Leadwork
Lead sheet weight from thickness (BS EN 12588 codes)
- where
- mass per square metre (kg/m²)
- lead thickness (mm)
- density of rolled lead (g/cm³)
- weight of the piece (kg)
- length of the piece or roll (m)
- width of the piece (mm)
Explain this equation
Gives the weight of rolled lead sheet from its thickness, per square metre and for a given piece or roll. Use it for ordering, pricing lead by weight or planning how to lift it.
A square metre of lead 1 mm thick is one litre of lead, and with density in g/cm³ that litre weighs ρ kilograms. So thickness in mm times density gives kg/m² directly. A piece is L_s metres by B millimetres, so dividing B by 1000 gives its area in m².
Mass is volume times density; the units happen to line up neatly for sheet material.
Sense check: Code 4 (1.80 mm) is about 20.4 kg/m², so a 3 m roll 150 mm wide weighs about 9.2 kg. Code 5 is about 25.4 kg/m².
Watch out: the code number is roughly the old weight in lb/ft², not the thickness. Always order by code and check the thickness matches the BS EN 12588 value.
Gives the weight per m² and the weight of a piece or roll of rolled lead from its code thickness, for ordering, handling and checking deliveries.
Enter your values to see the result.
Good to know
Rolled lead to BS EN 12588 is supplied in codes 3 to 8. The code number is roughly the old weight in lb/ft². Lead density is 11.34 g/cm³, and 1 mm × 1 g/cm³ is 1 kg/m², so code 4 (1.80 mm) weighs about 20.4 kg/m². Lighter codes (3 and 4) are typical for soakers and flashings; heavier codes go on valleys, gutters, flats and cladding. Choose the code for the detail and exposure from the Lead Sheet Association guidance.
Common mistake
Ordering by code alone and forgetting the weight. A 6 m roll of 600 mm code 6 weighs over 100 kg: plan for two-person or mechanical handling.
Limits
Nominal thickness; BS EN 12588 allows a tolerance. Supplier charts may round slightly differently.
Sources
Results are calculations from the published methods and figures shown, and depend on the data you enter. Follow the roof covering manufacturer’s fixing specification, BS 5534, BS 8000-6, BS 6229, the Lead Sheet Training Academy guidance and Building Regulations. Wind uplift and structural design need a competent designer.