Lead Waterproofing
Lead sheet is one of architecture's oldest and most proven waterproofing materials, manufactured to BS EN 12588 in thickness codes from Code 3 (1.32 mm) to Code 8 (3.55 mm). With a density of 11,340 kg/m3 and melting point of 327.5 degC, lead is the heaviest common architectural metal. Its exceptional malleability (Mohs hardness 1.5) allows it to be dressed to complex junctions, curved surfaces, and intricate architectural details that no other sheet metal can match. Lead forms a self-protecting lead carbonate patina that provides corrosion resistance for 100+ year lifespans. In Australian construction, lead sheet is classified non-combustible and is primarily used for heritage building restoration, specialised flashings, box gutters, and complex waterproofing details. IMPORTANT: Lead is a regulated hazardous substance under Australian WHS Regulations Part 7.2, requiring blood lead monitoring, PPE, and lead risk work assessments for workers. NCC 2022 restricts lead use upstream of zinc/aluminium-coated materials and prohibits lead on drinking water catchment roofs. While lead remains irreplaceable for certain heritage and complex waterproofing applications, its high embodied carbon (approximately 41 kg CO2-eq/m2), health hazards, and environmental concerns have led to alternatives being preferred for new construction where possible.
- Heritage Building Restoration
- Complex Waterproofing Details
- Box Gutter Linings
- Radiation Shielding
- Acoustic Barrier
Lead roofing dates to ancient Rome, with the Pantheon and numerous Roman baths using lead sheet. Medieval European cathedrals relied extensively on lead for roofing, gutters, and decorative elements. In Australia, colonial-era government buildings, churches, and institutional structures used lead roofing and flashings imported from British manufacturers. The development of machine-rolled lead sheet (replacing sand-cast) in the 19th century improved consistency and reduced cost. BS 1178 standardised lead sheet codes, later superseded by BS EN 12588. The Lead Sheet Association (UK) and Lead Contractors Association maintain installation standards. In Australia, lead use has declined for new construction since the late 20th century due to health and environmental concerns, with increasing preference for zinc, copper, and synthetic alternatives. However, heritage restoration work continues to specify lead where authenticity and proven long-term performance are required.
DISCLAIMER: This specification document is generated from the CLAD Materials Atlas Database. Information is for general guidance only and does not constitute professional engineering advice. Values are typical and may vary by batch, manufacturer, and production run. Verify suitability for specific project applications independently.