The morning after rain, Dave looks across the underlayment and sets down the first bundle. A fold catches the light near the eave. Pat has already carried over the tools. "We can be ready," Dave says, "without that being ready." Nobody particularly wants another pause, including the owner watching from the kitchen. Before covering it, establish that the underlayment is dry and acceptably flat, and that the deck underneath is suitable. A schedule does not answer those material questions.
GAF's bulletin on buckled felts specifically advises against installing shingles over wet underlayment and calls for a dry, relatively flat, smooth surface. It explains that trapped moisture and wrinkles can affect the finished shingles. Use that manufacturer guidance for its stated scope, then obtain the requirements for the actual material on your roof.
A Ripple Is a Finding to Explain
A slight surface ripple, a sharp doubled-over fold and a loose sheet moving in wind are different conditions. Record what can be seen safely, then ask the contractor which it is. The response should identify the material, what caused the condition where known, and how it will meet its instructions before covering.
Do not walk onto a partially covered roof to press wrinkles flat. The crew needs to assess the installation with appropriate access and protect the building while doing so.
Some felt distortion can change as the material dries. That does not mean every fold will disappear or every damaged sheet should be retained. Ask what the acceptance check will be after drying, and what condition would require replacement. "It will flatten under the shingles" leaves the important question unanswered.
Different Findings, Different Responses
A dry-looking upper surface does not settle every layer underneath.
Wet underlayment
Establish drying and product condition before covering.
Raised fold
Check whether it relaxes acceptably or requires correction/replacement.
Wet or damaged deck
Assess the wood separately; a new sheet above it is not a repair.
Ready to cover
Record the accepted surface and concealed detail before shingling.
Check Below the Sheet Too
Mike separates the questions on his inspection note: sheet condition, then deck condition. Pat initially points to the sunny surface as evidence that things are improving. It is encouraging, but it cannot establish what happened below an unfinished junction. The sheet can look better while the deck still needs its own assessment.
The contractor should identify where water could have entered, inspect affected areas and decide whether any underlayment needs lifting or replacement to assess the deck. Swollen, deteriorated or otherwise unsuitable decking calls for its own decision, rather than being hidden by a fresh roll.
GAF's Quix instructions separately require a clean, dry deck and installation without wrinkles. Quix is one named synthetic product, not a specification for every felt or membrane. Its requirements illustrate why the layer underneath and the sheet itself need separate checks.
Agree on the Pause, Including Weather Protection
The immediate choice is not simply "cover it" or "leave the house open." Ask how the roof will remain protected while drying or corrective work proceeds. That may affect daily sequencing, the area the crew works on, or temporary protection at unfinished junctions.
Request a short update covering the affected area, proposed action, protection overnight and the next condition check. If drying is weather-dependent, a promise of a fixed number of hours may be less useful than a clear acceptance criterion.
Keep pictures of the initial condition and the surface accepted for shingling. Mark each affected area on a roof sketch, then record the product, observed fold or damage, drying or replacement action, and who accepted the final surface against which instruction. Ask for a close view and a wider location view. Dave wants a record that identifies the repaired patch, not twelve anonymous photographs of grey material. These do not replace an inspection, but they make the explanation reviewable after covering.
Separate a Product Defect From an Installation Problem
If the material is torn, distorted or unsuitable, the contractor and supplier should determine what failed and the appropriate remedy. Do not assume that covering questionable work either automatically cancels every warranty or guarantees a future warranty claim. The cause of any later damage and the actual warranty terms matter.
Before approving extra work, ask which material is being replaced, why, and who bears the cost under the agreement. Keep the practical objective visible: a suitable deck and underlayment ready for the selected shingles.
If the concern is how long a sheet may remain exposed between workdays, our exposure-rating guide tackles a different trap. A UV rating printed on a roll is not a promise that an unfinished roof can protect the house through every storm.