Roof Decking Calculator
Calculate roof decking costs by material and replacement area. Compare OSB and plywood with installation labor.
How It Works
Enter roof area
Input total roof area in square feet or use the roof area calculator first.
Choose material
Select OSB (oriented strand board) or plywood — OSB is cheaper, plywood is stronger.
Set replacement percentage
Partial replacement (damaged sections only) is common — set your estimated coverage.
Frequently Asked Questions
How much does roof decking replacement cost?
Roof decking replacement costs $70–$100 per 4×8 sheet of OSB installed, or $90–$130 per sheet of plywood installed. Full roof decking replacement on a 2,000 sq ft home costs $2,500–$5,500 depending on material and labor rates. Partial replacement of damaged sections runs $200–$1,000 per area.
OSB vs plywood roof decking: which is better?
OSB (oriented strand board) is less expensive ($30–$45 per sheet) and is the standard for new construction. Plywood ($45–$70 per sheet) is stronger, holds fasteners better, and handles moisture more forgivingly. For re-roofing over existing decking, matching the original material is usually fine. For areas with high humidity or potential moisture exposure, plywood is the better choice.
When does roof decking need to be replaced?
Replace roof decking when you find soft spots or sagging when walking on the roof, visible rot or mold, water damage with staining or swelling, delamination (layers separating), or when the wood crumbles rather than holding nails. During a re-roof, contractors inspect all decking and replace damaged sections. Expect 5–15% decking replacement on older roofs.
Is roof decking included in a roof replacement quote?
Most roof replacement quotes include a small allowance for decking replacement (typically 2–5%). Additional damaged decking discovered during the job is usually billed separately at $3–$5 per sq ft. Always clarify with your contractor what is included and the per-sheet rate for additional decking before signing the contract.