Metal roof walkways are quickly gaining popularity
Metal roof walkways are quickly gaining popularity due to their ability to provide a stable and safe work area for maintenance personnel while extending the life of the roof itself. These systems can easily be fitted with hand-rail to provide fall protection. While the process of quoting, ordering and installing may seem daunting, the steps are actually quite simple and can add tremendous long-term value to any building project.
A well-designed metal roof walkway should complement the workflow of rooftop service personnel. Seasoned metal roof walkway providers should be able to evaluate a roof plan and make suitable recommendations with respect to layout.
The overall plan should consider the following:
• The number of planks required?
• How many directional changes are necessary?
• Will the walkway cross a ridge- if so, how many times?
• Is pitch correction necessary?
• Will a handrail or toe board be necessary- if so, will it be used on one or both sides of the walkway?
Necessary materials
When a job is bidding, we all know that detailed roof plans are not always available. Fortunately, with a few basic inputs it is not overly difficult to provide a good working budget for a walkway system. This is achieved by making some high-level assumptions about the project and then using a general price-per lineal foot rate. The first and most significant cost is assessing the amount of planking material needed. Systems generally employ 24- or 36-inch widths. Occasionally a walkway may be specified in greater widths where a platform is required.
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Most walkway systems use 18-gauge galvanized steel safety grating with pierced surfaces to provide a high level of traction. Typical grating planks are constructed in 12-inch widths designed to interlock with each other, and are fabricated so they provide sufficient rigidity when supported by roof seams or by fabricated supports. Occasionally a heavier gauge plank is necessary where a higher load rating or a higher-than-normal span between supports is required.
Accessories to secure the planks to the metal roof include “M” clips, fasteners, support plates, hold-down clamps for standing seam roofs, or fasteners for rib roofs. Ledgers are used to ensure that planks are in the same plane where directional changes occur, so as not to introduce a tripping hazard.
While many metal roof walkways are not pitch corrected, some high-pitch roof systems do require pitch correction. This is generally accomplished with a series of sub frames and supports that result in a level walking or working surface. Costs for pitch correction vary based on the roof pitch and whether just the parallel (to the ribs or seams) planks are pitch corrected, or the entire walkway system is pitch corrected.
Ensuring safety
Various regulations and codes, including OSHA 1910.23 and IBC 1607.7, dictate the use of safety rails and toe boards. Fortunately, these are easily adapted to metal roof walkways. Safety rails are usually supplied for the down slope side of the walkway system. Situations where handrail is used on both sides of the walkway include sections that run along the ridge, or parallel sections on high pitched roofs. Toe boards are required when there is an exposure below to falling materials. Handrails must be capable of withstanding a load of at least 200 pounds applied in any direction at any point on the rail. Some states have requirements exceeding this value so it’s important to check the local code. If the handrail is constructed of metal pipe-which is common with metal roof applications-material must be at least 1 1/2 inches in diameter and the spacing of support brackets cannot exceed 8 feet. A standard railing consists of top rail, intermediate rail and posts with a minimum vertical height of 42 inches from the upper surface of top rail to the platform level.
Contractors procuring metal roof walkways should consider that it is important to not only secure high quality materials, but to take into account the value of a supplier that supports the process. Does the supplier provide all the necessary accessories, detailed roof plans and bills of material showing plank, clip, and accessory placement on a job by job basis? Does the supplier provide assistance before, during and after the job? The right combination leads to a high-quality installation that is on time and on budget.
Eric McClung is president of Newbury Park, Calif.-based R&S Manufacturing and Sales. To learn more, visit www.RnSsales.com.
