Rolled (Milled) Lead
To most people, lead sheet is all the same. Even some within the construction industry itself are not aware of the different types of lead sheet that are available today. This information page is designed to clarify the facts for property owners and managers, architects, specifiers, merchants and contractors.
Rolled (Milled) Lead Sheet to BSEN 12588:2006
Lead sheet has been produced by rolling since the mid 1700's and by the turn of this Century, rolled (milled) lead sheet was being used in the UK as an alternative to sand cast sheet for roofing and weathering.
Rolled lead sheet is formed by passing a slab of refined lead back and forth on a rolling mill between closing rollers, (nowadays often computer controlled) to a predetermined thickness. The sheet is then slit to width and cut to length for final packing and distribution.
Such is the consistency of the process that rolled sheet will not vary in thickness by more than +/- 5% at any given point.
Rolled lead sheet is the only type which is manufactured to a British and European Standard.
BSEN 12588:2006 specifies thickness tolerances and chemical composition in order to produce a consistent microstructure. The minimal variance in thickness means when fitted to a roof, the extent of thermal movement can be accurately predicted and the correct fixing method adopted.
The technical advice and literature of the Lead Sheet Association is based solely upon the use of rolled lead sheet to BSEN 12588:2006 and the design and construction of fully supported lead sheet roof and wall coverings (BS6915:2000).