Repair or Replace in Perth
How Perth's Housing Stock Decides the Answer
The repair-or-replace answer in Perth is written largely by the era of the property. The city's dominant re-roofing market — the 1960s and 1970s concrete-tile estates at Letham, Tulloch, Muirton, and Craigie — is now comprehensively into the replacement window. These roofs are 50–60 years old, their fixings corroded, and once nail sickness is widespread across a slope, repairing tile-by-tile is money wasted because the untouched tiles are next to go.
The Cost-Per-Remaining-Year Test
The honest way to compare is cost-per-remaining-year. A £6,000 concrete-tile re-roof on a Letham semi that then lasts 45 years costs about £135 a year. Against that, repeated £350–£450 repairs every year or two, plus the internal water damage between failures, quickly exceed replacement while leaving you with a roof still at end of life. On these estates, once the fixings have gone, replacement is both cheaper and less stressful over any sensible horizon.
When Repair Is the Right Call in Perth
Equally, we turn down re-roofing work when it would be oversell. A slipped tile or a single failed lead flashing on a sound twenty-year-old roof in Scone or Bridge of Earn is a repair, full stop. A Victorian slate roof in Kinnoull with sound slate on failing nails may need only selective re-nailing, not a full strip — saving thousands. Slate lasts 80–150 years, so a Perth slate roof is rarely a replacement candidate on age alone; it is the fixings and flashings that usually need attention, not the slate itself.
The 30% Rule and Perth Roofs
The rule of thumb we apply: once roughly a third of the covering on a slope has failed, slipped, or delaminated, replacement beats repair. Below that, targeted repair is usually right. On Perth's concrete-tile estates the 30% threshold is often crossed silently — a roof looks mostly intact from the ground while a third of its fixings have quietly failed, which is why a proper survey, not a pavement glance, is what should decide it.
