Leadwork
Milled lead
Sheet lead has been produced since the mid 1700's and rolled
(milled) lead is an alternative method of lead production for
roofing and weathering of roofs and walls in the main.
Rolled lead sheet is the only type of lead sheet that is
manufactured to a British and European Standard and the production
process is so consistent that the thickness will not vary by more
than +/- 5% at any given point.
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.
Sand cast lead
Sand cast sheet lead is mostly hand produced and is made by
pouring molten lead across a prepared bed of sand and then
"skimming" it to the required thickness. It is still produced
mainly for its rough grain aesthetic appearance or where a historic
property requires replacement or restoration to its original
look.
Cathedrals, churches and period buildings originally used sand
cast sheet lead for their roofs and drainage systems. As history
has shown it has outstanding durability when fitted correctly. This
longevity is mainly due to its thickness and weight, with a 12"
(305 mm) square typically weighing 6-8lbs ( 2.7 -3.6kg).
Sand cast sheet however is not produced to any fixed chemical
composition, it is not made to any British and European Standard
either and it does not have an Agrément Certificate so a full
assessment of what roofing material would best suit any project is
highly recommended.
Copper
Copper is another of the hard metals used for roofing for its
excellent durability and often for its pleasing aesthetic
appearance. Although slightly more expensive than equivalent
alternatives it is no doubt, one of the most prestigious roofing
finishes to have and presents more of a challenge to work with due
to its less than malleable nature.
Zinc, Aluminum and stainless steel
Most popular economy hard metal roof solution and often chosen
for large expanses. Manufactured in many colours and finishes these
metals are popular choices for industrial projects.
NSE are experts in assessing the technical suitability and
capabilities for any given project and are experts in working with
milled and sand cast lead in all of its applications.
Download a weight chart to better understand the complexities of
this metal or contact our office to discuss your requirements
further.
http://www.midlandlead.co.uk/order_form/weightchart.pdf