Many home inspectors create potential problems for themselves because the client does not understand what the inspection will cover. For this reason, InterNACHI® encourages inspectors to always have the client sign the InterNACHI® Agreement (between inspector and client) that specifies what the inspector is going to do.
Radon gas kills. So, if the inspection is in a high radon area, or if the inspector discovers a radon mitigation system during the inspection and the client doesn't want to order radon testing, the inspector might consider having the client sign a separate waiver of radon testing.
Note: InterNACHI® markets members who offer radon testing using various covert websites. If you are a member who offers radon testing or other ancillary inspections, add those services to your profile at https://www.nachi.org/ancillary-services.htm