Common Christchurch roof failures we fix
Christchurch homes take high-amplitude nor'wester wind, heavy seasonal frost, and coastal salt on eastern suburbs. We regularly diagnose and repair these targeted failures:
- Popped nails and tired screw lines: many 2000s long-run roofs need a re-screw with class 4 or class 5 fasteners and correct spacing, not a full re-roof. We inspect first so you are not sold a change-out when fixings are the real problem.
- Rusted fixings and perforated steel: older long-run roofs used lead-head nails or early galvanized screws. Fixings rust out, or thermal movement enlarges holes around the shaft. We replace compromised fasteners with class 4 or class 5 coated screws and oversized EPDM washers to seal each penetration.
- Failed flashing junctions and aprons: flat roof planes rarely leak first. Water enters where surfaces meet. Degraded barge flashings, failed valley linings, and cracked transitions at chimneys or skylights are common entry points. We custom-bend and replace flashings for sharp, reliable water divergence.
- Blocked or inadequate valleys: internal valleys carry huge volume in plains downpours. Leaves, silt, and debris let water back up under the cladding into the ceiling cavity. We clear, realign, or replace rusted valley sections to restore flow.
- Wind lift from nor'westers: high wind exploits loose edge fixings or compromised purlins and lifts whole sheets. We secure lifted iron, reinforce timber where fixings have pulled free, and tie profiles back down to code.
