To stop a flat-roof leak properly, identify the external defect before choosing the repair. The damp mark or drip inside is evidence of water ingress, but water may have travelled beneath the covering before reaching that point.
Step 1: make the situation safe
Do not climb onto a wet, icy, fragile or unsafe roof. Keep clear of unsafe ceilings and water near electrical fittings.
Step 2: narrow the source
When conditions are safe, inspect cracks, splits, seams, edges, wall junctions, rooflights, outlets and penetrations. Note whether the leak follows heavy rain, wind-driven rain or prolonged ponding.
Step 3: assess the surrounding roof
A local defect can sometimes be repaired without treating the entire roof, but widespread deterioration, a soft deck or structural movement changes the decision.
Step 4: choose an appropriate repair
For a compatible local defect, a reinforced liquid repair can combine waterproofing liquid with separate fleece reinforcement across the prepared repair area.
SealForge Kit
For an appropriate localised flat-roof defect, the SealForge Kit supplies polyurethane liquid repair material, 1m² fleece reinforcement, primer, catalyst and application tools. Price: £129.99 plus delivery.
Use the Flat Roof Leak Help Centre for detailed diagnosis and follow the supplied technical information before application.