A working roof can make all the difference to the liveability of a house. Like outdoor pavers, roofing is designed to last a long time. A quality roof can last anywhere from 10 to over 100 years, depending on the material used. From time to time roofs may need to be replaced, for example, where there is excessive exposure to extreme weather or the roof has been subject to brute force.

Roofs and Life Expectancy

Many different materials are used for roofing, from slate, clay and metal to asphalt. Like sandstone pavers for your outdoor spaces, slate on the roof is one of the most attractive and durable materials, and it can last from 30 to 100 years. Asphalt usually lasts from 15 to 20 years; clay, 20 years or more; wood, 10 to 40 years; and metal, from 20 to 40 years or more. Some slate roofs last for over 100 years; Welsh slate for instance has performed well on many Australian roofs since the 1860s. Often the battens and nails fail long before the slate. Welsh slate carries a 100 year guarantee.

Other than external roofing materials, the building design of a roof may also affect its life expectancy. Geography and climate conditions, such as the position of the shingles in relation to the sun, can also impact on how long your roof lasts for. Ventilation of the roof cavity is also important in the longeveity of a roof.

Signs of Damage

These are some of the most common signs of damage from an outdoor inspection. Make sure you have an unobstructed view of your property and take a walk around from all directions. A pair of binoculars may come in handy. You may need to seek professional advice as to whether the damage can be repaired or whether you’ll need a new roof.

  • Missing or cracked slates or shingles. This can be caused by inadequate fastening and worsened by exposure to wind and extreme weather.
  • Poor drainage. Poor drainage, such as clogging gutters and downspouts, can lead to significant indoor damage. While it may be a simple matter of cleaning your roof, sometimes it’s caused by other issues such as damage to the structure of your roof.
  • Other visible signs of damage. Damage flashing, curling, algae growth, missing granules, blistering, buckling, and rotting are all serious signs of damage. If you see these, it’s best to get professional advice about repairs or a new roof.

Indoor inspection:

  • Indoor leakage. Damp walls and roofs indicate that there may be indoor leakage from your roof. Check that it’s not from other causes such as faulty plumbing.
  • Sagging ceilings. Sagging ceilings is one of the clearest signs of faulty roofing that may need replacement.
  • Water damage. Water stains and peeling and chipping paint can be another sign of a faulty roof.
  • Dark spots in the wood. Dark spots in the wood may indicate leakage from the roof. Check whether the dampness is recent or an older problem.
  • Outside lights. If you can see light from the outdoors inside your house, you’ll probably need repairs to your roof and should get your roof thoroughly checked.


It’s a good idea to check your roof several times a year to make sure there are no signs of damage. This is especially true for older houses and allows the homeowner to be alerted to the problem before any damage worsens.

Gutter should be cleaned at least once a year, or more often if you have large deciduous trees surrounding the house. Gutter blockage can cause damage if there is heavy rain. Smaller issues, such as the odd loose tile or minimal leakage, should be repaired quickly.

Only conduct inspections if you’re properly qualified and have the appropriate safety procedures in place. If in doubt, have a professional tiler check your roof on your behalf.