Start inside during or just after rain, mark the highest damp point, then inspect the roof directly above and uphill from it. Check flashing, penetrations, cracked tiles, loose fasteners, and blocked gutters before applying any sealant.
This guide is written for South Africa, Australia, New Zealand. Always check local codes, product specifications, licences, and site conditions.
Step by step
Map the water path
Look for staining, damp insulation, mould, and daylight in the roof space. Water often travels along rafters before it drips.
Inspect uphill
On the roof exterior, begin above the indoor mark and work upward. Pay special attention to valleys, chimneys, vents, skylights, and wall junctions.
Test one zone at a time
With a helper inside, use a gentle hose flow on small roof sections. Wait several minutes between zones so you can isolate the entry point.
Repair the actual detail
Replace broken components and reinstate flashing or fasteners correctly. Sealant is a finishing aid, not a substitute for sound roof detailing.
Expert tips
- Do not walk on a wet, steep, brittle, or unfamiliar roof.
- Photograph the fault before and after repair.
- If water is near wiring or the ceiling is bulging, isolate the area and call a professional.
Common questions
Why does my roof leak only in wind-driven rain?+
Wind can push water uphill or sideways beneath laps and flashing. Inspect exposed edges, side laps, ridge details, and wall junctions.
Can I repair a roof leak from inside?+
An internal patch can reduce damage temporarily, but a durable repair normally needs the exterior entry point corrected.
When should I call a roofer?+
Call a roofer for steep or high roofs, widespread damage, structural sagging, repeated leaks, or any situation you cannot access safely.
Sources & further reading
We link to official building-code, government and public-health material where a technical or safety claim needs authoritative context. Local rules and adopted code editions can change.
- South African GovernmentNational Building Regulations and Building Standards Amendment ActSouth African building-control and approval framework.↗
- Australian Building Codes BoardNCC Part H2: Damp and weatherproofingRequirements for damp control, roofs and external waterproofing.↗
- New Zealand Building PerformanceE2 External moistureOfficial weathertightness requirements for roofs, walls and openings.↗
Stop if the work involves structural uncertainty, hazardous materials, heights, live services, gas, serious water damage, or regulated work. Local rules differ—use an appropriately licensed professional where required.