Designing and installing a roof anchor system is more than just choosing anchor points. It is a comprehensive process that begins with understanding the intent behind the design and ends with a fully certified, code-compliant fall protection system. This blog will walk you through every stage, from key considerations and engineering to safe installation and final inspection.
Key Considerations for Designing & Manufacturing Roof Anchor
Design Intent
First, we must know the intent of the design—whether it's to protect facade maintenance workers suspended off the lines or act as a tie-back anchor for rooftop workers. The design principles provide a detailed look into the principles that underpin the design and installation.
Load Capacity
A typical Pro-Bel anchor is designed to meet a 1,000 lb static load and an ultimate load of 5,000 lb.
- Static Load: The constant fixed load that the anchor can support.
- Ultimate Load: The maximum load the anchor can withstand without fracturing.
Size of the roof anchor
Next, you need to determine the desired size of the anchor. Standard Pro-Bel sizes include 12″, 15″ and 18”. We can make anchors larger or smaller; however, changes to the standard design may be necessary, such as increasing the outside diameter of the anchor if it needs to be taller.
If you do not know how tall your anchor must be, there is a general rule of thumb: the anchor should typically be 8″ above the finished roofing material to allow for flashing.
Regulatory Compliance
The layout and installation of roof anchors must comply with standards set by safety regulatory bodies, OSHA, and ANSI, which dictate specific requirements, such as the offset angle for suspension (typically 25 to 30 degrees).
Material Selection
Roof anchors are usually made of steel or aluminum. The choice of material depends on the specific application and environmental conditions.
Installing a roof anchor system
For roof anchor installation, you must first know how the anchor will be attached to the structure. The base is customized to match the structure, whether it is wood, cement, steel, or prescient, etc. The base can be welded into the I-beams, cast in place, bolted through, adhered with adhesive, or wrapped around.
Read our step-by-step guide for roof anchor installation
Roof anchor bases
All roof anchors' bases are customized to match the building's structure. Pro-Bel has a base for each roof anchor to match whether the rooftop structure is wood, steel, concrete, or prescient. Other factors, such as the structure's width, will also be taken into account when customizing the roof anchor accordingly.
Wrap Around: These anchors are applied to retrofits and, as their name suggests, wrap around the existing structure for installation. If necessary, reinforcement is added to the base.
Cast-in-Place: When working with concrete structures, a cast-in-place base is the most cost-effective option. The base plate is fully embedded in concrete during installation, resulting in less material being used for manufacturing. Additionally, these anchors can typically be installed by the roofer, eliminating the need for professional installation costs.
Bolt-through: Customizable bolt-through anchors are a breeze to install. They're used on curved steel or existing concrete and steel structures, providing an alternative to welding. With bolt-through roof anchors, the accessibility to the underside of the slab must be considered. This anchor needs to avoid piercing through drywall and plaster ceilings, but with proper precautions, installation is straightforward.
Welded: Weldment anchors are used on steel structures primarily in new constructions; however, they can be used for retrofits with extreme caution and a fire watch in place. These anchors are welded directly into the structural steel beams. Therefore, the anchorage layout design must accommodate the structure by only placing them on the I-beams.
Weld to embedded plate: This anchor is typically used in hollow slabs in new construction. The cast-in-embed structure is cast into adjacent “cores,” and a weldment anchor (without a base plate) is later welded to the top of the embed plate. These anchors facilitate easy and cost-effective on-site installation.
Contact our roof anchor experts, who will help you design and install the perfect roof anchor for your building's specifications!
Permanent roof anchors are the most commonly installed in the fall protection and window washing equipment industry. They serve as secure attachment points for various safety systems, ensuring the safety of workers at height.
What is a Permanent Roof Anchor?
A permanent roof anchor is a basic post with a U-bar attached to the top. Looks can be deceiving, and when it comes to roof anchors, there is much more than meets the eye because, as explained in our guide to roof anchors, they can be referred to by several different names.
What does a permanent roof anchor look like?
How does a roof anchor system work?
In window cleaning, a minimum of two anchors will be used for each worker. One anchor will support the worker, who is directly tied back to their harness. More anchors will be used to support their suspended equipment, whether it be a Bosan’s chair, powered platform, or other suspended equipment.
An anchor may also be part of a horizontal lifeline system in which cable is passed through anchors and connected at the end anchor points. In this scenario, the worker is attached to the cable instead of the anchor.
Window Washing Anchors vs. Window Washing Davits: Which Is Right for Your Building?
Choosing the right rooftop anchor system is crucial; two common options are permanent roof anchors paired with Bosun’s chairs and davits paired with a platform.
Roof anchors can withstand a static load of up to 1,000 pounds and an ultimate load of 5,000 pounds. They are the preferred method for low and mid-rise buildings, given that window washers only need to suspend themselves on a Bosun’s chair at lower heights.
Window washing davits can have mobile or fixed arms and can be attached to a permanent base that is secured to the structure. They are required on buildings with a drop of over 150 meters (approximately 492.13 feet), but in some instances, davits may also be installed on smaller buildings.
Check out our guide to learn when roof anchors and davits are required for window washing.
How is a window washing/fall protection anchor system designed?
Pro-Bel offers free design services for eligible projects. We will typically review your building, including the roof plan, elevations, all sections, and floor plans. The goal is to determine the most effective method of cleaning the building using permanent roof anchors.
Once we have determined the correct method, we will begin to lay out the system to meet national and local codes and standards. The goal is to provide a system that is code compliant, efficient to use, and cost-effective.
As always, it is recommended that you consult a reputable manufacturer such as Pro-Bel whenever designing window washing equipment or fall protection systems. These systems protect workers from potentially catastrophic accidents, and the design of these systems is a highly specialized field.
Safety is the top priority, and proper installation, along with regular inspections, is essential for ensuring the security of these fall protection systems.
Read our in-depth guide for the top 6 considerations for designing a fall protection system
Ultimately, a designer with years of experience determining the optimal layout can make the best call.
Need Help With Code-Compliant Roof Anchor Design?
Work with Pro-Bel’s engineers to develop a fully compliant, cost-effective fall protection anchor layout tailored to your building’s structure and access needs.
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