To help reduce liability and increase clarity, home inspectors should report upon the “roof-covering” or the “roof-covering materials” that were observed during the home inspection. They should NOT report upon the “roof system,” “roofing,” or “roof assembly,” the components of which are not readily observable.
According to the InterNACHI® Home Inspection Standards of Practice (www.nachi.org/sop), the inspector shall inspect the roof-covering materials from the ground level or eaves.
Components of a roof system or roof assembly are not readily visible during a visual-only inspection. The components of a roof system or assembly may include the roof deck, load-bearing components, trusses, underlayment, substrate, fasteners, thermal barrier, vapor retarder, insulation, ventilation, and the roof covering. Can home inspectors see underlayment? No. Fasteners? No. Decking? No.
“Roof covering” is a term specifically used and defined in the International Residential Code and building standards. Roof covering is the covering applied to the roof deck for weather resistance, fire classification or appearance. And since the covering is layered, not all of the covering material is visible during a home inspection. The other terms reference a combination of components used together to form a complete assembly. Roof covering and roof-covering materials are typically visible during a visual-only home inspection. A system is made of its parts. An assembly is made of smaller components. And most of the smaller parts and components are not readily visible. They are beyond the scope of a home inspection.
The focus for the home inspector should be on roof coverings. A variety of roof-covering materials may be installed on a house or building to be inspected, such as asphalt shingles, clay and concrete tile, metal roof shingles, wood shingles and shakes, and metal roof panels. For example, built-up roof covering is defined in the International Residential Code as a common roof covering for houses and buildings with relatively flat roofs, and made up of two or more layers of felt cemented together and surfaced with a cap sheet, mineral aggregate, smooth coating or similar surfacing material.
Remember, just about everything (every component and system) is limited and restricted in some way for the inspector during the visual-only home inspection.
You’ll find this training and more in InterNACHI’s free, online “How to Perform Roof Inspections Course” provided by InterNACHI® School, the only nationally accredited home inspector college, at internachi.edu.
Become an InterNACHI® Certified Roof Inspector by visiting Become a Certified Roof Inspector - InterNACHI®.