Running Mc in concrete decked drop ceiling

[Flex]

I am running MC fixture to fixture in a drop ceiling with a concrete deck. I dont want to tapcon the mc with one holes to the concrete deck but I cant think of any other way to support the MC. The ceiling isnt up yet so I figured i get ahead of them. I thought about when shooting my fixture supports in the deck for the fixture tie ups maybe shooting extra to tie the MC to. Figured Id ask for some other ideas.

[electricalperson]

I am running MC fixture to fixture in a drop ceiling with a concrete deck. I dont want to tapcon the mc with one holes to the concrete deck but I cant think of any other way to support the MC. The ceiling isnt up yet so I figured i get ahead of them. I thought about when shooting my fixture supports in the deck for the fixture tie ups maybe shooting extra to tie the MC to. Figured Id ask for some other ideas.

would these be of any use http://www.arlcatalog.com/Flex/Steel%20Cable%20Hangers.htm

[Flex]

Nice find. If i had more than one cable to jump around they seem like they would be perfect. However I have only one 12-2 MC jumping around light to light. Looks like one-holes it is.

[ultramegabob]

I would probly just use one hole straps and a powder actuated nail gun.

[Flex]

Do I need a license?

[ultramegabob]

Do I need a license?

for what? the powder actuated nail gun? I dont where I live, you may want to check your local laws, it isnt a firearm...

[cadpoint]

With new concrete I'd go with a lead pin or a lead set anchor and drilled, the concrete won't be cured for a shoot! unless it's old construction...

See if you can get the PSI of the concrete it matters to the shoot.

[JFletcher]

Do I need a license?

Probably not, but you ought to get a safety certification for the specific tool you use. See OSHA 1926.302(e).

[iwire]

We would shoot it using a viper and ceiling tie wires that already have a pin connected to them.

http://constructionfastening.com/images/viper_pole_guy_1_.jpg


http://constructionfastening.com/powder.html


Or if we want to use bridal rings we shoot these clips into the deck.


http://constructionfastening.com/images/SPC114_1_.jpg

[ultramegabob]

With new concrete I'd go with a lead pin or a lead set anchor and drilled, the concrete won't be cured for a shoot! unless it's old construction...

See if you can get the PSI of the concrete it matters to the shoot.

I think his original idea of tapcons would cost less and be less labor intensive

[iwire]

I have no issue with green concrete just use the right charge. I will take green concrete over 100 year old concrete any day. That old stuff likes to blow out instead of holding fast.

[ultramegabob]

I have no issue with green concrete just use the right charge. I will take green concrete over 100 year old concrete any day. That old stuff likes to blow out instead of holding fast.

I will second that....

[ultramegabob]

Or if we want to use bridal rings we shoot these clips into the deck.


http://constructionfastening.com/images/SPC114_1_.jpg

what do these bridal rings you would use with these clips look like? would there be a problem with just using tie wire to hold the m.c. up with those? I wouldnt do it out in the open, but he said it was above a suspended ceiling.

[jeremysterling]

Here in Austin, troffers are independently supported from the grid. We paint our ceiling wires yellow and shoot them up with the powder-actuated tool, either with a lift or pole-gun. We use 7/8" drive pins to stay shallower than the post-tension cables in the slab. Each troffer is required by municipal code to be supported on all four corners. We use a lot of MC "batwings".

I shoot additional wires and tie them to the grid for "batwinging" homeruns, switchlegs, emergency and nightlight ckts. The inspector looks to make sure all electrical is on yellow painted ceiling wire.

[iwire]

I don't see any real problem with just using tie wire and I do that often. :smile: But bridal rings are handy, easer to add cables to and I think the job can come out looking better.


http://www.erico.com/products/CADDYcfcFlexibleConduitCableHanger.asp


http://www.erico.com/public/images/products/FF-Datacomm/NorthAmerica/146061.jpg

[ultramegabob]

I don't see any real problem with just using tie wire and I do that often. :smile: But bridal rings are handy, easer to add cables to and I think the job can come out looking better.


http://www.erico.com/products/CADDYcfcFlexibleConduitCableHanger.asp


http://www.erico.com/public/images/products/FF-Datacomm/NorthAmerica/146061.jpg

I have never used that type of bridal ring before, all the ones I have used were screwed into beam clamps or had a wood screw tip on them, I will have to remember those, thanks!

