Leadwork & flashing · A focused guide
Why is roof flashing pulling away from the wall?
Published by Big Ben Roofing Ltd
An open flashing-to-wall junction needs the flashing and its connection to the wall assessed together. A visible gap does not show whether the issue concerns retention, adjoining mortar, movement or a larger defect. Describe the affected length and any recent change without pulling the metal back into place. Ask the contractor to identify the cause and explain which wall and flashing work is included, rather than assuming a surface bead alone resolves it.
Document the connection, not just the gap
A wider photograph can show the roof slope, wall material and any nearby change of level. Say whether the gap appears along the full length or at one end, and whether previous sealant is visible. Share older repair records if available. Avoid reaching from a window to test the connection; an appropriately accessed inspection should determine what is loose and what remains sound.
Agree treatment of the adjoining wall
If the repair involves the joint where flashing enters the wall, ask what preparation and reinstatement are included. A local masonry problem may affect how the new or retained flashing can be secured. The quotation should explain any replacement length and connection to existing material. Where wider cracking is observed, ask whether separate building assessment is needed before the junction repair is finalised.
Useful details to record
- Identify the affected wall and approximate length of visible opening.
- Describe full-length separation differently from one loose corner or end.
- Mention older sealant patches or previous wall-junction repairs.
- Ask what adjoining masonry work is needed for the proposed connection.
Use information already available from indoors or ground level. Do not climb onto the roof or disturb materials to complete this checklist.
Does a gap beside the wall prove the lead itself has failed?
No. The condition of the material and the condition of its connection are separate questions. Ask the assessor to explain whether the existing flashing can be retained and what evidence supports repair or renewal of the junction.
Background reading
- Lead Sheet Training Academy: flashing and junction details
- SPAB: maintaining slate, tile and metal roofs
General guidance helps frame the questions. The cause, suitable materials and scope depend on inspection of the particular roof.
Related questions
What is the difference between step flashing and roof soakers?
Understand why visible wall flashing does not establish the condition of the separate detail beneath an adjoining slate or tile covering.
What should be considered when lead flashing keeps opening at a joint?
Ask about the layout and adjoining connections when a flashing joint repeatedly opens, rather than approving an unexplained rigid patch.
Discuss what you have noticed
Include your postcode, the affected roof section and when the concern appears. The team will review the enquiry and confirm the next step, scope and availability.
Request a roofing assessment