From the July, 2014 Issue of Cabling Installation & Maintenance Magazine
A social-media question about which option to use for cable conveyance affirms that both have their time and place.
Recently I initiated an online exchange about the cost-effectiveness of using cable tray for cable conveyance versus using non-continuous support systems like J-hooks. The discussion, held in a LinkedIn group, was prompted by an inquiry from a reader of this magazine who was looking for any hard numbers or other available information specifically related to the costs associated with either option. This individual, a system-design professional, has been getting conflicting information from the installation contractors with whom he interacts. Cost-comparison data that is readily available was produced by organizations that provide one type of product or the other, so predictably the economic breakdowns contained therein favor the respective organizations' offerings.
In an effort not just to assist one individual but also to provide a broader perspective on the choices that user organizations are making every day, I posted the tray-versus-hook premise as a discussion item in this magazine's LinkedIn group. This article includes opinions and experiences shared in that discussion, as well as information obtained in a more-in-depth conversation with one of the discussion's contributors, who is an employee of a company that offers hooks and other non-continuous support systems. This article may not be the definitive statement on whether it's trays or hooks that are most cost-effective. But hopefully it will provide a glimpse into real-world use cases and some of the challenges regularly faced at cabling-installation sites.
Various scenarios
In my discussion post, I specifically requested, "In addition to dollars-and-cents comparisons, I'm hoping to get thoughts on 'In Situation X I go with hooks and in Situation Y I go with tray.'" Several of the responses carried a theme of preferring to use tray where and when it is practical. "When I hear we're going to be installing tray on a particular project, I get a sense of a forward-thinking customer that values the importance of their cabling infrastructure," said John Collesidis, RCDD, project manager with Com-Bell Systems (www.combellsystems.com). "When we get started on the tray installation, however, there are more obstacles, hits, elevation changes that require so much tray modification or interruptions-or inaccessible ceiling spaces-I wonder if anyone else in the planning stages knew that tray was going to be used."
William B. Buckingham, RCDD, an independent information technology systems (ITS) consultant, added, "In many applications I have found that cable tray has been proven to be more cost-effective than J-hooks for major cable pathways. In addition, the cable tray is more cable-friendly with less crush damage that happens with large bundles on J-hooks, and [the tray is] easier for the additional cable installation in the future. Some cable manufacturers strongly suggest that cable counts over a certain number be supported by cable tray, to ensure performance.
"The challenge will be the environment in the ceiling. If you are able to get involved in the building design, you can fight for that space in the ceiling for the tray placement. Very often the construction has started without the benefit of cable-infrastructure design, or there is existing ceiling space with challenges that limit your options. Sometimes in this case a flexible tray like SnakeTray (www.snaketray.com) can be used, which is still considered cable-friendly. J-hooks work best for the runs from cable tray to work-area or device locations."
Complement or compete?
The idea that trays and hooks are used as complements to each other was reinforced by Brett Diaz, owner of Dynamic Tele/Net Infrastructure Inc. (www.dtiincorporated.com), who offered the following insight from his experience: "J-hooks-mostly used above ceilings where they won't be seen, and used in smaller cable-run applications. They are a great way of supporting Category 5e, 6 and fiber cabling. Inexpensive compared to cable tray and will install much quicker. Small clients that are always looking for a cheaper solution will pay for this quicker than for a tray." He emphasized that on smaller jobs, end-user customers often do not concern themselves with the specifics of the products or systems used to provide cable support, and look simply at its cost. On these projects, specifying a system that likely is the best long-term solution and costs more than other options puts a contractor at significant risk of losing the bid based entirely on cost.
"Tray-will be used for data center work or in a design given from an architect, or that has been 'speced' from a design firm or RCDD. Mostly used when large amounts of copper or fiber cabling will be installed." For a client with budget flexibility, Diaz said, he offers multiple options in an estimate for the client to choose from. "If their IT folks are involved, it usually becomes a discussion. Some customers like trays in open ceilings because it provides a neat appearance."
On most installations, he concluded, "these items will be used hand-in-hand. Cable always needs to have support. When we run or install tray, it will house the bulk of the cable run. And as we branch out from the main tray run, we use J-hooks for the support of the cable to its drop location. Add a service loop of no more than 10 feet and you're done."
