Decking is the plywood or OSB layer under your shingles, and replacing it is **the most common surprise cost on a roof replacement** — because nobody can see it until the old roof comes off.
What drives the number:
– **It’s priced per sheet,** in standard 4 ft by 8 ft panels.
– **Most Houston roofs need somewhere between zero and six sheets.** A roof with no leak history often needs none.
– **More than eight sheets usually means a long-running leak** that went unaddressed, or inadequate attic ventilation cooking the deck from below.
– **Older homes may have plank decking** rather than sheets, which changes the repair approach.
The important thing isn’t the price, it’s **getting it in writing before work starts**. A bid that doesn’t state a per-sheet rate leaves the number open on a day when your roof is already torn off and you have no leverage.
Ask every contractor for their per-sheet decking price up front. We put it in the contract, we photograph every sheet we replace, and you only pay for what came out.