Hanging 30' 40guage pipe from 4" concrete ceiling

[hobbsies]

I'm looking to hang a 40 guage 30' pipe (3 10' sections) from a concrete ceiling that is 4" thick. The purpose of this pipe is for a lighting position in a small blackbox space that has no more than 24 dimmers. The ceilings are about 10' tall, and I have, on one side of the space, a brick wall to attach to. My plan was to drill 7, 1/4" holes 5' apart into the concrete, and drop some eyehooks, attach trim chain around the pipe and attach to the eyehooks w/ shackles, and then screw one end of the pipe to the wall, but I'm looking for a more sturdy idea. Is there something I can use instead of chain and eyehooks so the pipe will be more rigid?

On a side note, I've read on the lighting forum that they frown upon rigging projects, similar to this one. Is this something I should be taking on? I primarily work as an electrician and carpenter on the side.

 

[MNicolai]

It's not that we frown on rigging -- it's that we want people doing rigging in a smart way that doesn't get people hurt. In your case, I'd suggest hiring a professional rigger (See here for a directory of ETCP-certified riggers) and consulting their expertise. This is one of those "If you have to ask, you should be consulting an experienced professional" kind of situations. That doesn't mean you should never ask -- there a lot of people here that like to talk in hypotheticals about proper/improper ways to do things, but for the sake of your project, you should be connecting with someone who does rigging as their primary profession.

Otherwise, when something goes wrong or there was something you didn't take into consideration (as even seasoned professionals are capable of doing), you are the one who would be liable for any/all damages and could very quickly end up in prison for any injuries given that injuries would be due to -- "gross negligence" is what I believe the appropriate legal term would be.

 

[derekleffew]

Seems to me that with a 10' ceiling, you're going to want the pipe as close to the ceiling as possible (leaving just enough room for the C-clamp to go over the pipe), so no room for an eyebolt, chain and shackles. I'd look into how sprinkler pipes are hung:

Clevis Hanger (CH)

Alternatively, you could gain a few inches by attaching Unistrut to the ceiling, and hanging your lights from that.


In either case, the attaching to the concrete ceiling is the tricky part, and for that, there's no substitute for engaging a structural engineer to ascertain a) whether it's possible at all, and b) the proper fasteners to use.

I'm looking to hang a 40 guage 30' pipe ...

"...a Schedule 40, 30' pipe..." would be more accurate. Note that if it's a 1.5" pipe, its external diameter measures 1.90".

 

[hobbsies]

Ok this is good to know. I'm going to suggest we hire a rigger to tell us how to do it, then do it ourselves. Thanks to both of you.

 

[MNicolai]

I would discourage you from that (remember that liability thing I was talking about?). There are things that a conversation with a rigger might tell you, that might be enough for you to get by, but things that may or may not come into the conversation that are crucial to the safety of the rigging and safety of the people below it include how bolts are rated, what sort of design and safety factors need to be taken into account, how many lift lines you might need and how strong each one and all of its components needs to be to prevent any single point of failure, and how heavy you'll be able to load the pipe once installed. Let's not forget that a sloppy job securing into the concrete immediately compromises the integrity of the entire rigging position.

My experience is that no rigger will just tell you all of the details about how they'd do it (not down to the details you'd need to safely copy their work), and then let you do it without charging them for the time they put into planning your project. They especially wouldn't let you just hire them to tell you how to do it and then perform the work yourself. Then they may be held partially liable in court if/when something goes wrong due to a poor execution of their plan. If you want this project done, hire a rigger to install it -- not just point at your ceiling and tell you how they'd do it. Chances are they won't even charge you just to show up onsite and look at it. I've had riggers in a couple times in the last year to perform various work, and something like this probably isn't all that expensive anyways.

Now is when I step in and point out our Terms of Service:

ControlBooth shall not be responsible for damage, injury or death resulting in any information posted on ControlBooth. When in doubt, always consult a qualified professional in person.

