Decking is the only part of a re-roof that genuinely cannot be priced with certainty in advance, which makes it the part most vulnerable to both honest surprise and dishonest billing. These are the questions that convert it from an open-ended risk into a defined one. Ask them in writing, before you sign anything.
A contractor who has been in your attic and knows your build year should be able to answer with reasoning: continuous panels or spaced boards, probable thickness, likely condition given the age and any staining visible from below. A shrug means the estimate is a number without an assessment behind it.
If you have already looked yourself — and you should — compare their answer to what you saw. Agreement is reassuring. Disagreement is a conversation worth having before work starts.
The most important question on the list, because it is what makes competing bids comparable. Many estimates build in a small allowance. Some include zero. A bid with no allowance looks cheaper and is not.
Get a number. Then, when comparing quotes, mentally normalise them — a bid including six sheets and a bid including none are separated by more than the headline difference suggests.
A stated per-sheet or per-board price, in the contract, before the crew arrives. This single line is the difference between a change you can verify by arithmetic and a charge presented to you at the moment your roof is open and you have no leverage.
Any contractor who declines to commit to a unit rate is asking for unilateral pricing authority. That is worth declining.
The answer you want describes: stop, photograph, count, contact you, obtain approval, then proceed. Written into the contract.
The answer that predicts trouble is any version of we handle it and settle up at the end. Settling up at the end means finding out what you owe after you have lost every opportunity to question it.
Photographs of the damaged areas before replacement, and a count of sheets used. Routine for a contractor operating in good faith, mildly inconvenient for one who is not. That asymmetry is exactly why the question is useful.
Ask for the photographs to be provided with the final invoice, not merely taken.
Replacement material should match existing thickness so the roof plane stays flat — a mismatch telegraphs through the finished shingles as a visible step. Ask about plywood versus OSB and why, and ask whether panel edge clips are included where panel edges fall between rafters.
If skip sheathing is expected, ask for the overlay to be quoted as an explicit line item rather than as a contingency, so it is comparable across bids.
In Seattle this is not a hypothetical. The answer should describe how much roof gets opened at a time, what the dry-in plan is, and what happens if weather turns mid-job. Contractors who work here properly stage tear-off in sections rather than stripping an entire roof and hoping.
A vague answer suggests scheduling habits imported from a drier climate.
Rarely asked and genuinely valuable. On older homes, original sheathing fastening is often sparse or corroded. Re-nailing while the deck is exposed costs very little and materially improves how the roof transfers wind uplift into the structure. Afterwards it is impossible without removing the roof again.
Related, because a great deal of Seattle deck damage comes from condensation rather than leaks. If your deck is being replaced due to moisture from below, replacing the wood without addressing intake, exhaust, and duct terminations installs a new roof over an unchanged cause.
Ask whether baffles are included and whether soffit intake has been verified as functional rather than merely present.
Decay that has reached rafters, rafter tails, or fascia is structural work, generally requires permitting, and is priced separately from sheathing. Establish up front how that is handled and who pulls the permit if it becomes necessary.
None of these questions is adversarial, and a good contractor will answer all ten without friction — several will be pleased to be asked, because it means the eventual conversation about decking will be straightforward rather than fraught.
The information is in the pattern. A contractor who answers all ten specifically and in writing has thought about your roof. One who answers most of them with reassurance rather than detail has thought about closing.
This post is part of our in-depth coverage of roof replacement in Seattle.
We walk the roof, check the attic, and give you a written fixed quote. Serving Seattle and the greater Puget Sound region, open daily 7AM–8PM.
