Is your thatched roof leaking? 7 common causes worth checking

1. Opened or loosened surface

Density is crucial on the outer layer of a thatched roof. If areas open, loosen or begin to thin, rainwater can travel deeper. At first this may appear only as occasional leakage, but it can later affect wider sections.

2. Damaged ridge or edge formation

The ridge and edges are among the most sensitive parts of the roof. If covering breaks down there, water can often enter faster than across the broad roof planes.

3. Delayed effects of earlier storm damage

Not every storm defect is obvious immediately. Wind, hail or a broken branch may cause local damage that only becomes visible during the next heavier rain.

4. Ageing or unevenly worn surfaces

Older roofs do not always age uniformly. Certain sides or strips may deteriorate faster because of weather exposure, so leaks can appear locally while the rest still looks acceptable.

5. Poor drainage or unfavourable geometry

If water cannot run off properly, or leaves more slowly at transitions and lower-pitched areas, the risk of leakage increases. Junctions and older structural compromises often deserve careful attention.

6. Earlier poor repair or temporary solution

Sometimes a leak is the return of a previously half-solved problem. Incompatible materials or superficial patching may calm the owner briefly while making the long-term situation worse.

7. Hidden junction defect

A leak does not always appear where the real defect is. Moisture entering at a flashing, penetration or sensitive junction may travel before becoming visible inside.

When should you call immediately?

• the same room leaks repeatedly
• visible damage exists at the ridge or edges
• the problem first appeared after a storm
• an interior damp patch is growing quickly
• you cannot tell whether the issue is local or widespread

A quick assessment often determines whether a targeted repair is enough or a larger intervention should already be considered.

Summary

Several different causes can sit behind a leaking thatched roof, and many are still manageable when identified early. The priority is not guessing, but finding the real cause as soon as possible.