Why Is My Flat Roof Leaking?
Updated 2026-03-01 · Written by the Town & Country Roofing team
Why Is My Flat Roof Leaking?
The most common causes of flat-roof failure — and how to tell if repair or replacement is the answer.
Flat-roof leaks are almost always at the details, not the field: upstands, drips, penetrations and rooflight kerbs.
Torch-on felt fails at laps and welts as it ages. EPDM fails at seams and detail work if installed poorly. GRP fails at cracks over deck movement.
A pooled area of standing water often indicates a fall or drainage problem, which can shorten the life of any membrane.
If the deck is sound and the failure is localised, repair is often practical. If the membrane is at end-of-life and the deck is soft, replacement is better value.
More on problems
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What to Do When Your Roof Is Leaking
A step-by-step plan for the first hour of a roof leak — including what NOT to do.
What to Do After Storm Damage
Safe checks, insurance evidence and how to prioritise repairs after a major storm.
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