Posted by Stephanie on April 24, 2023
Guard rails are necessary to keep fall incidents at bay in the construction industry. However, they need to be built in a manner that adheres to the Occupational Safety and Health Administration (OSHA) standards for guard rails. These standards are strict and precise to ensure that the workplace is safe for any personnel who work there.
Having the right guard rails at your construction site is necessary even if you believe that workers will stay away from the edge of a platform. The OSHA guidelines aren’t solely designed to provide employees who are on upper levels with protection. They are also meant to protect property, workers, and pedestrians on the ground.
Once you’ve built guard rails for your construction site, make sure that they’re able to withstand a person’s weight and prevent them from falling. If a guard rail is ever broken or damaged, it needs to be repaired immediately. Here’s a comprehensive guide on guard rail systems and the specifications they must be set to before you have them installed.
The Importance of Guard Rail Systems in Construction
Guard rails are barriers that are commonly used on roads and highways but have also become standard at construction sites. This type of structure is comprised of sturdy materials that are meant to protect workers instead of requiring them to receive training for using and wearing fall protection systems.
These rails are usually made with corrugated steel and are bolted down or concreted to the ground to make sure that they’re unable to move with human force. While these structures can be damaged by heavy machinery, this issue is rare. If your construction site didn’t have guard rails, employees would have a higher risk of falling and being injured while at work.
Worker Fatalities Caused by Falls
When employees are tasked with working near unguarded openings, stairs, edges, or sloped roofs, OSHA requires employers to provide these individuals with protection with the use of guard rails and any necessary accessories.
In the construction industry, the primary cause of worker fatalities is falling from a higher level. From 2006-2010, more than 1,000 workers died every year in this industry. Around 35% of these deaths were caused by falling from a height. Over 125 of the 1,000 workers died every year by falling from roof edges that didn’t consist of guard rails. Similar falls occurred through skylights and floor holes.
All of these issues can be prevented with guard rails that are either customized to your specifications or pre-built. In 2020, over 350 of the 1,008 deaths that occurred in the construction industry were caused by falls.
OSHA maintains an extensive set of regulations and guidelines that are designed to keep construction workers safe with properly placed guard rails. Whether you’re working on a roof or platform, OSHA has guidelines in place that apply to any workers who are going to be exposed to drops of at least six feet. In this scenario, employers will need to provide ample fall protection in the form of:
- Placing safety nets in the vicinity
- Providing each employee with fall arrest systems
- Installing guard rails in any hazard area
In many situations, the location and type of work that’s being performed will determine what kind of fall protection is necessary. When the employer selects a guard rail system, they will need to adhere to the following rules and regulations:
- The uppermost edge height of top rails needs to be 39-45 inches higher than the working or walking level. Exceptions are in place when site conditions don’t allow it and certain criteria are met. For instance, if employees use stilts, the uppermost edge height for the top rail needs to increase at an amount that’s equal to the stilt height.
- Screens, mesh, mid-rails, or intermediate vertical members need to be installed between the working surface and top edge if there isn’t a wall that’s above 20 inches.
- If you install mid-rails, they should be placed around midway between the working level and highest edge of the guard rail.
- Mesh and screens need to be positioned from the working level to the top rail. They should also be extended along the opening between any rail supports.
- Balusters and other intermediate members that are placed between posts can’t be 20 or more inches apart.
- Guard rail systems need to be able to withstand 200 or more pounds of force in two seconds along the top edge and at all points of the edge. When this force is applied, the rail’s top edge can’t deflect downward to the point that it’s below 39 inches higher than the working level.
- Any mesh, screens, intermediate members, and mid-rails that are installed in the area should withstand 150 pounds or more of force.
- Guard rails can’t consist of jagged or rough surfaces that might cause lacerations or punctures when a worker falls on them.
- Mid-rails and top rails can’t overhang terminal posts, which would result in a projection hazard.
Types of Guard Rail Systems
There are three primary types of guard rail systems that you can install at your construction site or in your facility. These systems include:
- Job-built guard rails
- Commercially available systems
- Temporary guard rails
Job-built guard rails are usually made from wood and are constructed from start to finish on-site. It’s believed that this construction technique for guard rails allows for less wasted space, a high-quality end product, and a more secure fit. These guard rails are commonly used when construction crews want to save time and avoid waiting for guard rails to be shipped to the premises.
Commercially available guard rails are already built when you purchase them and can be made from a wide range of materials, the primary of which include wood and steel. These rails may consist of parts that are made from fencing, mesh, or netting. Just like the other two types of guard rails, commercially available rails come with a mid-rail, top rail, and toe boards.
Temporary guard rails are often stronger than wood and are able to meet OSHA regulations. These railing systems can be placed at the construction site when work begins and removed immediately after the job is finished.
Strength Testing of Job-built Guard Rails
Over the years, tests have been performed on job-built guard rails to make sure that they are able to accommodate the guidelines set by OSHA. As mentioned previously, guard rail systems need to withstand more than 200 pounds of weight when applied at all points along the uppermost edge. The primary strength test for job-built guard rails involves pull-to-failure strength testing, which was developed by the National Institute for Occupational Safety & Health (NIOSH).
The purpose of the pull-to-failure strength test is to assess the highest strength of every guard rail configuration. During this test, a sustained force was applied to the guard rails for a period of two to three seconds. This force was far higher than the 200 pound requirement that OSHA adheres to. With the use of a battery-operated hydraulic pump, two-inch hydraulic cylinder, and cable and pulley system, around 800 pounds of force were generated.
The test results indicate that every guard rail met the 200-pound requirements that OSHA maintains. However, the testing results varied from just over 160 pounds to nearly 600 pounds, which means that the guard rails wouldn’t hold up in every situation. Keep in mind that the ability a structure has to hold up to a shock, impulse, or instant load of 200 pounds isn’t the same as its ability to hold up against a continuous and dynamic load, which was present with the pull-to-failure testing.
The wood materials in guard rails began to move in a dynamic manner when a force of more than 200 pounds was applied during testing. In this scenario, shear and bending forces were placed on the fasteners, which is why the pull-to-failure test was also used with nail fasteners.
During testing, a bending moment will take place that either twists the fasteners or pulls them out of the base. In one instance when the guard rail was constructed while the fasteners were in shear conditions, the pull-to-failure strength was 575 pounds. All other instances were measured between 161-319 pounds.
Further testing found that the strength of guard rails wasn’t determined by the wood splitting or not splitting. Using certain fastener patterns can help you get rid of some of the splitting. Make sure that fasteners are evenly distributed throughout the board.
If you’re placing fasteners along the short side of the board, two should give you enough strength. On the wide side, consider using three fasteners that are placed in a triangle pattern. There’s no need to use over four fasteners in a single board. There were times when using five or more fasteners caused the board to crack before a load was administered.
Why Choose QMH?
QMH is a licensed contractor that has the knowledge and experience required to perform and accommodate all warehousing projects. We can help you maintain compliance and will assist you in choosing storage, safety, or security solutions that will enhance your facility.
The guard rail systems we offer at QMH are meant to keep falls from taking place. Falls are almost entirely avoidable if the right guard rails have been installed. A single delivery truck or fork lift collision can put employees in danger and products at risk. Our guard rails and barriers reduce damage and keep downtime at a minimum.
Satisfied customers have told us how much our services have helped them. For instance, Jerome’s Furniture said “It’s a game changer for us. It’s going to make our everyday business a lot more efficient, and it’s going to be a lot smoother.”. Incycle Bicycle stated “QMH really nailed it on all of those core values. I think that you live by them and it’s apparent in the whole process.”.