[ultramegabob]

I shoot additional wires and tie them to the grid for "batwinging" homeruns, switchlegs, emergency and nightlight ckts. The inspector looks to make sure all electrical is on yellow painted ceiling wire.

I think he is wanting to get his cable up before the ceiling grid is installed.

[Doug S.]

With new concrete I'd go with a lead pin or a lead set anchor and drilled, the concrete won't be cured for a shoot! unless it's old construction...

See if you can get the PSI of the concrete it matters to the shoot.

Make sure lead / zinc / not steel is ok per your local code. Some folks don't like it, because the heat (fire) will melt the anchor ... ... ... and you get the point.

You can shoot into new concrete. The newer the better for the product that iwire showed. OLD concrete like's to make a mess when shooting into it...ack.


Just shoot it, you'll be happy and amazed at the labor savings.

[tim123]

We typically use the viper like iwire does. Trying to make massive vertical racks of mc and kx clips to cut down on labor. However from time to time we are not allowed to use that gun, something about the nail being to long and possibly hitting post tension cables. :rolleyes: In that case we use a t3 nail gun, that usually blows the concrete out a bunch and makes for a rough couple of weeks.
http://toolmonger.com/wp-content/uploads/2006/10/ramset-t3.jpg

[electricalperson]

We typically use the viper like iwire does. Trying to make massive vertical racks of mc and kx clips to cut down on labor. However from time to time we are not allowed to use that gun, something about the nail being to long and possibly hitting post tension cables. :rolleyes: In that case we use a t3 nail gun, that usually blows the concrete out a bunch and makes for a rough couple of weeks.
http://toolmonger.com/wp-content/uploads/2006/10/ramset-t3.jpg

what are post tension cables and what happens if they get hit?

[iMuse97]

what are post tension cables and what happens if they get hit?

cables in the concrete for strength that are tensioned after installation and pouring and curing, unlike rebar which just stays there.

[iMuse97]

what are post tension cables and what happens if they get hit?

O yeah, and when they get hit, they are compromised and could break and/or lose tensile strength when they are tensioned.

[tim123]

like karl said.. he knows more about it than me I'm sure. I have heard some stories that are probably bs, but anyways... about it being under 25000 lbs of tension and being hit and flying out the building... I could only find a few pics of them coming out the concrete a little bit. We had hit 3 of them doing a 1 foot core drill and all I heard was the floor popping I was underneth catching cores, the guy doing the drilling said he felt the floor give a little bit. To fix it they chipped out the area around where it cut and had to replace the cables.

[texassparky]

This is what we have been using for multiple runs of mc

http://i908.photobucket.com/albums/ac281/texassparky/support_brackets1.gif

for single runs I would stick with a pole gun, if powder actuated then yes you must be licensed to use it, however they make CO2 actuated that you do not have to be. some places will let you use the tool for free if you buy the fasteners from them

[quogueelectric]

I am running MC fixture to fixture in a drop ceiling with a concrete deck. I dont want to tapcon the mc with one holes to the concrete deck but I cant think of any other way to support the MC. The ceiling isnt up yet so I figured i get ahead of them. I thought about when shooting my fixture supports in the deck for the fixture tie ups maybe shooting extra to tie the MC to. Figured Id ask for some other ideas.
Use a hilti gx 100 or gx 120 Gas operated track fastener is extremely fast as fast as you can pull the trigger it fires. We also used to use the ceiling pole powder actuated tools with a washer and tiewire long enough to strap about 10 cables every 6 ft for mc cable.

[ultramegabob]

for single runs I would stick with a pole gun, if powder actuated then yes you must be licensed to use it, however they make CO2 actuated that you do not have to be.

who do you get licensed with? I dont really understand having to get a license for a hand tool.

[Flex]

Ive never seen that style of bridle ring before either. I think for just this single mc I am gonna go witht he tapcons though. Light tails are the only thing allowed in MC. All other power must be in conduit so no need the set up for future MC's.

