When it comes to roof coverings, the old adage applies: You get what you pay for. This is particularly true when considering their lifespans, ranging from inexpensive roll roofing with a projected lifespan of fewer than 10 years to pricier slate roofs, which, if impeccably maintained, could outlive several owners at up to 150 years.
But there are serious caveats when attempting to pin lifespan projections on any roof covering. In a perfect world, all roof coverings would live out their full functional lives, but as any homeowner and home inspector know, roofs do not exist in a vacuum. There are a number of natural and man-made factors that can have a profound effect on whether a roof covering will serve reliably for years or meet an untimely demise. These include the weather; shoddy workmanship; objects striking the roof; manufacturer defects; roof position relative to the sun; region-specific pollutants; harmful roof vegetation; and lack of insulation and poor ventilation, both of which promote moisture and can expedite degradation.
If you’re in the market for a new home, you’ll want to make sure to hire a certified home inspector with experience in identifying types of roof coverings, assessing visual deficiencies, making recommendations on needed repairs or replacements, and offering advice on maintenance.
For more than 26 years, the certified inspectors at A-Pro Home Inspection have reported on their fair share of roof covering problems. Here are a few to consider:
Asphalt Shingles: Asphalt shingles are prone to damage from precipitation and sunlight that can deteriorate their protective granule covering, leaving them vulnerable to decay, shrinkage, fractures, curling (turned up edges), and cupping (center depressions). The inspector will note obvious impact damage from hail and missing shingles victimized by strong winds. Topping the list of installation errors are nails that have been overdriven or incorrectly located on the shingle. This can lead to the shingles sliding and being ripped out of their nail holes.
Roll Roofing: Use of ninety-pound roll roofing, sometimes installed on a small section of a roof, will often be cited by the home inspector as an amateurish repair. Other common issues include bubbling; end-of-life indicators, such as fractures or loss of granule covering; and placement over a non-flat surface, which can make roll roofing’s already short lifespan even shorter.
Single-Ply Membrane Roofing: While having a longer projected lifespan than roll roofing (15 to 25 years), single-ply membrane roofing has a number of concerns that will draw the home inspector’s attention, including punctures, non-waterproofed roof penetrations, and leaks at the seams, frequently caused by UV-related degradation of adhesives.
Slate Roofing: The inspector will report on tiles that are missing or broken. Evidence of a large amount of dislodged tiles could be the result of fasteners that are degrading long before the slate is ready to call it quits. Other common problems include inadequate repairs, failed metal flashing, and undetected imperfections in the original stone, which may cause breakage later on. It is not uncommon for damage to result from people walking on the roof.
Clay and Concrete Tiles: Like slate roofs, foot traffic can cause damage to clay and concrete tiles. Their brittleness makes them susceptible to impact damage from falling branches and other projectiles. The inspector will note broken, missing, and out-of-position tiles; obvious DIY jobs (a major mistake considering the precision required for proper installation); or evidence of water exiting the roof from underneath the covering.
Wood Shingles and Shakes: Usually made from cedar, wood shingles and their rougher-looking cousin, wood shakes, suffer as a result of weathering from sun and precipitation. This may appear in the form of discoloring, cupping, curling, and wear. Other issues include a range of installation errors, from missing underlayment to buckling caused by lack of spacing between nailed shingles; termites and other wood-boring insects; wood rot due to improper ventilation; flashing problems; and neglect, especially in the case of owners who don’t pay close attention to moisture concerns.