BENEFITS OF ONSITE FABRICATION OF WIRE MESH CABLE TRAY FITTINGS

Back to Blog Listing

BENEFITS OF ONSITE FABRICATION OF WIRE MESH CABLE TRAY FITTINGS

It is well established that wire mesh cable tray saves considerable installation time and labour cost when compared to conduit. Wire mesh requires fewer parts, no preformed fittings and fewer tools. Even more significant is the ease of creating wire mesh fittings on site, which gives complete freedom in routing combined with exceptionally fast installation. 

Because wire mesh is highly configurable in the field, it does not require specially fabricated components to make corners, T’s, up/ down angles or intersections. Installers simply cut the mesh to any desired configuration. Further, these installation steps do not require as high a degree of training as the “art” of conduit bending.

Wire mesh requires fewer parts, no pre-formed fittings & fewer tools

OFFSITE VS. ONSITE FABRICATION

Although prefabricated fittings for wire mesh tray are available, they do not usually provide a productivity benefit – and they can actually slow the progress of a job. That’s because prefabricated fittings can cause the contractor to lose onsite flexibility. Electrical professionals are often the first trade to lose dedicated space due to changes in configuration. Sewer, sprinkler and HVAC are given priority over electrical services, and electrical is expected to work around them. The location of these obstacles frequently differs from what is shown on the original drawings.

Wire mesh tray is uniquely suited to working around obstacles in the field. Standard lengths of tray can be cut and bent to create any bend, sweep or level. On the other hand, the contractor who orders prefabricated fittings based on the drawings may well arrive onsite to find that the fittings do not match real-world conditions and new ones will need to be ordered.

In order to change direction using a prefabricated fitting, the installer must cut a section of installed tray because the straight tray rarely stops exactly where the fitting is needed. This process requires cutting through the entire tray, locating the correct fitting, bolting it in place and attaching another section of straight tray. In contrast, field fabrication requires that only a portion of the tray section be cut, bent and bolted to make the appropriate changes now. 

Onsite fabrication means no downtime waiting for additional components. If additional tray lengths are required, they can be ordered from the distributor for immediate delivery, while the right size prefabricated component may not be in stock. The contractor benefits from ready access to stock items versus made-to-order components.

COST CONSIDERATIONS

Contractors gain financial advantages due to the fact that components can be easily fabricated onsite. Contractors are well aware that installed runs of straight sections of tray have pathway interference issues as often as every 20 feet. As a result, tray must be cut to length in nearly every instance where a fitting will be installed. There is almost never the opportunity to “simply bolt on” a factory-fabricated fitting without first cutting a straight length of tray. This is where the advantage of field-fabricated fittings truly shines: By the time the tray is cut to length, most of the labour is already completed. The sample bill of materials shown to the right demonstrates the labour savings associated with field-fabrication fittings compared to factory-made fittings. Higher labour units required to install factory-fabricated fittings (highlighted) translated into 29% more time for the total installation

CONCLUSIONS

Wire mesh is a unique cable management system due to its inherent cost-saving potential, including the ability to create fittings in the field. This approach is shown to be faster than using factory fabricated fittings that require cutting the tray completely and bolting on a fitting, compared with a partial cut to the tray to create the exact fitting required. This ability to create fittings onsite, rather than ordering manufactured fittings, is an important consideration for electrical contractors looking for ways to save time and reduce cost. Industry standard cost comparisons confirm that field-fabricated fittings require less time and labour to install. Further, wire mesh tray is also designed so that field modifications do not compromise UL classification.

DP Building Systems are a distributor of Legrand and Cablofil, if you require any information or support please contact DP Building Systems technical team on 0121 706 7777 or technical@dpbuildingsystems.co.uk