What Is Roof Flashing And How Do You Know It Needs Repairing?

Roof flashing is one of those parts of a roof that most homeowners rarely think about until water starts getting in. It is usually fitted around vulnerable junctions where roof coverings meet another surface, helping direct rainwater away from gaps that would otherwise be difficult to keep watertight.

Lead is commonly used for flashing because it can be shaped around roof details and, when installed properly, provides a durable weatherproof finish. Like any exposed roofing material, though, flashing can eventually become damaged or start to fail.

Where Is Roof Flashing Used?

You will often see flashing around chimney stacks, where the chimney passes through the roof covering. It is also used where a pitched roof meets a wall, around certain roof junctions and in details where water needs to be guided safely onto the roof covering and towards the guttering.

The exact arrangement depends on the roof, but its purpose is broadly the same: to stop water entering at joints and changes in level where tiles or slates alone cannot create a reliable seal.

What Does Failed Flashing Look Like?

Some problems are visible from ground level, while others only become clear during a roof inspection. Flashing may lift away from brickwork, become split, develop holes or lose the secure detail that keeps it in position.

Mortar around leadwork can also deteriorate. If the lead itself is still serviceable but the surrounding joint has failed, water may still find a route behind it.

Older leadwork can show signs of fatigue after years of movement and weather exposure. The important thing is to assess the whole detail rather than assuming every leak around a chimney is caused by the same fault.

Damp Around A Chimney Can Be A Warning Sign

If damp patches appear on a chimney breast, ceiling or wall near the stack, damaged flashing is one possible cause. It is not the only one. Worn chimney pointing, damaged masonry, cracked flaunching and other defects can also allow water into the same area.

This is why chimney leaks need to be inspected properly. Bastion Roofing provides chimney, leadwork and roofline repairs, looking at the condition of the stack and the surrounding roof details rather than simply treating the most obvious symptom.

Can Flashing Be Repaired?

Often, yes. The right repair depends on what has failed and the condition of the existing material. A small localised problem may be repairable without replacing every section of leadwork around the roof.

Where flashing has become badly damaged, incorrectly fitted or reached the end of its useful life, replacement may be the more sensible option. The surrounding roof covering and masonry also need to be considered, particularly around older chimney stacks.

Why Temporary Sealants Are Not Always The Answer

Roofing sealants can look like a quick solution to a leaking joint, but covering a problem without identifying the cause can make future repairs more awkward. A short-term patch may also fail again if the lead is moving, split or no longer correctly fixed.

A lasting repair should deal with the detail that is allowing water through, whether that is the flashing itself, the joint into the wall or another nearby roofing fault.

What About Valleys And Other Roof Junctions?

Not every water-sensitive roof detail is chimney flashing. Valleys, abutments and roof intersections all have their own methods of directing water away safely. Leaves, debris, cracked materials or failed joints can create problems in these areas too.

If water is appearing indoors near a roof junction, the visible location inside the property does not always tell you exactly where the external defect is. Water can travel before it becomes visible.

Should Flashing Be Checked After Bad Weather?

If you have noticed a new leak after strong wind or heavy rain, it is sensible to have the affected area checked. You may also spot lifted materials or movement around the stack from ground level, but avoid climbing onto the roof to investigate.

For broader leaks and roofing faults, our roof repair service covers damaged tiles, flashing, ridges, verges and other common causes of water ingress.

Get The Cause Confirmed Before Repairing It

There is no benefit in replacing good leadwork if the problem is actually cracked pointing, and equally there is little value in repointing a joint if the flashing beneath it has failed. A proper inspection should separate those issues and recommend the repair that is actually needed.

If you have damp around a chimney, visible damage to leadwork or a roof leak that seems to be coming from a junction, contact Bastion Roofing for straightforward advice and a free, no-obligation quote.