Davit Systems

A davit system consists of two primary components, a base and an arm. The base is a permanent fixture of the building structure, and the arm is typically portable, with the ability to be raised, lowered, and removed. In most cases, a davit system will be used to rig a Powered Platform; however, it can also be used with other forms of suspended equipment, such as a single cage or a bosun's chair.

Davit systems can be divided into two distinct categories, each with several subcategories. The first primary category is the ground rigged davit system. This system typically involves a much smaller arm that lifts a powered platform from the ground. The davit arm only requires a small amount of space over the parapet or roof edge.

The second primary category is a roof-rigged davit system. In this scenario, a Permanent Powered Platform is stored on the roof. The davit arms are much taller to allow a greater clearance above the parapet. The platform is rigged at the roof, and a careful series of maneuvers allows it to be moved to the exterior of the building and lowered. This is more common in buildings with unique conditions.

Typically, a davit system will be used in conjunction with Roof Anchors. While the suspended equipment will be rigged to the davit arm, the workers' independent lifeline will be attached to an independent roof anchor. This line and roof anchor will protect the worker in the event of a fall.

A common davit system question is: How many davits will I need? The answer to that question is not very easy. Every building has its own unique conditions and challenges. Important questions you must ask are: What type/size platform will a contractor use? Is a permanently powered platform required? What type of davit arm or base is necessary? Is one set of arms sufficient, or will more be required? Are there local codes or standards that require davits?

Davit Base

The base of a davit system is customized to the specific structure of the building, whether it's concrete or steel; we have a davit base to suit your project’s needs.

For a concrete roof, the davit base can be cast-in-place by the forming contractor and is visually inspected and load-tested by Pro-Bel-certified technicians. A steel roof requires any davit base to be welded to a minimum 10” x 10” surface and typically requires additional reinforcing (i.e., backspan beams) designed by the structural engineer of record.

Wood structures are typically not suited for davit bases due to the high moment induced by the davit arm assembly, which is transferred back to the structure. Although not impossible, it’s recommended to avoid davit bases on wood structures altogether. Thus, a tie-back roof anchor system is the preferred solution. If your building project involves a wood structure, it’s best to contact Pro-Bel early in the design process to coordinate a system that meets your building’s needs.

Here are some of the davit bases Pro-Bel supplies.