Proper Use of a Roofing Anchor Bracket

Bracket Fasteners

• Framing nails are the most common fasteners for roof anchor brackets. Because roof brackets are a temporary feature, vinyl-coated or bright framing nails are usually acceptable for mounting brackets to roof decks. Although size requirements vary according to your bracket manufacturer's specifications, most brackets require at least 20-penny or "20d" framing nails. Aside from lag-type screws, wood and metal screws rarely meet the standards for securely anchoring brackets to roofs. Consult your bracket manufacturer's guidelines to determine whether nails or screws are acceptable for your particular model.

Installation Location

• Regardless of bracket make and model, bracket fasteners must penetrate through the roof's decking and into underlying roof framing materials, such as solid lumber rafters or joists. Only nails driven into rafters or joists provide enough gripping strength to safely hold the brackets in position. Additionally, bracket spacing affects the safety of a bracket installation. Manufacturers typically recommend spacing brackets no more than 8 feet apart. However, spacing requirements might vary according to bracket make and model.

Support Plank Installation

• To increase the strength of the support plank, bracket manufacturers advise builders to install planks that extend slightly beyond the ends of the outermost brackets. Therefore, you should cut support planks longer than the span between the outermost brackets of the installation. Although exact requirements vary according to product type, many manufacturers advise builders to install planks that extend at least 6 inches beyond the brackets' ends, yet no more than 12 inches. Only solid lumber at least 1 1/2 inches thick, called "2-by," is suitable for support material. Additionally, the quality of the lumber affects the plank's performance; avoid knotty or damaged wood.

Additional Safety Equipment

• Roofers use several types of safety equipment in addition to roofing anchor brackets. Common roofing safety equipment includes safety harness assemblies and temporary guard rails. Safety harness assemblies typically consist of loop-like anchors mounted to a roof's ridge line. A rope or lanyard attaches to the anchor at one end and to a roofer's safety vest or belt at the other. Guard rails are essentially temporary, roof-mounted fences. Guard rail systems might consist of modular metal tubing mounted to base plates, or simply brackets that allow roofers to build custom wooden rails.