Decking
The surface boards or panels that form the walkable platform of a deck or the structural sheathing on a roof.
In outdoor deck construction, "decking" refers to the horizontal boards that form the walking surface. Common materials include pressure-treated pine (most affordable), composite lumber (low maintenance, mid-to-high cost), hardwoods like ipe or tigerwood, and PVC decking (fully synthetic). Each material has different price points, longevity, and maintenance requirements.
In roofing, "roof decking" or "roof sheathing" refers to the structural panel layer—usually 1/2-inch or 5/8-inch OSB or plywood—that is fastened to the roof rafters or trusses and serves as the nail base for roofing materials. Damaged or soft decking is commonly discovered during a re-roofing job and must be replaced before new shingles can be installed.
Decking costs for an outdoor deck run $2–$10 per square foot for materials alone, with composite and hardwoods at the high end. Roof decking replacement costs $70–$100 per sheet of plywood (4×8) including labor, and most roofers include a per-sheet allowance in their bid for damaged panels.
Real-World Example
The roofing contractor discovered that 12 sheets of roof decking near the chimney had rotted; the replacement added $900 to the re-roofing bill.