Don't knock non-continuous
Sounds simple, right? Sometimes it is and sometimes it isn't. David Landphair, RCDD is a regional sales manager for ERICO's (www.erico.com) CADDY datacom and telecom products, which include non-continuous support systems such as the hooks discussed in this conversation. Landphair contributed technical information to the LinkedIn discussion and agreed to a more-in-depth interview with Cabling Installation & Maintenance. He explained that as an organization, ERICO is "a very strong supporter of codes and standards," and that with respect to cable support, he and the company "look at it from a safety perspective as well as a performance perspective." As such, he further stated, "From a performance perspective, there is no difference in quality between cable trays and J-hooks, as long as they are installed properly, offer the correct bend-radius performance, and meet other standards as well." Trays, he pointed out, are not immune from bend-radius violations, particularly when "waterfall"-type branches are employed.
Furthermore, Landphair said, the fact that even a cabling system's permanent link does not necessarily always live up to its name is worthy of consideration. Not all installed horizontal cabling remains in place forever, and the options for using cable tray or non-continuous supports can affect the manageability of moves/adds/changes (MACs) as well as the removal of abandoned cable. His primary point was that the relative ease of removing cable from a hook-based support system-whether to accommodate a MAC or to remove it permanently-is noteworthy.
Finally, Landphair noted that particularly in environments outside of a data center, many of a network's endpoints require few, not many, cables. Many installers and end-users alike in commercial-office-type corporate networks have noticed a trend toward fewer cables being brought to each workstation. Coinciding with that is the addition of other devices to the IP network, such as wireless access points, security cameras, lighting, and distributed antennas. This scenario of more networked endpoints, each requiring few cables, sets up nicely for non-continuous support systems, Landphair emphasized.
Michael Brownholtz, a senior systems specialist with Bala Engineers (www.bala.com), weighed in on cost-benefit considerations as well: "Keep in mind that the cost of installing cable tray has to be justifiable," he advised. "I would use cable tray when and where it's required. If I were designing a system that called for a great deal of cables going in a specific direction or directions, then cable tray would be the way to go, until the quantity of cables wouldn't warrant its use. Then J-hooks would be the next choice. I would use J-hooks where the quantity of cable doesn't justify the use of cable tray."
The real world
As the LinkedIn discussion brought home, these support systems are not installed in a vacuum but rather in real-world environments. They also are installed under real-world scenarios, as was poignantly noted by Tom Pettit, owner of Campbell, CA-based TNT Communications. Pettit relayed the following story in response to the "tray-versus-hook" question posed in the forum.
"When estimating a recent job in Silicon Valley, to rewire the second floor of a building, I pushed up tiles to see what was there. I found J-hooks everywhere with cables all tie-wrapped to them. I knew it was going to be a job to get the old cable out, so I added an extra $3,000 to my estimate just for removal. I had my guys also take out the J-hooks because there were so many of them, and they were in the way to pull our new cable.
"As with any job, the customer was in a time crunch. We got the call Good Friday afternoon, I put a crew of five together, and we started on Saturday morning. We worked straight through until Monday morning and finished all the cable pulls. We pulled 8.5 miles of cable that weekend. Instead of using all those J-hooks, I used some trays in the long runs and a few J-hooks where needed. I feel that this-along with a lot of coffee-helped the job go faster.
"We removed 8 pickup-truck loads of cable, and also recycled 12, 5-gallon buckets of hooks. So I charged $3,000 for the cable removal, and the amount I got for the recycled cable and hooks was $3,825. With that money, I gave my crew each a bonus and we had a night out for the crew and their families at Dave & Buster's. It was my way of showing thanks for a job well done."
He began his story by stating, "A couple years ago I would have said J-hooks are the way to go," and ended his story with, "Trays are now on the top of my list when I do an estimate." For many users and installers, though, a hybrid management system that combines the two is common. That was, in fact, the approach Pettit took during his Easter-weekend install.
Patrick McLaughlin is our chief editor.
Getting 'hooked' not a global trend
The social-media dialogue that serves as the basis for this article included an observation by Gert Molkens, co-owner of Husaflex (www.husaflex.be) a Belgian firm specializing in security systems over IP. Molkens' comments included, "I don't see many J-hooks in Belgium. I'm afraid that most cable is just thrown onto the ceiling tiles, unfortunately. When I first ordered J-hooks a couple years ago, our distributor had never sold them before."
Later in the conversation, Molkens asked, "How do you fix the J-hooks? Do you attach them to the concrete ceiling, or do you use clips that fix them to the supporting structure of the ceiling tiles?"
To that question, William B. Buckingham, RCDD replied, "Do not attach to the support structure wires of the ceiling tiles. Properly anchor the threaded rod or wire for the J-hooks into concrete or building structure. Clamps and clips work well for attaching to the 'i' beams. The cost for properly anchoring J-hook wires and rods when dealing with large-cable-count pathways could be equal to or more than the rods for cable tray installation."
In the U.S., NEC 300.11 addresses the issue, as ERICO's Landphair noted. -P.M.