Weighted Anchor Systems

OSHA requires an anchorage used for personal fall arrest to support at least 5,000 pounds for each employee attached, or to be designed, installed, and used under the supervision of a qualified person as part of a complete personal fall arrest system that maintains a safety factor of at least two (29 CFR 1910.140(c)(13) general industry; 29 CFR 1926.502(d)(15) construction). A weighted anchor system complies through the engineered path: dead weight arranged in an engineered geometry resists the forces of an arrested fall with no connection into the roof structure. That only works when a qualified person has run the design for the specific roof and surface, so the calculations belong with the system as its compliance record.

Fall protection generally sorts into four approaches: elimination or prevention (removing the hazard or guarding it with passive systems like guardrails), fall restraint (keeping a worker back from the edge so a fall cannot start), fall arrest (stopping a fall in progress with a harness, connector, and anchor), and administrative controls (warning lines, training, and procedures). A weighted anchor system serves the restraint and arrest tiers on roofs where nothing can penetrate the membrane and no structure exists to fasten to. Used in restraint mode, it keeps the worker from reaching the edge at all, which is the stronger position.

OSHA’s general industry standard sets the trigger at 4 feet above a lower level (29 CFR 1910.28(b)(1)); construction work triggers at 6 feet (29 CFR 1926.501(b)(1)). Roof maintenance on an existing building is general industry work, so the 4-foot duty applies to the crews a weighted anchor system protects. Tritech designs and installs weighted systems where the roof warranty or the deck rules out penetrations.