You need a home inspector. When you hire an inspector, you are hiring an experienced professional who has training and experience in the building industry. It is the job of home inspectors to not only evaluate the condition of the house's major systems and structural integrity, but also to evaluate how these systems are working together and identify areas that need to be watched, repaired or replaced.
Inspectors give you the Big Picture analysis of the home you are purchasing. If an inspector identifies the need for a costly, detailed analysis of any of the houses' systems or structure, they will recommend the appropriate professional, which may be an experienced engineer with expertise analyzing that particular system or structure. The need for this kind of expensive, detailed analysis is rare.
Hiring a Professional Engineer on your own can be a disappointing experience. The term Professional Engineer does not mean that the individual has training or experience conducting home inspections. Additionally, a home inspection does not involve engineering analysis. Therefore, hiring a Professional Engineer to complete an inspection undoubtedly costs more and may not give you the results you desire and deserve.