Why can the visible roof defect be different from the actual cause?
The short answer
Because the obvious fault is not always the operative one. A cracked slate may be visible while water is entering at a flashing out of sight. A defect may also be a symptom of something else — slipping caused by batten decay, for example. The visible fault is where investigation starts, not where it ends.
What evidence should you look for?
An obvious defect that does not correspond to where damp appears inside.
- What it can mean
- The real entry point may be elsewhere.
- What else could explain it
- Water travels, so a distant defect can still be the cause — the connection has to be shown.
Investigate · Inspection needed to confirm
What could this mean?
Test any diagnosis against the symptoms. If the proposed cause does not explain when and where water appears, it is probably not the whole story.
What this evidence cannot tell you
Establishing a cause properly may need loft inspection during rain, or a controlled water test, rather than a single visit in dry weather.
Related services
What should you do next?
Ask how the identified defect explains your particular symptoms, including the weather conditions in which they appear.
Reviewed by Aaron, Owner, Elite Roofing Services Cumbria Ltd — last reviewed .
Related questions
More in Understanding Roof Evidence
- What photographs should a roofer show me before I agree to repairs?
- Can photographs prove where my roof is leaking?
- What should a photograph of failed roof flashing show?
- What does a slipped slate look like?
- What does deteriorated leadwork look like?
- Can photographs tell me whether a roof needs replacing?
- Should a roofer show me photographs after completing the repair?
- How can I tell whether roofing photographs are actually from my property?