Metal Railing Installation

Modern metal railings combine style, safety and sophistication with quality and durability. Metal railings prevent falls and unauthorized access to certain areas, and are required when a building has steps, landings, platforms or accessible roof spaces. Applications range from stadiums and museums to businesses and residential homes.

Correct installation ensures metal railing safety

By Mark Robins
Photo courtesy of Trex Commercial Products

Railings in a commercial setting must be strong enough in both the visible portion above the finished floor, but equally (or more) importantly, need to have solid support below the floor or within the walls at attachment points. Christopher Costanza, RA, AIA, LEED AP, architect at 9X30 Design Architecture LLP, Rochester, N.Y., says consider the following example of an outdoor deck at a roof-top restaurant. “The railing has the potential to have a 220-plus pound person leaning against it every 20 linear inches. Multiply that lateral load by the leverage created with a 42-inchhigh guardrail, and you start to understand that the attachment mechanisms of the railing are critical to the design. As these loads are transferred from top rail to posts to base plates, it becomes challenging to design aesthetic railings within the usual construction budgets. Metal, to my knowledge, is the best-suited material.”


Installation methods vary depending on the style of the building and how it’s framed. Given what he’s learned about water penetration, Seth J. MacGillivray, president of American Railworks, Lynnwood, Wash., says most railing systems are fascia-mounted to avoid penetrating the siding or the top of decks. “For the American Railworks product, railings are built in as large panels as possible so that field installation has minimum moving parts,” he says. “For instance, if a stair run is 18 feet, the stair panel will be built to fit the stair in one panel, rather than attaching loose posts or plates in the field. This makes the system more stable for the long term and brings down labor costs. Mounting attachments are typically galvanized or stainless steel lag bolts. We prefer galvanized because it limits the bi-metallic reaction between the two metals (aluminum for the railings and galvanized for the lag bolts), but many architects still prefer stainless steel lags.”

Photo courtesy of American Railworks

What is behind walls for support/attachment of metal railings? MacGillivray says for fasciamount railings, his company has engineered its product to require a minimum of 3 inches of structural embed, which is typically pressuretreated lumber. “Four, 3/8-inch lag bolts per post is the most common mounting method,” he adds. Costanza says depending on the construction type, the solid blocking within walls could be wood, metal or concrete.

MacGillivray cites the most important component of his company’s metal railing systems to be the lateral and point loading of the railings. All of his systems are designed and fabricated to withstand or exceed the 200-pound point load and 50 pound/ linear foot lateral load requirements. Built into this system is the method of attachment, which is typically a four-lag bolt fascia-mounted plate.

Andrew Miller, president of Dakota Safety, Saint Paul, Minn., stresses that an engineering analysis by the railing manufacturer should be done to make sure the attachment method allows the railing system to meet performance requirements. This would include an analysis of the sub-structure and the attachment process via either welding or mechanically attaching (like masonry anchors). “Ballasted railing systems for general industry applications have that analysis worked into the system because they are tested as a free-standing system mainly used for fall protection,” he adds.

Codes and Safety

The International Building Code (IBC) and the Occupational Safety and Health Administration (OSHA) have codes that must be met when installing metal railings. Costanza says the IBC is his starting source for railing information and that it describes basic rules and refers to other codes such as ANSI or ASCE for additional detail. He also cites the Internet as a useful tool for gaining information, but cautions that reading a contractor’s opinion online, “is not the same as following the letter and intent of the current building codes.”

Photo courtesy of Dakota Safety

Miller contends the key to providing a safe atmosphere within a building is following the standards set by both IBC and OSHA. “That way any individual, whether it is someone who is visiting or someone who is working inside a business-owned property, will be in a safe environment,” he adds. “One of the key areas where the IBC and OSHA crossover is in fall protection and building guardrail requirements. Providing safety precautions in both areas can help companies make sure they’re following all the proper procedures and avoiding any potential tragic accidents.”

Miller says for metal guardrails to be up to code, they must be at least 42 inches above the ground level space. For the building roof areas, he says the IBC requires a guardrail to be in place, unless there is some other sort of fall protection system installed. He further explains, “OSHA doesn’t dictate quality control for guardrails or installation criteria, but it does state that any employee working on the roof of your building must be protected from falling with a quality protection system.”

Even strictly following codes, installation mistakes can still occur during installation. MacGillivray witnesses the most common mistake to be waterproofing. “Our panelized systems make installation fairly simple, and once the system is designed and engineered, installers just need to use the lag bolts the engineer has required,” he says. “What typically gets missed though is the coordination between the builder and the railings installer on what waterproofing methods are necessary. The best way to avoid this is for railing installation companies to work with a building envelope engineer on best practices for waterproofing, and set those as a standard for all installation projects.”

As a designer, Costanza sees many types of metal railing mistakes in the field, but cites the most prevalent mistake he sees is handrail detailing. “I’ve seen too many handrails with diameters too small or handrails with improper supports that prevent continuous graspability,” he says.

Miller cites metal railing systems installed on roofs for fall protection that have not been sufficiently sealed to be a huge issue because of their leaks. Furthermore, for safety, code compliance and correct installation, he stresses attaining a full understanding of a metal railing’s application and how it will be used citing:

• Is it used by just maintenance personnel or by the general public?

• What areas are being protected and how the railing be placed to protect those areas?

• What types of surfaces are involved?

Aesthetics and Effectiveness

More and more, a metal railing is not just being recognized for support and safety via its strength and stability, it is gaining acceptance for its aesthetics. “Its versatility and ability enhances any setting aesthetically,” says the team at Trex Commercial Products, Minneapolis. “Thanks to the level of customization available, metal railings can offer modern and sleek styling for contemporary projects, as well as traditional and intricate designs for more formal installations. When selecting railing, ensure that it matches the design of the project, and carefully consider the infill material. Glass panels can add lightness and visibility, while other materials, such as metal mesh or cable, can create a more industrial look. The right combination of metal railing and infill material will provide a safe, secure railing, while also enhancing the aesthetics of the space.”

Claiming “it’s all in the design,” MacGillivray says mounting methods are fairly easily duplicated from project to project, so how the posts interact with the top rail and bottom channel, the type of infill panel between posts, and railing color all take a standard railing that could be an afterthought, and make it into a design feature of the building. “Little details like using caps on the lags or painting the lags are also details that can set you apart from your competitors,” he adds. “Work with a good designer who has been in the industry for awhile. They’ll not only be able to instruct you on design and engineering, but also on best practices for waterproofing, installation and final touches.”

Photo courtesy of Trex Commercial Products