This is the question most homeowners are really asking when they call a roofer. The honest answer depends less on the age of the roof than on what is happening underneath it.
Signals that point to repair
- One identifiable defect in one place
- Surrounding covering in good condition
- Fixings sound — nothing else moving
- Underlay intact when viewed from the loft
- No history of repeat problems
Signals that point to replacement
- Repairs needed several times a year, in different places
- Slates slipping with no storm to blame — usually corroded nails
- Underlay torn, sagging or crumbling to the touch
- Widespread delamination or spalling across the covering
- The roof is at or beyond the service life of its material
The five-year test
Add up what repairs are likely to cost over the next five years and compare that with the cost of re-covering once. If the two numbers are close, re-covering usually wins because it also resets the underlay, battens, flashings and ventilation.
Be wary of anyone who recommends a full replacement without going into the loft or showing you photographs of the defects.