[nakulak]

who do you get licensed with? I dont really understand having to get a license for a hand tool.

you can usually have a hilti rep come to the site and give a short training session for powder actuated tools, they give a little test, and the guys get a little card that says they are licensed to use them. basically it gives the employer a better position if someone gets hurt. for example, most eye injuries are because guys don't wear safety glasses. nails in people's heads are because they shot to a round post or used a powder tool on hollow wall and shoot nail through wall into someone's head, etc. (all this stuff is probably in the operator's manual, but who reads that ?)

a few years back this was slightly more important because the powder tools were high velocity and more people got hurt. now they are low speed, but they can still kill people.

[LarryFine]

http://www.erico.com/public/images/products/FF-Datacomm/NorthAmerica/146061.jpg
Wow! A corn-on-the-cob hanger. ;)

[LarryFine]

cables in the concrete for strength that are tensioned after installation and pouring and curing, unlike rebar which just stays there.Is that the same as pre-stressed concrete? I remember years ago working under a guy who cut a cable core-drilling a floor. You could hear the "twang!" all through the building. I don't remember ever hearing anything about repairing or replacing it. 8-)

[macmikeman]

For a single run I'd go with the independant support flagged grid hanger wires shot just like how Iwire shows. For multi runs there is some nice pics of nice gear shown here but I used to use another way frequently. I would hang 1/8" threaded rods and then use plain old "bat wings" one above the other. Lets see if I remember- Caddy k12 for 1/2" pipe. I don't know if they make a smaller size for 3/8" diameter cables but I bet they do. A box of those bat wings did not cost very much.

[Smart $]

Is that the same as pre-stressed concrete?...
http://en.wikipedia.org/wiki/Prestressed_concrete

I wouldn't think you'd hear a "twang" with pre-stressed. Perhaps a thud if the cable gives abruptly.

[Smart $]

Lets see if I remember- Caddy k12 for 1/2" pipe. I don't know if they make a smaller size for 3/8" diameter cables but I bet they do.
Not bad recall... but it depends on size of wire or other being attached to. And they do make smaller... K8 and KX

http://www.erico.com/products/CADDYcfcConduitHangers.asp

[LarryFine]

http://en.wikipedia.org/wiki/Prestressed_concrete

I wouldn't think you'd hear a "twang" with pre-stressed. Perhaps a thud if the cable gives abruptly.I think this was the last kind, the unbonded post-tensioned cable. It was not just a thud.

[Flex]

I would think just tapcons and one holes would be the fastest, I dont know about cheapest though.

[ultramegabob]

I would think just tapcons and one holes would be the fastest, I dont know about cheapest though.

I dont see how drilling a pilot hole, then changing over to a driver and driving a tapcon screw would be faster than using a powder actuated nailgun, BANG! done...

[Flex]

Tapcon tool for a bulldog makes things pretty quick.

[ultramegabob]

I agree tapcons are "pretty quick" but you said the fastest;)

[Flex]

I dont think we have the tool in our shop. I think its on another jobsite. For the 20 straps I have to put in I guess Ill just use the bulldog.

The tool being a powder actuated gun

[ultramegabob]

yeah, if its just 20 I would just use the tool that you have, if it were 200 I would be more concerned the labor differnce...

[JohnJ0906]

you can usually have a hilti rep come to the site and give a short training session for powder actuated tools, they give a little test, and the guys get a little card that says they are licensed to use them. basically it gives the employer a better position if someone gets hurt. for example, most eye injuries are because guys don't wear safety glasses. nails in people's heads are because they shot to a round post or used a powder tool on hollow wall and shoot nail through wall into someone's head, etc. (all this stuff is probably in the operator's manual, but who reads that ?)

a few years back this was slightly more important because the powder tools were high velocity and more people got hurt. now they are low speed, but they can still kill people.

We just did this at the company I work for, as a matter of fact.

I also have the card for my Ramset. For some of the manufacturers, this can be done on-line.

[c2500]

I have a buddy that works for a GC firm. On a job in Asheville, NC they are doing, the plumber missed a few holes, and decided to core drill. I can't remember, but it was either $8000 to replace the cable or $25,000. Needless to say, I would not want that one on my insurance.

c2500

[mcclary's electrical]

Tapcons less labor intensive than shooting it????????you're wrong,,,,I'll take my remington and run circles around your tapcon

[Flex]

BY the time you get the remington to the jobsite Ill have the tapcons in.