Not long ago, NFT published an extensive study on consumer complaints related to the floor covering industry. For retailers and installers, the bottom line was the emphasis on responding promptly and scheduling the recommended repairs.
Telling the customer point-blank that the situation is it not your problem is likely to only escalate the problem. Choose your words wisely. After agreeing on the conclusion of the inspection, work with the customer to formulate a time table for repairs.
The first step, of course, is to eliminate the source of the moisture. Second, allow ample time for the hardwood and subfloor to dry. Then proceed with repairs only after the flooring has reverted back to an acceptable moisture level. In some cases, the problem will correct itself. Avoid rushing the repairs. (Remember, the cupping process occurred gradually.) If there is large-scale cupping, remove boards along the wall line. Ventilate and dehumidify the area. Stay in touch with the customer on a periodic basis to gauge the progress of drying.
After a sufficient time has elapsed, and the flooring is considered dry, proceed with any repairs that may be required. If you are working with prefinished hardwood, remove the hardwood units that are unacceptable and replace with the same hardwood flooring as originally installed. If the original installation was job site finished, sand the cupped areas and blend with the existing wood using stain and finish. But remember: Prematurely sanding a cupped hardwood that is not at an acceptable moisture level will only create additional damage to the hardwood flooring. The flooring that was cupped will not be convexed in appearance after the hardwood is finally dry and well after the sanding has been completed.
Put it this way: Hardwood floors that have been damaged by water normally require a mere "lifeboat" repair and not the utilization of the entire "Naval Fleet" normally associated with other floor covering materials. While it is important to let the customer know you are eager to resolve the situation, when it comes to the repair job, remember the phrase you have heard since preschool: "haste makes waste."
Rushing the repair job is like applying a Band-Aid to a severe cut. It may only stop the bleeding for a short period of time but you may still need major surgery in the not too distant future.