March 18, 2020
Skylights allow sunlight to enter buildings, making them more energy efficient than if they only had vertical windows. It also provides workers with more natural light, which can improve health and morale. Skylights are highly popular features in modern buildings, with the American Architectural Manufacturers Association (AAMA) reporting sales of about 275,000 commercial skylights each year in the United States.
However, skylights also present an occupational hazard for workers who have regular access to flat or low-sloped roofs, which include personnel in fields such as electrical, HVAC, plumbing, roofing and telecommunications. Falling is a leading cause of occupational deaths in the U.S., accounting for nearly 40 percent of construction worker deaths in 2017. Many of these deaths were caused by workers falling through skylights. The AAMA estimates that over 120,000 roofers alone are at risk of falling through a skylight while working. As a result, the U.S. Occupational Safety and Health Administration (OSHA) has safety standards on skylights that Vtech meets or exceeds.
The OSHA Act updated many of OSHA’s safety criteria in 2017, which are described in the Code of Federal Regulations (CFR), Chapter 29. This legislation made several significant changes to the requirements for protecting workers from falls through skylight openings. In particular, the new rules omit some of the previous language on this issue without replacing it. As a result, building owners and contractors have greater flexibility on compliance, but they also have greater uncertainty over how they should demonstrate that compliance.
The OSHA Act of 2017 removed paragraph 29 CFR 1910.23 (a)(4), which specifically addressed skylights screens. This paragraph required skylight screens to support at least 200 pounds without breaking or deflecting sufficiently to break the glass under the screen. This paragraph also specified that the openings in the grillwork couldn’t be longer than four inches, nor could the openings be more than four inches wide.
The removal of this paragraph was largely in response to the AAMA Skylight and Sloped Glazing Council’s (SSGC’s) criticisms about it. For example, it stated that a 200-pound load wasn’t sufficient by itself because a relatively weak screen can pass this test if the load is carefully applied. The AAMS stated this test should involve dropping the weight to generate the force of a falling worker more accurately. It also questioned the need for the screen to protect the skylight, when its purpose should be to protect a falling worker. Furthermore, a skylight is often stronger than its screen, although the previous language didn’t clearly state that the skylight should actually cover the opening in the roof.
While the current OSHA regulations have removed the problematic language, the lack of any replacement language leaves the safety requirements for skylights open to considerable interpretation. The AAMA SSGC has been working with other individuals and organizations to develop ASTM E06.51.25, which is intended to address these shortcomings. This standard is currently in draft form, although it’s expected to pass in the near future with few changes. However, it isn’t possible for a skylight to be OSHA-compliant at this time due to the lack of clear requirements.
Vtech has conducted its own tests to address the AAMA’s concerns over the current language in 29 CFR 1910.23. For example, we placed a 200 lb. bag of lead shot with a diameter of one foot in the middle of a skylight for one minute, and the glass held. We then lifted this bag to a height of five feet and dropped it 13 inches from the edge of the glass, and it bounced off the skylight without breaking it.
The current draft of ASTM E06.51.25 requires a drop of 300 lbs. from a height of three feet less the skylight’s curb height. This test must be performed at three locations, including the center, corner and edge of the glass. The weight bounced off the glass for this test, although the glass did crack. Nevertheless, the weight failed to penetrate the skylight.
We then performed an extreme test that far exceeds the previous ones. We carefully placed a 600 lb. weight on the glass, which didn’t crack. The next test was to drop that weight from a height of three feet, which broke the glass. However, the laminate still supported the weight.
These tests show that the safety of those on the roof is our top priority here at Vtech. Our skylights are designed to add an extra layer of safety to one of the most dangerous parts of your building. Although the top of your roof may never be absolutely safe, our skylights will help make it as safe as possible. Contact us today to learn more!