 

[jwl868]

Sorry to belabor the point but:

Anchoring into the concrete ceiling requires some sort of professional assistance, whether by an engineer or a contractor (who may well have an engineer on staff). The proper anchor must be used and the hole for that anchor must be properly drilled. There are other considerations about the concrete: was it designed for an additional load? Are there structural steel rods where you want to drill? Or is it precast concrete with voids (by design) or steel cable?


Joe

 

[DuckJordan]

To add to what everyone is saying, just because it looks like it could hold doesn't mean it can, I can't remember how many times I've seen people drill into concrete expecting solid architectural strength to find, it was just a face to steel beams. (think more of stucco). DO NOT ATTEMPT ON YOUR OWN!!! That is how people get hurt and worse killed, Which is doubly bad for you, you loose a few students or a worker plus the lawsuits comming from the families, plus if you work in a school district jail time and much more, Rigging is a specialty skill which is why they pay booku bucks to go to school for it then pay more $$$ to stay current and certified.

Think of it this way, would you trust your local hamberger griller to design a spaceship to send you to space?

 

[Footer]

Really, a rigger in this situation is not even needed. In fact, it would just give you a false sense of security. An ETCP certified rigger will not be able to tell you how much that ceiling will hold. Get a general contractor in their and have them hang the pipe. They will be able to properly secure it or at least put in the points to properly secure it. You say the ceiling is 4" thick, is the other side accessible?

 

[Bogo1229]

I agree with footer. Just because someone is a rigger does not make that person, no matter how much training they have had, capable of evaluating and able to give a load rating to a concrete ceiling. A general contractor could install the system, but you really should talk with an architectural engineer. They will be able to evaluate and rate your ceiling.

 

[SteveB]

Alternatively, you could gain a few inches by attaching Unistrut to the ceiling, and hanging your lights from that.

Gonna disagree with you on this one Derek. We have a black box full of Unistrut, installed decades ago for just this reason, gain height. To say we HATE this stuff, as an alternative to a 1-1/2" OD pipe grid with fixtures using c-clamps is a huge understatement.

- Students have a hard time understanding the importance of getting the nut turned just right so that it sits in the track correctly and it's really hard for the supervisor to see from below if the nut is seated correctly. Heck, even some of my Local 1 guys have trouble getting the nut installed correctly while holding up a 15lbs stage light tight to the track. It sucks !

- When mounted flush to the ceiling, the track is useless as an attachment point for safety cables and stage cabling (Unless the version installed has the holes on the side. Ours doesn't - it's flat steel). We had to purchase hundreds of 1/2" eye-bolts that have to get removed and re-installed adjacent to fixtures to allow a tie-off point for both. That all wastes time.

- There are at least 4 versions of channel steel I'm aware of, Uni-Strut, Versa-Bar, Kindorf, which is the most common used in the electrical contractors world, and the Home Depot version - Channel Strut ?. Actually, a WiKi search indicated other manufacturers I've never heard of, not to mention that Grainger and McMaster-Carr have house brands. In many cases, a hanger nut from one company will not fit another and it's easy to mix match as the nuts often look the same, or at least similar enough to allow confusion. Thus you usually HAVE to buy the nuts from one track supplier and you really, really need to pay attention to sticking to one supply to avoid the mix/match problems.

As example of the PITA using this stuff, my 8 steel dance lighting towers use Kindorf as the adjustable horizontal support for the fixtures in the tower. Kindorf/channel steel is actually a good use for this as you get a lot of flexibility of the position of the horizontal fixture strut, being that the structure allows both vertical adjustment as well as movement to allow for greater fixture depth. Hanging the fixture, is a PITA

Since the fixture pretty much points straight out of the open side of the tower (towards the stage), there's no need for a huge amount of L to R play in terms of fixture focus. The result is the fixture needs to be installed with the flat part of the yoke parallel to the Kindorf. When the fixture is tight to the Kindorf, it's really, really difficult to get your finger inside the channel to get the nut turned. The result is I just this summer installed studs to each hanging position so that the bolt can stay mounted to the frame, with the fixture hanging on the stud on a washer/hex nut. Much easier to get on/off.

