What Is Lead Roofing And Why Is It Still Used Today?
Lead is one of the oldest roofing materials in existence, and despite the vast range of modern alternatives now available, it remains the material of choice for a wide range of roofing applications across the UK.
From the valleys and flashings of traditional slate roofs to flat roof coverings and decorative architectural details, lead continues to be specified and installed by skilled roofers on both heritage properties and new builds alike.
Here is a look at what lead roofing involves and why it has stood the test of time so effectively.
What Is Lead Used For In Roofing?
Lead is a highly versatile material that is used in several different roofing applications, each requiring a different level of skill and experience to execute correctly.
Lead Flashings
Flashings are the strips of lead used to seal the junction between a roof covering and an adjacent vertical surface, such as a chimney stack, a parapet wall, a dormer cheek or a wall abutment.
These junctions are among the most vulnerable points on any roof, as they are where water is most likely to find a way into the building if the seal is not correctly formed and maintained.
Lead flashings, when correctly installed and dressed into the mortar joints of the adjacent masonry, create a durable, weather-tight seal that can last for many decades.
Valleys
Where two roof slopes meet at an angle, a valley is formed. Lead valley gutters channel water running down both slopes to the eaves, making sure it drains away effectively rather than pooling or finding its way into the roof structure.
Lead is the traditional material for valley gutters on natural slate roofs and remains the preferred choice on heritage and period properties where authenticity and longevity are priorities.
Flat Roof Coverings
Lead sheet is also used as a flat roof covering on porches, bay window roofs, extensions and other small flat or low-pitched roof areas. A well-laid lead flat roof, correctly detailed with the appropriate falls, drips and rolls to accommodate thermal movement, is one of the most durable flat roofing solutions available and can last for 50 years or more when properly installed.
Parapet & Gutter Details
On larger buildings, lead is frequently used for parapet cappings, box gutters and other architectural details where a material that can be easily shaped and dressed to complex profiles is required.
The malleability of lead makes it uniquely suited to these applications, as it can be worked around curves, corners and complex junctions in a way that rigid sheet materials cannot.
Why Is Lead Still The Preferred Choice?
Exceptional Longevity
The primary reason lead continues to be specified for roofing applications is its extraordinary longevity.
Correctly installed lead work on historic buildings has been shown to last for well over a century, and even on more typical residential and commercial properties a properly installed lead detail will outlast most of the alternatives available.
When the whole-life cost of a roofing detail is considered, lead's longevity makes it highly competitive against cheaper materials that may need replacing every 20 to 30 years.
Malleability & Versatility
Lead can be shaped, dressed and worked to fit virtually any profile or junction detail. This malleability means it can be used to solve complex weathering challenges that rigid or prefabricated materials cannot address, and it allows a skilled lead worker to produce beautifully finished details that are both functional and visually appropriate on heritage and traditional buildings.
Compatibility With Natural Slate
On natural slate roofs, which are the dominant roofing material across Cornwall and much of the South West, lead is the natural companion material for valleys, flashings and other details.
The two materials have been used together on Cornish buildings for centuries, and lead's longevity means it is well matched to the working life of a natural slate roof in a way that many modern alternatives are not.
Sustainability
Lead is a fully recyclable material. At the end of its working life, lead roof coverings and flashings can be melted down and reused without any loss of quality, making it one of the most sustainable roofing materials available from a whole-life perspective.
The Importance Of Skilled Lead Work
Lead roofing is a skilled trade that requires proper training and experience to execute correctly.
Incorrectly installed lead work, whether poorly dressed flashings, inadequately supported flat roof coverings or insufficient allowance for thermal movement, is a common source of roofing problems and can fail relatively quickly despite the inherent durability of the material itself.
Choosing a roofing contractor with specific experience and skill in lead work is essential to achieving a result that will perform as well as the material is capable of.