Published on: November 30, 2023
The anchor leg of a relay race team is their fastest and final runner, the one expected to make up the distance and overtake the leader or protect the lead across the finish line. The anchor of a bowling team is their best and last bowler, the one expected to toss strikes and give the team the win.
The fall protection anchor on a rooftop bears the full weight of the worker, personal protective equipment (PPE), and the worker’s tools and equipment. Like sports team anchors, the roof anchor is encumbered with high expectations. Although second place in a race wins a silver medal, and second place earns a bowling trophy, a roof anchor can never afford to fail.
There are stringent regulatory standards for anchorages to protect workers. Fortunately, there are different types of compliant and easy-to-use and understand anchorages so that the building owner and facility or safety manager have options to accommodate the type of roof and other factors.
What are the regulatory standards for roof anchors?
The importance of roof anchors is not lost on the Occupational Safety & Health Administration (OSHA). The agency defines an anchorage—1910.140(b)—as “a secure point of attachment for equipment such as lifelines, lanyards, or deceleration devices.”
When used in a rope descent system, as noted in 1910.27(b)(1)(i), each anchorage “must be capable of supporting at least 5,000 lbs. (22.2 kN) in any direction for each employee attached.” According to 29 CFR 1926.502(d)(15), anchors for individuals shall be independent of any anchorages supporting suspended platforms and “be part of a complete personal fall arrest system which maintains a safety factor of at least two.”
The building owner must inform the employer (in writing) that each anchor is identified, tested, and certified to this standard based on an annual inspection by a “qualified” person. Certification of each anchorage must take place at least every 10 years.
Permanent roof anchors – “rest in place.”
Permanent “tieback” anchor posts can be used on flat or sloped roofs and with BUR membrane systems, single-ply membranes, modified bitumen, green roofs, and metal roofs with underlying structures of steel, concrete, or wood. They are a sound choice when workers perform frequent maintenance of HVAC and other systems and equipment on rooftops or are engaged in other dangerous tasks, for example:
- Operating on self-powered or roof-powered platforms and stages.
- Using window washing Davit systems or building and facade maintenance systems.
- Working with a rope descent appliance.
- Traversing near where leading-edge hazards exist.
- Handling temporary rigging equipment.
New construction is the ideal time to install any of three types of permanent anchorage systems:
Bolt-Around – uses connector rods and a backer plate to bolt around steel, concrete, or wood structures.
Embedded – casts directly onto new concrete roof slabs (with a minimum grade of 3000 psi and 7-in. thickness.
Welded – welds directly into new structural steel.
For existing buildings, there are also three types of retrofit options:
Bolt-On – clamps directly onto existing structural steel.
Chemical Adhesive – fastens onto concrete roof slabs (with a minimum grade of 3000 psi and 8-in. thickness).
Welded – welds directly into existing structural steel.
A post height of 20-in. standard is recommended with insulated HSS cavities to help ensure the durability of the system and the mounting structure by countering thermal bridging and condensation. A hot-dipped galvanized steel exterior provides corrosion resistance.
Mobile roof anchors – “in the right place at the right time.”
Mobile (or portable) roof anchors feature an anchor post linked to rubber-coated base weights with more than 100 suction cups to provide friction against the roof membrane and reduce movement during a fall arrest event. This also spreads the load to protect the worker and the rooftop. Designed for flat and low-slope roofs, they offer several advantages:
- Does not penetrate the roof.
- Easy to assemble and install—can be planned for new construction or be the solution for existing buildings.
- Can be placed when and where needed—and moved if necessary.
- Can be modified to accommodate a horizontal lifeline system.
- Can be modified to accommodate an “over-the-edge” system for window washing and other cleaning or repairs.
Which solution is best for you?
If you are a building owner or facility/safety manager responsible for rooftop fall protection systems that need anchorages, contact Flexible Lifeline Systems. We can discuss your needs and concerns about regulatory compliance, visit your site to conduct a safety audit and map out a plan of action. Our services can include as little or as much as you need, from design, engineering, and fabrication to installation, training, and other support.