Our current plan in the black box, is to either suspend a 1-1/2" pipe grid from the existing Unistrut grid, height be ****ed, or to totally remove the Uni-Strut and to install and use the hangers as attachment points for a pipe grid. Not sure which way the Dept. of Theater staff will go with this (it's their project) but they want the Unistrut crap out of their theater.

 

[venuetech]

Years ago the contractor for the borough pool, installed some of the air duct work with fasteners not certified for overhead use. 20+ years later that duct work came crashing down into the pool. Fortunately the pool was empty at the time. the ceiling was of a similar construction to your project.

what ever you use it must last the life of the building.

 

[Footer]

I remember having raceways with a sort of unistrut in it when I was in middle school. I remember it being a real pain to move fixtures.

However, if the OP is not going to be moving fixture often or never, it might be a decent way to go. As long as it is known that the space savings will mean longer labor/changover times.

 

[MPowers]

There are several different threads going on here all at once. I'll try to touch on them separately as it gets somewhat confusing and intertwined otherwise. Also, just a small point on semantics, when you say 40 gauge, I gather you mean Schedule 40 pipe.


The threads as I see them are:
1. Attaching a pipe to a ceiling.
2. Who can properly calculate the project.
3. Who can properly install the product.
4. Strut: Properties and types of accessories.

First, how to attach a pipe. The Clevis hanger posted earlier is all too often used for this but it is not rated for this purpose. It is designed to hold the weight of the pipe and it's contents in a static situation. A lighting pipe must be rigged to hold it's own weight plus at least 25# per foot of equipment, in a dynamic loading situation. Dynamic you say??? It's not moving, just hanging there! Every time a stagehand hangs or strikes a unit there is a changing load on the hanger, this does not take into account the forces imposed if a mover is hung on the pipe. The clevis hanger is relatively weak where the threaded rod goes through it. A rated pipe clamp, Pipe Clamps - Half Pipe & Full Pipe designed to hold rigged pipe with scenery or lights over peoples heads plus a rated bracket Automatic Devices Company designed to support the pipe and load from threaded rod should be used. The clevis bracket will allow the pipe to rotate or spin if units are side hung. A pipe clamp from a theatrical rigging company is designed to prevent this.

2. Who can calculate the project, strength of structure, necessary fastener strength, etc.? This requires a Structural Engineer. Many Competent Riggers can evaluate a situation and determine if an engineer is needed or not. If the Rigger is indeed Competent, they will advise an engineer be contacted about 80% of the time. There are situations where a Competent Rigger can make this decision, and in those situations he and/or his company (and their insurance carrier) become the responsible and liable parties for any work done under that contract.

3. Who can install the project. Any company who specializes in rigging installations and some General Contracting companies. Most General contractors will consult with a rigging company or subcontract to them, as rigging is what is known in the business as a "Specialty" trade. General contractors need very specific guidance when installing theatrical/entertainment industry rigging. It is little things like making sure there is clearance for the C clamp to fit on the pipe. On a recent job the contractor actually attached a conduit run to the pipe and had to remove it when we demonstrated the way a stage lighting instrument had to attach to the pipe. Stage rigging companies including the one I am employed by, install structural steel as well as winches , hoists, counterweight rigging and dead hung pipes and pipe grids. However, when we install structural components, we do so only with the stamped approval of a licensed structural engineer, specifying and approving the type and size of the structural members, the method of attachment and specific fasteners. On jobs out of state we have to make sure the engineers license is recognized in the state of the installation. Installing pipes in situations such as the original poster asked about are exactly what Certified Riggers do. When we install pipe grids, they are most often hung from rod, cable or chain that is attached to eyes, rods or brackets installed into concrete ceilings, precast beams or similar. Are we (Me) competent to calculate the loading and the fastener strength and type??? Absolutely Not! I can usually predict the type and size of fastener, but I will not spec them and guarantee the results. An educated guess, no mater how experienced is not a performance guarantee. If the owner/GC does not have a structural working on the project, we hire one. Once he calculates the load capability of the substrate (concrete, brick, etc.) in the direction we will be applying the load, he will often ask us for a fastener suggestion. This is because there are hundreds of fasteners and anchors for these applications, some are awkward to use for our applications, some are not cost effective for installation or expected life. Our experience as riggers has introduced us to a range of fasteners that are very suitable for the application. With our suggestion, he only has to do calculations on a small number of of fasteners to find the most suitable for the situation.

