Norman & Underwood is the UK’s largest and oldest manufacturer of traditional sand cast lead. Our craftsmen still produce lead sheet by hand using the same processes employed for hundreds of years.
Sand Cast Lead
On restoration projects, it is vital to use traditional sand cast lead to match the existing roofing and cladding materials. In most cases, we actually remove and recast the existing lead. But many architects and clients still prefer sand cast to milled lead on new build projects because of its more attractive sheen and colour.
At Norman & Underwood we have been sand casting lead to order in the same way for almost two hundred years.
The casting table is filled with a mixture of two types of sand – sharp white sand which allows the steam created by the molten lead to pass through the sand bed, and pulverised red moulding sand to hold the grains of together.
Using a strickle – a bar of wood with a handle at each end – the lead casters ram and solidify the sand bed and plane it off to required depth. They then smooth the surface using hand-held copper planes.
The lead is melted in a crucible and ladled into a steel head pan. When the casters lower the handle, the overhead wheel rotates and tilts the head pan, pouring the molten lead down the sand bed.
While the molten lead is still running, the casters move the strickle down the length of the table to plane the lead to the required thickness. Once the lead has solidified, the sheets are rolled up ready for despatch to site.
The sand bed is then totally re-made and dampened for the next cast of lead.
The quality of our sand cast lead is guaranteed through strict BS EN9001: 2005 quality assurance procedures. It is produced to tolerances of +/- 5% for thickness and weight – the same standards as those of rolled lead manufacturers.