Roof Anchors for Fall Arrest Lifeline Systems

The construction of tall commercial structures is safely accomplished with the help of fall arrest lifeline systems that protect workers in fall hazard areas. Construction companies and owners of buildings are required to provide efficient lifeline systems in strict accordance with existing structural codes on fall arrest. A lifeline system consists of several components with minimum properties specified by the code. However, manufacturers have begun to design even stronger components for fall arrest systems. Fall arrest lifeline systems consist of ropes or lanyards connecting the body to an anchor point, safety belts holding the body conveniently, and anchors usually attached to fixed points. These components work together to absorb energy produced by the impact of fall. They must absorb the mechanical energy produced by the impact of fall, which is determinable by the weight created by gravity. Therefore, all of the components must be sturdily based and wear-resistant. Lifeline system designers put a great importance on the installation of the roof anchors. Since roof anchors receive all the energy being transferred through the lifeline, designers make sure that the anchors are manufactured using high-strength metals and are properly bolted or welded onto the roof surface. Anchors not properly installed can easily collapse under heavy weight. A roof can be installed with a roof anchor or a series of roof anchors depending on its surface area. Commercial buildings with wide roof areas are usually installed with many roof anchors positioned at several points with specific distances. These anchors are connected by a lifeline system that allows a worker to move to far distances on the roof. Nevertheless, for residential roofing with small surface areas, the rope and lanyard can be connected directly to anchor. The base of a roof anchor is a flat plate attached to the corrugated region of the roof either by bolting or by welding. Welding is preferable to bolting because of its neat and secure waterproofing detail. Because of the lifeline connecting two anchors, the energy is absorbed twice as efficiently as a single roof anchor. Installing several roof anchor points is applicable mostly on metal roofing. Other types of roofing require installation of stable metal surface on the points where the anchors are to be welded or bolted. Modern fall arrest systems, however, can already be assembled on concrete or hollow concrete roofing.