How to investigate a roof leak

What to do when water comes in

Keep people clear of a sagging or bulging ceiling and water near electrical fittings. Arrange urgent help for these conditions. Move belongings only where access is safe, and photograph the affected area for the repair and any insurance enquiry.

Do not climb onto a wet roof or enter an unsafe roof space. Roof access, fragile materials and electrical hazards need a competent inspection plan. An interior stain is useful evidence, but it does not identify the failed tile or flashing by itself.

Build a short leak record

• Which room and where on the ceiling or wall the water appears.
• Whether it occurs during rain, later, or in dry weather too.
• Wind direction, storm intensity and any hail at the time.
• Previous roof repairs, solar installation or other recent work.
• Visible gutter overflow or drainage problems seen from ground level.

Send both a close photo and a wider view that locates the stain. Dry-weather leaks may require a plumbing investigation; roof-space condensation is another possible source of moisture.

What the inspection should establish

Ask the roofer to inspect the relevant roof covering, junctions, flashings, penetrations, gutters and outlets. Water can travel along surfaces before appearing indoors, so the inspection needs to connect the entry point with the damage.

The report should identify observed defects, inaccessible areas and any tests needed. A controlled water test may help in suitable conditions, but it should not expose occupants, electrics or the building to avoidable damage.

Cleaning blocked drainage and repairing a failed junction are different from coating the whole roof. Request photos and a repair description before approving a broad waterproofing proposal. Use the waterproofing comparison when a membrane system is actually indicated.

Price the diagnosis and repair separately

Use the roof repair price guide for inspection and repair estimates. Access equipment, widespread damage and structural work can increase the total substantially. Confirm any inspection-fee credit in the written quote; it is not automatic.

The quote should name the defect, preparation, materials, access, waste removal and the method of checking completion. Interior ceiling repairs and redecorating may be separate, and should follow resolution of the leak and appropriate drying.

For a complex, have the managing agent confirm the relevant property boundary, approval route and responsibility before work starts. Keep the inspection findings and scope with the maintenance records.