Leaking Chimney? Chimney Flashing & Leadwork Repairs Explained

Leaking Chimney? Chimney Flashing & Leadwork Repairs

A leaking chimney can be difficult to diagnose because the place where water appears inside your home isn’t always where it is getting through the roof. Water around a chimney can enter through damaged lead flashing, deteriorated mortar joints, cracked render or problems with the chimney stack itself. It can then travel through the roof structure before appearing as a damp patch on a ceiling or wall. Finding the actual source of the leak is therefore an important part of any chimney leak repair. Simply treating the area where the water becomes visible may not solve the underlying problem.

At Easy Way Roofing, we carry out chimney repairs, leadwork and roof repairs across Central Scotland, starting with an inspection to establish where the problem is coming from.

What Causes a Chimney to Leak?

There isn’t one single cause of a leaking chimney. Chimneys are particularly exposed parts of a property and can gradually deteriorate through weathering. Some of the problems we commonly look for include:

• Damaged or deteriorated lead flashing around the chimney
• Cracked or missing mortar between bricks or stone
• Deteriorated pointing
• Cracks or defects in the chimney stack
• Damaged chimney pots or surrounding mortar
• Problems with the roof covering immediately around the chimney
• Previous repairs that are no longer keeping water out

Because several different defects can produce similar signs of water ingress, it’s important to inspect both the chimney and the surrounding roof rather than assuming where the leak is coming from.

What Is Chimney Flashing?

Chimney flashing forms the weatherproof junction between the chimney and the roof. Lead is traditionally used around chimneys because it can be shaped to follow the roof and chimney and, when correctly installed, provides a durable barrier against rainwater. Over time, however, leadwork can become damaged, lift or deteriorate. Problems can also occur where the lead meets the masonry or where previous repairs have been carried out incorrectly. When this happens, water may be able to penetrate around the chimney and enter the roof structure.

Can Damaged Chimney Flashing Cause a Roof Leak?

Yes. Damaged or defective flashing is one of the areas that should be checked when water is appearing around a chimney. Signs of a potential problem can include damp patches around a chimney breast, staining on ceilings or walls, water appearing during heavy rain or visible deterioration around the leadwork. However, these symptoms don’t automatically mean the flashing is responsible. Problems with pointing, masonry or the surrounding roof can cause very similar symptoms. A proper inspection can help determine whether a chimney flashing repair, another chimney repair or work to the surrounding roof is actually required.

Can Chimney Flashing Be Repaired?

That depends on its condition and the cause of the problem. Where the existing leadwork remains generally sound, it may be possible to carry out a localised repair. If the flashing is extensively deteriorated, incorrectly installed or has reached the end of its useful life, replacing the affected leadwork may provide a more appropriate long-term solution. We would always assess the existing flashing before recommending what work is necessary.

How Much Does Chimney Flashing Repair Cost?

The cost of repairing chimney flashing varies considerably between properties, which is why we don’t use a standard price for this type of work. Factors that can affect the cost include:

• The extent of the damaged leadwork
• Whether the existing flashing can be repaired or requires replacement
• The size and position of the chimney
• The type and condition of the surrounding roof
• Access to the chimney
• Scaffolding requirements
• Whether additional chimney or roof defects are discovered

For this reason, the best way to establish the cost of a chimney flashing repair is to have the roof and chimney inspected and receive a quotation based on the work actually required.

What About the Leadwork Around a Chimney?

Leadwork isn’t simply a cosmetic finishing detail. It plays an important role in preventing water from entering where the chimney passes through the roof. If lead flashing has lifted, split, deteriorated or is no longer properly sealed into the chimney, repairs may be necessary. The correct repair will depend on the existing installation. In some cases only a particular section requires attention; in others, more extensive replacement of the chimney leadwork may be appropriate.

Could the Chimney Pointing Be Causing the Leak?

Yes. The leadwork isn’t always the problem. Mortar joints between the bricks or stone of a chimney can deteriorate over time. Once pointing becomes loose, cracked or missing, the chimney becomes more vulnerable to water penetration. Repointing involves removing deteriorated mortar and replacing it appropriately to restore the joints and help protect the masonry. We’ve covered this separately in our guide to chimney repointing, including the signs that repointing may be required and the factors that affect its cost.

→ Read our guide to chimney repointing

How Do You Know Where a Chimney Leak Is Coming From?

This is often the difficult part. Where water appears internally doesn’t necessarily correspond with the exact point where it entered the roof. Water can travel along roof timbers, masonry and other parts of the structure before becoming visible. An inspection may therefore include checking the chimney stack, pointing, lead flashing, surrounding slates or tiles and other nearby roof details. That’s particularly important where previous repairs haven’t solved the problem. Identifying the underlying defect first can avoid repeatedly repairing the wrong area.

Does a Leaking Chimney Always Need Major Repairs?

No. The extent of the work depends entirely on what is causing the leak and the condition of the chimney. A relatively localised defect may require a straightforward repair, whereas a chimney with deteriorated masonry, pointing and leadwork may require more extensive work. We don’t recommend replacing sound materials unnecessarily. The aim is to identify the defect and determine the appropriate repair for the condition of the chimney.

Chimney Repairs & Leadwork Across Central Scotland

Easy Way Roofing carries out chimney repairs, chimney flashing repairs and leadwork throughout Central Scotland, including Glasgow, Edinburgh, Stirling, Falkirk, Alloa and surrounding areas. If you’ve noticed damp around your chimney, water entering during heavy rain or visible deterioration to the chimney or leadwork, we can inspect the roof and establish what is causing the problem.

We provide free roof surveys and estimates, allowing us to assess the work required before providing a quotation.

→ Find out more about our Chimney Repairs & Leadwork services

→ Find out more about our Roof Repair Services