4. Strut. Strut is a universal product. There are many different brands. In addition to the ones mentioned, there are Uni-Strut (the father of all strut) B-Line, Cooper, G Strut, Power Strut, et.al. All strut of the same size, fits the same nuts, brackets etc for any brand. The various manufacturers go to a great deal of trouble to make sure they are interchangeable with the other brands. Otherwise no one would use theirs. I will often use strut from one brand and fittings from one or two others, depending on "off the shelf" availability at the time. The issue is that there many different sizes of strut channel. The most common is 1-5/8"x1-5/8" Unistrut Component Detail it comes in many variations but all are 1-5/8" across the open side. Other common sizes are 1-1/4" Unistrut Component Detail and 13/16" Unistrut Component Detail . All of the channel sizes come in many different configurations, back to back, double deep, side to side, side to back et.al. Unistrut Product Group .

For Lighting use, (I agree IMHO with the people who say it is inconvenient) However, there are many accessories to ease the pain such as the City Theatrical line. I have personally used their Track Tamer and like it a lot, but it is not cheap City Theatrical click on lighting accessories on the left hand menu, then click track tamers, to see Track Tamers. Also, someone mentioned putting a rod in the spring nut, to ease hanging, this is problematic and could be a potential danger as any slight twist of the instrument during focus can leave the rod loose and risk coming undone. However, there is a stud nut that does the same thing Unistrut Component Detail . Someone mentioned that the yoke did not move/pivot easy when almost in line with the strut. When hanging lights from strut (unless using a Track Tamer) there should be a square flat strut washer between the yoke and the strut channel. Unistrut Component Detail . I prefer a variation called a non rotating washer Unistrut Component Detail that is crimped on two sides to fit the strut slot and prevent rotation. This allows the use of a lock washer in rigging applications, creating a rated rigging attachment.

Hope this helps to clear a few things up.

 

[MPowers]

BTW, forgot to mention, in your area, Chicago that is, contact The Chicago Fly House WELCOME TO CHICAGO FLYHOUSE - REMARKABLE RIGGING . They are a very competent company and will help you with your project.

 

[SteveB]

4. Strut. Strut is a universal product. The various manufacturers go to a great deal of trouble to make sure they are interchangeable with the other brands. Otherwise no one would use theirs. I will often use strut from one brand and fittings from one or two others, depending on "off the shelf" availability at the time.

Hope this helps to clear a few things up.

Mike, great post, however.

Im my experience, there has developed over time, slight variations between manufacturers in terms of how their nuts fit the track and I can detail many examples of where a vintage Uni-Strut nut from 30 years ago, will not fit either Kindorf, or the HD Channels strut. Likewise that the HD Channel strut nuts, whose channels size is "supposed" to be the industry standard, will not fit a Kindorf strut, etc... I too was under the understanding that "it's all supposed to be one size" but in real life am finding this to not be the case, with the result that you go absolutely crazy trying to use anything new with anything old, or try to mix match brands. MY dance towers were built with Kindorf and I HAVE to go to the electrical supply house to get Kindorf nuts as I cannot use the HD brand. So goes the theory when it meets the real world and is one of the reasons I hate using channel steel as a replacement for a pipe grid setup.

SB

 

[MPowers]

Different strokes as they say. Strangely enough, Kindorf is one of the few strut brands I have never used, in fact I do not know of a dealer for that brand in this area. As an installer I only use new strut provided by my company so the issue of "old" parts not matching is not a problem. I simply have never encountered the problem you have. I don't doubt it exists, I've just been lucky. I avoid re using old strut when doing installs. If a client wants me to use existing strut for part of an install, I advise them that any warranty, written or implied, is only for the equipment, hardware and parts provided and installed by us. Attachments to building steel or structure are rated and guaranteed, attachments to structure added after the original construction by "others", i.e. strut et.al. are only covered in so much as the attachment method conforms to industry standard rigging practices or better. If the client (or project architect) brings in a structural to examine and certify the strength and condition of the structure, then we will use it and stand behind the install as a whole.

