The lead flashing that seals the join between your chimney and the roof is one of the most common sources of roof leaks. Lead is extremely durable — a well-formed flashing can last 50 years or more — but it does not last forever, and when it fails it lets water straight into the roof and rooms below. Here is how to tell when your chimney lead flashing needs replacing.
Visible cracks and splits
Lead expands and contracts with temperature. If it has been fixed without allowing for that movement, or the wrong thickness (code) has been used, it work-hardens and splits. Visible cracks in the flashing are a clear sign it needs renewing. See our leadwork page.
Leaks around the chimney
Damp or water staining near a chimney breast, inside or in the loft, often points to failed flashing. Because water travels, the damp may appear below or to the side of the chimney rather than directly under it.
Lifting or loose flashing
If the lead is lifting away from the chimney or the tiles, it is no longer sealing the joint properly. Wind, age and poor fixing all contribute. A flashing that has come loose needs attention before it lets water in.
Age and the wrong lead code
Older flashings simply reach the end of their life. Some fail early because the wrong lead code was used — too thin for the application — or because it was fixed without allowing for thermal movement. We replace it with the correct code and detailing.
Why specialist leadwork matters
Renewing chimney flashing is skilled work. The lead must be dressed and welded to a weathertight standard, with the correct code and movement allowed for, and integrated properly with the tiles or slates. A quick patch rarely lasts. Arrange a survey through our quote form or see our chimney repairs page.
Frequently asked questions
How long does chimney lead flashing last?
Correctly installed lead flashing of the right code, with movement allowed for, can last 50 years or more. Premature failure is usually down to the wrong thickness or poor dressing.
Why has my lead flashing cracked?
Lead expands and contracts with temperature. If fixed without allowing for movement, or the wrong thickness is used, it work-hardens and splits. We replace it with the correct code and detailing.