The answer to 'what is roof decking' is the structural base layer of a roof that supports the roofing materials. Roof decking is typically made of plywood, oriented strand board (OSB), or dimensional lumber and is installed directly over the roof framing members like trusses or rafters. It provides a stable, solid surface for the roofing materials to be installed on top of.
Roof decking is an essential component of a roof system, as it transfers the weight of the roofing materials, snow, wind, and other loads down to the roof framing. It also helps to stiffen and stabilize the roof structure, preventing sagging or movement. Proper installation of the roof decking is critical to ensure the long-term performance and integrity of the roof.