As to using strut to hang lights in any form, as I said, I dis-like that a lot and will generally advise against it. We design, engineer and install very good pipe grids and I would prefer pipe in almost any situation. There are exceptions. For example a recent installation in casino ball room I spec'd and installed strut for 8 FOH source-4's. Why? Aesthetics. They needed a wash and podium specials on the very front of the stage apron and there was simply no existing place to put the instruments. Solution, custom color, off white to match the ceiling, powder coated source fours. The Strut, track tamers, color frames and all the hardware were powder coated to match. The units will never be moved, focus will almost never change, only color and occasionally a pattern added, so the hassles of strut attachment is not an issue. The strut hangs about 2" below the suspended ceiling with the openings where the strut drops through the ceiling closed off with matching white bosses. The track tamers put the instruments about 3" +- closer to the strut than a C clamp to a pipe , so the entire installation is very compact and tight to the ceiling. The color coating makes them very unnoticeable until the room goes dark and they turn on, then the attention is to the stage.

 

[gafftaper]

To follow up on a minor point in the OP not discussed so far: Stability.

What about having that structural engineer/contractor attach 8x8 box truss to the ceiling instead schedule 40 pipe. It'll cost you an extra $700 in materials but the cost of the installation shouldn't change that much and you'll have something really stable to work with instead of a swinging pipe on a chain. In the high school I used to teach in I had a similar pipe installed in my little theater. It was welded together to make it solid. It was bolted to the wall and then was chained to threaded rod out in the middle. But it still was a little loose and kind of a pain to work with. I would have been much happier with some box truss.

 

[mstaylor]

In my area Kindorff and unistrutt are the only ones available. The nuts are interchangable but I prefer unistrut track but Kindorff nuts. I won't add anything to Mike's explanation, it pretty well covers it all.

 

[derekleffew]

Gonna disagree with you on this one Derek. We have a black box full of Unistrut, installed decades ago for just this reason, gain height. To say we HATE this stuff, as an alternative to a 1-1/2" OD pipe grid with fixtures using c-clamps is a huge understatement. ...

I never said I liked it; I just listed it as an alternative. Like many/most, I have a [-]love[/-]tolerate/hate relationship with this method of mounting fixtures. But sometimes the extra 5-7/8" of height and/or the aesthetics are more important than the extra labor involved.

...
- Students have a hard time understanding the importance of getting the nut turned just right so that it sits in the track correctly and it's really hard for the supervisor to see from below if the nut is seated correctly. Heck, even some of my Local 1 guys have trouble getting the nut installed correctly while holding up a 15lbs stage light tight to the track. It sucks !...

I bet you don't have a Strutster Spring Nut Insertion Tool, now do you? (Neither do I. I think it a rather silly tool, but I do appreciate its ingenuity.)

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[kendal69]

Like other have said you need peopel that are licensed as in contracting, engineering, rigging, and it all must be signed off bythe city along with the fire department. Sorry to always be the bearer of bad news but the minute you hang anything you better get the right peopel to do the work.

Here's n great example. I took the Rigging courese with HArry Donovam ( R.I.P. Harry ) and one of the last things we did was take a tour of the Cirque theatre. As we ran around every inch looking at rigging pints, rope, wire, shackles, etc. the head rigger taold us how he conducts business. He brings in the manufacturers of all the equipment he uses, yes the actual manufacturers and shows them how he is using their equipment and mekes them sign off of it viability. Even the rope manufactures and his insurance carrier and his upper management, city, state, fire and safety officials. EVERYONE is involved.

The ropes he uses are used for just so many uses ( per mafgs recomendations ) then they are cut up and thrown away so no one will ever use the equipment and be unsafe.

I learned more for the hear rigger at Circque on how he conducts business than anyone I have ever dealt with. Any time we all hang a light, truss, prop, plug, wire, drape etc. We need to be 110% sure that things are safe because people lives depend on what all of us do.

Remember it not just hang it and leave it ( anything ) it all must be inspected on a regular basis. Everything sounds simple till things go sideways.