Gutter overflow
Leaves, sediment, a blocked outlet or an undersized gutter can push rainwater behind the fascia and into wall or ceiling joints.
After the storm
Why does my roof leak only after heavy rain?
Heavy rain exposes weak points that stay dry in a short shower: overflowing gutters, wind-driven rain at flashing, blocked outlets, roof ponding and joints that cannot discharge water fast enough. The fix is to trace the water path, not simply seal the room where the stain appears.
Updated 13 July 2026 ยท Written by Cheong Seng, established in 1986.
Answer firstShort, practical guidance
Since 1986Roof and gutter workmanship
Klang ValleyHomes, shoplots and factories
Quick answer
Why does my roof leak only after heavy rain?
When a roof leaks only during a storm, check the roof edge, gutter capacity, downpipe outlet, flashing and any flat section that holds water. A leak that appears indoors after the rain stops can still have travelled from a roof or gutter detail several metres away.
Practical checklist
Common storm-related failure points
Flashing and tile movement
Wind-driven rain can enter wall junctions, extensions or shifted tiles when water is driven sideways across the roof.
Downpipe backflow or ponding
A restricted downpipe or flat roof that holds water can expose a weak joint, outlet or waterproofing layer.
Practical checklist
Capture evidence safely
Inside
Photograph the stain, drip point, bubbling paint or soft ceiling board. Do not touch wet electrical fittings.
Outside
From the ground, photograph the roof edge, overflowing gutter, downpipe and water trail on the wall.
Timing
Record when the drip starts and stops. Do not climb a wet roof or place a ladder against an unstable gutter.
FAQ
Questions people ask before booking
These answers explain what can be checked from photos and when an on-site inspection is needed.
Why is the ceiling wet after rain stops?
Water can remain in roof insulation, a wall joint, a slab or behind the fascia. The indoor timing does not prove that the ceiling is the entry point.
Can cleaning the gutter solve a heavy-rain leak?
Cleaning can solve overflow caused by debris, but repeated leaks may also involve slope, gutter size, joints, outlets or the roof detail above it.
Should I apply sealant immediately?
Photograph the area first and get the roof, flashing or gutter detail identified instead of hiding the source.
Contact Cheong Seng
Want a practical next step?
Send the property area, roof or gutter photos, and when the problem appears. Cheong Seng can advise the next inspection or repair step.
+60 12-323 6603