Leaks & repairs

How do I find where a roof leak is coming from?

Short answer: Start with the internal entry point, trace moisture upslope where safe and compare it with external junctions, but avoid walking on the roof yourself.

35-second explainer

Wet loft: leak or condensation?

A 35-second guide to damp lofts: record the timing, understand clues and gather evidence safely before choosing a repair.

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General guidance. A property-specific inspection may be needed.

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Read the video transcript

Wet loft? Leak or condensation? A damp loft does not automatically mean your roof is leaking. Start with the pattern.

Cold mornings. Lots of droplets? Condensation can form when moist air meets a cold surface. The pattern is a clue. It is not proof.

After rain? Record the timing. Note when dampness appears and whether wind changes it. Rain entry and condensation can happen together.

Before you book a repair, record when the damp appears, take photos from a safe position and keep details of previous repairs. Do not climb onto the roof to investigate. An inspection may be needed to establish the cause.

Get a straight roofing answer. Use the roof problem checker at northeastroofanswers.co.uk. Need help with your property? Enquire directly with J&L Welch. General guidance, not a diagnosis.

What this means in practice

Water can travel along underlay, rafters and battens before it appears indoors, so the stain is a clue rather than proof of the entry point. A sound diagnosis combines the weather pattern, an internal loft inspection and a close external check of the covering and every nearby junction.

What to check next

  • Record when the leak occurs
  • Inspect loft timbers and underlay safely
  • Use external photographs or a professional survey

When should you ask a roofer to inspect it?

Book an inspection when a leak is active or recurring, the source is unclear, timber or insulation is staying wet, or a previous patch has failed. Water near electrics, a sagging ceiling or loose material above a public area needs urgent attention.

Safety first: do not climb onto a roof without suitable access, training and protection. Keep clear of loose coverings, unstable ceilings and water near electrical fittings.

About this guidancePublished by J & L Welch Roofing & Paving Services Ltd. General information, not an assessment of your roof.Content updated 28 August 2026 · How our answers are produced

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