What Are You Really Buying?
Below a professionally installed new roof can be expected to last about 50 years.
Many home owners are delaying re-roofing their homes because modern safety requirements have made scaffolding a typical additional cost to factor in when re-roofing which inflates the cost substantially.
Homes built before 1970 will have roofing systems that are at or near the end of their service life. Your Dunedin building inspector will make a determination upon inspection as to the type, condition and expected service life of the buildings roofing system.
Below an old roof is still in good order and with repainting will serve the building well into the future.
Below corrosion at penetrations and overlaps is common in older iron roofs. This area will leak so needs replaced.
Decramastic (pressed tin) roof below at the end of its service life and needs to be replaced.
As you can see every roof will age differently. A well maintained roof will last longer as will a properly installed roof. Ideally a roof will be in good sound water tight condition, be properly flashed around penetrations, have roofing paper installed, and have sufficient eves creating a good overhang for the cladding system to reduce the amount of water reaching the cladding system and the soils near the foundations. It’s not just a roof it’s your buildings first line of defense so look after it and keep its gutters clean!
You can see the roof below is reaching the end of its service life. These concrete roofs can be re-coated or resealed to extend their life but consider the economics and look towards replacing with steel/iron.
Below an example of poor design. The chimney directly connects to the roof causing a ponding area. This has caused the framing below to rot.