What evidence should I ask to see before agreeing to roof repairs?

Photographs should show the defect, be dated, and be identifiable — which elevation, which detail, where in relation to something recognisable. A folder of anonymous close-ups is not evidence about your roof.

Where a drone survey has been used, the images should cover whole elevations as well as the defects, so you can see context rather than only the worst spot.

A defect and a symptom are two separate facts. The value is in the link between them: how this failure produces the damp patch in that room, and why that route is more likely than the alternatives.

Where the link is not certain, a straight answer is better than confidence. Being told that the cause is probable and needs confirming is useful information; being told a roof needs replacing without the reasoning is not.

Ask what makes replacement necessary rather than repair: what proportion of the roof is affected, which components are failing generally, and what a repair would and would not achieve. Ask whether partial renewal of one slope would serve.

There is nothing wrong with a replacement recommendation that comes with reasoning. There is a great deal wrong with one that does not.

Ask how the roof space was accessed, whether any water testing was carried out, and how long the inspection actually took, since a diagnosis reached in a few minutes from the ground is a different thing from one that included a look inside. None of this needs to be adversarial; a contractor confident in their findings should be glad to answer it.

It is also fair to ask what would change the recommendation, for example what a repair would need to show for replacement to be reconsidered, since this reveals whether the recommendation was actually evidence-led.

Beyond naming the work, a scope should say what materials will be used, roughly what is included and excluded, and what happens if something unexpected is found once access begins, such as decayed decking under a covering that looked sound. Agreeing this in advance avoids disputes later about what was originally promised.

A short paragraph covering these points is normally enough; the absence of any such paragraph is itself informative, since a contractor who has genuinely thought through the scope will usually have no difficulty setting it out in writing before asking for a decision.