How to Build Metal Stairs for Commercial & Industrial Spaces
Depending on the location, use, and application, the proper design for these metal stairs can vary greatly. Beyond legal regulations and practical concerns, experts advise various best practices that any business should take into account. Here are a few factors to consider when planning out a stair system in a commercial setting.
Does OSHA or IBC apply? Where are the stairs located?
One of the first questions to answer when designing a commercial staircase is ascertaining, which set of rules apply. In addition to municipal and state building codes which will govern any structure in the area, there are also broader guidelines that govern commercial applications specifically.
The federal agency which oversees workplace standards, and therefore stairs in a workplace setting, is the Occupational Safety and Health Administration (OSHA). OSHA broadly overseeing workplace practices and ensures that the physical space within a workplace and the practices within are safe for employees and contractors. Their guidelines will typically govern any commercial space that workers may access.
OSHA vs. IBC
In contrast to OSHA regulations are the International Building Code (IBC) standards. IBC standards are generally more stringent than OSHA regulations because they apply beyond the workplace environment. Whereas OSHA standards apply to areas where trained and informed workers venture, IBC standards are for any space in a commercial property. Thus, they govern structures that customers or members of the general public will access.
As you have probably surmised, the two standards are not mutually exclusive, and there is extensive overlap within the individual codes. However, it is still crucial to know which codes apply. As a general rule, if only employees and workers can access a set of stairs, it must comply only with local building codes and OSHA guidelines. If the general public can access a staircase, they need to stay in line with local building codes, OSHA, and IBC.
Which material should you use?
In residential contexts, there are numerous materials and finishes available for stairs. The options are less broad in commercial applications. For reasons of strength and fire prevention, you could see metal stairs in almost all configurations made for commercial and industrial applications. Generally, this will entail steel construction due to its high strength, comparatively low cost, and resistance to fire. In certain contexts where weight is a concern, aluminum is the best option. However, in either case, commercial stairs will rarely be wooden, as these are inflammable and easily worn out through time.
Angle of Staircases
Another factor to consider when planning and building a staircase for a commercial application is the angle or type of stairs. OSHA governs the maximum angle that a commercial staircase can traverse, comparing its vertical rise to the horizontal distance it covers. For ramps, OSHA dictates that the angle must be less than 30 degrees. For a standard set of stairs (i.e., not a ladder or other alternative stair type), the angle must be between 30 and 60 degrees. Further, the stair system must incorporate a landing at the top and bottom of the stairs. For scenarios where the top of the landing leads to a door, OSHA dictates that a distance of at least 22 inches must exist between the end of the fully opened door and the top edge of the landing.
The maximum allowed angle is a factor where IBC regulations are more stringent than comparable OSHA rules. This makes sense, given the likelihood that elderly or lesser-abled individuals will be required to traverse the stairs. As such, the maximum angle allowed for IBC compliance dictates a 7-inch rise over an 11-inch run. This equates to about 30 degrees.
A logical first instinct might simply make a commercial space both OSHA and IBC compliant, given that design differences may seem minor. It should be noted, however, that an IBC compliant staircase, while easier to traverse, also consumes much more space. In the context of a warehouse or other space-intensive area, this additional required real estate may be a considerable detriment.
What is the Best Step Height and Depth?
Average stair height is one of the largest contributors to how difficult they are to climb or descend. For OSHA compliance, each step should be no taller than 8 inches, with 9.5-inch tread depth. This results in a fairly steep step which some may find difficult to climb. Especially when carrying heavy objects or otherwise burdened. Because of this, it is important to remember that the OSHA and IBC codes are established as limits, not necessarily recommendations. A shallower step may be the better choice for your commercial space.
In keeping with the established pattern, the IBC stair height requirement is more accommodating to lesser-abled individuals. For IBC compliance, each step can rise no more than 7 inches, provided an 11-inch tread depth. Further, while OSHA does not regulate the backing plate of each step, IBC requires that the back of the step have no more than a 4-inch gap.
Width of Metal Stairs
Another factor to consider regarding stairs dimensions, and another place where IBC and OSHA requirements vary, is how wide the stairs must be. At a minimum, OSHA requires stairs to be a relatively narrow 22 inches. For practical reasons, many applications will dictate choosing a large staircase, but in no case can one be more restricted than 22 inches.
In keeping with the stricter requirements of the IBC, publicly assessable stairs must be a minimum of 36 inches wide. There are some exceptions to this. For example, if a publicly accessible staircase will experience fewer than fifty people a day, then you could use a narrower stair. However, in all but the rarest instances, 36 inches is the IBC minimum.
What Rules Apply to Handrails?
