This has always been a tough issue. When a project fails to pass the final sampling, it is primarily the result of either inadequate remediation and cleaning, or there exists a reservoir of mold that is hidden. If the contractor did an inadequate job of remediation and cleaning, then he/she should not only complete the project at his/her cost, but the contractor should also cover the cost of additional testing until clearance is attained. The most important thing for the homeowner to remember is that the consultant (Pacific IAQ) has a contract with the homeowner, not the contractor. All additional sampling costs are invoiced to the homeowner or client, and its up to the client to negotiate the additional costs with the contractor. In the event of one or more failures, Pacific IAQ recommends that the homeowner withhold the contractors final payment until the cost of additional testing has been negotiated.
If the failure is the result of a hidden reservoir of mold, then additional investigation and remediation is necessary. Pacific IAQ always recommends that drywall removal extend at least two feet beyond the last visible water staining or mold growth so that we can be assured that there are no additional mold reservoirs. Occasionally, additional areas are discovered that may or may not be related to the specific problem you are remediating. In these circumstances, the additional work and testing are considered part of the project and are generally paid for by the homeowner or client.