What is the primary use of hand tools in home inspection?

The primary use of hand tools in home inspection is for knocking and probing. This is crucial because it helps inspectors assess the condition of structural components, identify potential hidden damage, and check for soundness in various materials. For instance, tapping on wood can reveal soft spots indicative of rot or pest damage, while probing can help determine the integrity of walls, foundations, and other elements.

Other options, while they may involve the use of tools to some extent, do not encompass the primary function of hand tools in the inspection process. Measuring dimensions is essential in some inspections but is typically done using specialized measuring tools rather than hand tools. Cleaning surfaces may be necessary for visibility during an inspection, but it's not a primary purpose of hand tools. Designing layouts is not relevant to the inspection process, as home inspectors do not create layouts but rather evaluate existing conditions. Thus, knocking and probing is the correct answer as it directly relates to the assessment and diagnosis of potential issues within a home.