The handrail requirements for OSHA are relatively minor. On open sides of stairwells, OSHA requires railings and a 34-inch high handrail on at least one side of the staircase. Due to the majority of the population being right-handed, the recommendation is that, if only one handrail is present, the right side placement is preferred as if one were descending the stairs. Because children are unlikely to be present in a commercial non-publically accessible area, the handrailing does not need to be continuous but may not have any significant breaks.
The IBC has similar but slightly more comprehensive regulations for hand-rails. Handrails must be present on both sides of the staircase, and they must be at 34 inches from the ground. Due to the likely presence of children, the handrail must be continuous with no breaks for IBC compliance.
In both cases, a recommended diameter for a safe handrail is between 4 and 5 centimeters, which both standards agree is an optimal size for ease of gripping.
Visibility is Crucial
Staircase visibility is an often-overlooked aspect when looking at how to build stairs. This is likely because, while many guidelines are provided, there is little firm regulation over the matter. However, ensuring proper visibility in and around a commercial staircase is crucial to ensure safety and avoid injury. There are several best practices to employ when planning stair covering options and surrounding design.
Make the Step Edge Contrast the Step Itself
One of the most common causes of stair related accidents is when individuals misjudge where a step ends. And therefore, trip on the edge of the tread. An excellent way to avoid this is to make the leading edge of the step contrast with the rest of the step. Making it easier to judge where the step begins and ends. Your first idea may be to make the step edge a different color. But this is actually not the most efficient way to think about the problem. Especially in low-light conditions, contrasting colors may appear very similar is they share the same lightness (in other words, their light reflectance value).
Light vs. Dark Colors
Thus, to achieve the most contrast, you want to pair light and dark colors. This high lightness contrast will make the difference apparent, even in sub-optimal lighting or for those with color-perception difficulties. This is also an area where looking into applying a non-slip surface can increase the safety of your stairs. Many companies offer rubberized or textured non-slip coatings in high-contrast colors, which provide increased visibility and traction with one product. This is an especially good practice in areas that may experience wet floors.
Perhaps the most important – and cost-effective – way to provide a safe and easy to traverse stair design is to make sure the lighting is adequate. The lighting level is measured by the “lux” of the area. This is a measurement defined as one lumen per square meter. Both sanctioning bodies recommend at least 100 lux, as measured at the tread of each step.
Beyond the sheer amount of lighting, the evenness of the illumination is very important. While putting a single dominant light above a staircase may provide a considerable quantity of light, the way in which the light is spread can actually lead to more hazards. When a staircase is illuminated using a powerful single-point source, dramatic shadows can be created by the uneven light distribution. This can make visualizing the edges of the stairs difficult and may even counteract the contrasting color scheme mentioned earlier.
The best method of lighting is to have multiple lower-wattage light sources to cast an even and sufficient light over the entire area. Beyond this, it is commonly recommended to add lighting to the steps themselves. This will depend greatly upon the specific application. In a situation where the stairs will often be used in poor light conditions, such as at night or in a light-controlled environment, providing a lighted strip to the edge of the step will ensure that the stairs can be used safely. Alternatively, a simple, downward-facing accent light affixed to the side of the riser can achieve the same result.
Custom Construction or Manufactured
Clearly, compliance with OSHA and/or IBC can become a somewhat complicated process. Not only is it a matter of ensuring that the applicable codes are met, but there are design practices beyond those codes which it is crucial to follow. Given this complexity, many companies forgo the complication and uncertainty of designing their own stair solution. Instead, they outsource their stairs planning to a dedicated company. This choice, while not required, has many advantages.
Experts know the code already
The largest advantage of purchasing pre-made stairs from a dedicated supplier is that they will already have set designs. More likely, their products comply with the applicable requirements. Rather than you or your architect having to spend time and effort researching questions such as “how many steps require a handrail?” or “what are safe step shoes?”, you can simply explain the application to the stair company, and they will provide you with the proper design.
Speed and upfront pricing is important in the construction
The lesser time needed in production is another key advantage of metal stairs. Given the steel construction of most commercial stairs, sourcing the materials, fabrication, welding, and transportation for the stairs can be a tedious process. By choosing a reputable supplier, all of these logistical hurdles will already be solved in a timely manner.
Manufactured stairs also have the distinct advantage of upfront pricing, which simplifies numerous aspects of the planning and building process. By choosing an all-in-one stair solution, dozens of line-items can be compressed into one.
Don’t overlook the details
Given the vast scale and complexity of most commercial construction jobs, choosing the proper type of stairs may seem like an insignificant detail. Yet, one of the largest sources of lawsuits or workplace injury is people falling downstairs. So, it is a detail worth focusing upon. Unsafe or overly steep stairs can not only hurt efficiency for a company. But they can also be a source of liability or code violation. Luckily, the applicable standards are relatively straightforward and well documented. Thus, when planning a project, being mindful of which regulations apply is helpful. Getting these recommendations right will avoid problems in the future.