Roofs and Roofing Systems

One of the most frequent questions I hear as a home inspector is; “Are there any problems with the roof?” When we identify with a problematic home, we envision buckets collecting water from a leaky roof. Although there may be many other issues in a home, a leaky roof, complete with stains and even mold, is very visible, and therefore, very important to home buyers.

Roof inspections start with an overview, looking for anything out of the ordinary. Obvious damage, wind peeling back shingles, missing or broken roofing tiles, branches from trees scraping rake-edge tiles or shingles loose, or deteriorated roof-covering materials, these are all obvious signs of roof distress.

The type of roof covering determines the items inspected during the roof inspection and survey. For example: if you have a concrete tile roof, which is by far the most common type in Las Vegas (approx. 90%), you have concerns about the placement and condition of the roof tiles. The concrete tiles in themselves do not waterproof the roof, they protect the roofing paper under them, which actually waterproofs the roof. Concrete tile roofs are considered a 50 year roof in most cases, however, regular maintenance is still necessary to assure the longest roof life.

If a tile or tiles are broken or missing or slipped from position, they can allow the weather, and more damaging…the UV from the strong desert sun, to deteriorate the underlying roofing paper, contributing to roof leaks. By comparison, asphalt composition shingles, nationally considered to be a 25 to 30 year roof material, may last only 15 to 20 years here in the desert. The south slope of an asphalt shingle roof takes the brunt of the sun’s damage, and areas of roof deck penetration, such as roof vents, plumbing or heating vents, ductwork, etc…and their flashings, deteriorate over the course of only a few years, requiring general maintenance to touch up and re-coat the Mastic tar flashing materials.

Asphalt Composition Shingles can start to degranulate and decompose after only 10 to 12 years, depending on their installation and slope. And since we spoke of slope, the slope, or “angle” that the roof slopes, can create an entirely different problem. Concrete tile roofs have slope limitations to prevent the weather from entering under the tiles and damaging the roof paper. Asphalt Composition Shingles also have problems if laid on slopes that are too shallow, allowing the wind and weather to peel them back and moisture to enter the underlaiment.

Hot roofs, Gravel roofs are typically used on commercial buildings, but may also be found on residential structures. Clay roofing tiles are very rare, basically because they are very expensive, as are metal and copper roofs, and are typically found on high-end homes.

Other types of roofs and materials include flat or low sloped roofs, Shed roofs, Gable, Mansard, and roof coverings such as rock and gravel, hot roofing, wood shakes or shingles (popular during the 70’s and early 80’s), modified Bitumen roofing, rolled paper, and any number of metal roof materials. I have actually seen a roof covered in metal license plates!

Foam roofing materials, seen usually on Manufactured Homes, is a Polyurethane-based roofing material, and is considered to be a five year roof. This type of roof is also considered a “temporary repair” to old or deteriorated roofs. Foam roofing needs annual maintenance, including a protective coating, which needs to be re-applied as it wears from the sun and elements. When a foam roof is replaced, it generally needs to be removed all the way down to the roof decking, removing all traces of the foam roof and anything it has attached itself to. It can be a costly repair and replacement.

Whatever the roof design, slope, or type of roof covering, they all require a thorough visual inspection. The State of Nevada, Real Estate Division, regulates how licensed home inspectors inspect roofs. We are not permitted to walk on concrete or clay tiles, unless we are licensed to certify roofs. In addition, we cannot enter a roof unless the access edge is 12′ or less. On a hot sunny day, stepping onto an asphalt roof could damage the materials, so care must be taken by the inspector.

Roofs are examined from the exterior…and interior (attic) to identify problems and leaks. The roof structure is also inspected for damage, improper repairs, sagging, missing or broken trusses, and moisture stains from water intrusion. All flashings from roof penetrations are visually inspected top and bottom to assure their functionality.