rot that away and make removing or adding wires next to impossible . Anytime I've done this I've one hole strapped the pipes to the pan deck at close intervals . Drill a tighter hole for the 90 to stub down to take done of the wiggle out of it . The only way to keep them perfect is to clamp them from the underside with strut , so they're all tied together . Not sure I answered your question or not ?
 

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Discussion Starter · #3 ·
I agree that EMT is not a good choice for installation in concrete. What we do here is run DBII and transition to emt or pvc for any EM or Fire alarm Feeds. we can also stubb down in PVC. with the sheer amount of conduit being used my company has chosen to use DBII for cost reasons. These buildings are residential Highrise so im a little confused what application do you use the metal pan on the deck? is this a Q-deck install? The only concern with using a smaller hole is when the forming is stripped the pipes are damaged more often than not.

Thanks for your reply
 

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Sparkshow Vancouver said:
I agree that EMT is not a good choice for installation in concrete. What we do here is run DBII and transition to emt or pvc for any EM or Fire alarm Feeds. we can also stubb down in PVC. with the sheer amount of conduit being used my company has chosen to use DBII for cost reasons. These buildings are residential Highrise so im a little confused what application do you use the metal pan on the deck? is this a Q-deck install? The only concern with using a smaller hole is when the forming is stripped the pipes are damaged more often than not. Thanks for your reply
. Well , probably the most common practice around here for multistory buildings is a layer of corrugated decking ( pan deck ) goes down , then electric , plumbing and hvac , are run and marked out for openings . Concrete is poured over the deck , so there are no forms to strip . I've been on poured in place jobs too , but lately they seem to be too time consuming and expensive for owners to go for if they're working on a tight budget . So you're running direct burial cable a d just stubbing up or down with a PVC or EMT sweep ? Still not sure I'm following you ?
 

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Discussion Starter · #6 ·
We either place tech cable or ACWU in the concrete, or run the thinn wall DBII PVC conduit in slab then pull individual conductor to equipment. I think the metal decking would be nice to work with the way your describing. we do very little of that for our slab work.

Thanks for your replies, i appreciate it.
 

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360max said:
<a href="http://www.youtube.com/watch?v=ClESOBeKt2s">YouTube Link</a>
. This is a fire rated sleeve for a through slab penetration . Not the same as stubbing up or down from a slab . These are nice though . I wonder how much more they are than standard screw down sleeves ?
 
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