life expectancy used in 4-point inspection

Why in a 4-point inspection is 15 years used for the life expectancy of a a shingle roof, when I have 25 year shingles. Please call me 941-924-7036

Shingles are like tires. They never get their expected life, especially down here in Florida due to the intense heat. Other factors also play into when a roof will need to be replaced, not just the life expectancy of the shingles.

Because the normal life for a 3 tab shingle is 12-15 years. Shingles never last as long as the manufacturer states in Florida.

The following factors affect the lifespan of roof-covering materials

  • Roofing material quality: Better quality materials generally last longer.
  • Installation method: Improper installation may reduce lifespan.
  • Number of layers: Roofs installed over existing roofs will have reduced lifespan.
  • Structure orientation: South-facing roofs will have shorter lifespans.
  • Degree of roof slope: Flatter roofs will have shorter lifespans.
  • Climate zone (snow & rain): Harsh climates shorten roof lifespans.
  • Temperature swings: climates with large daily temperature differentials (within 24-hour cycles) will shorten roof lifespans.
  • Homesite conditions (overhanging tree branches, wind, etc.)
  • Roof color: Darker roofs absorb more heat which shortens roof lifespan.
  • Elevation: Homes at higher elevations are exposed to more ultra violet (UV) light, which shortens roof lifespan.
  • Home orientation: Roofs which receive more sun deteriorate more quickly than roofs which receive less sun.
  • Roof structure ventilation: Poor ventilation shortens roof lifespans.
  • Quality of maintenance: Poor maintenance will reduce lifespan.