Page 22 - Curriculum Visions Dynamic Book

Lead for buildings
Lead has many natural advantages for building. It has been widely used in the past and continues to be used today.
Lead’s properties are ideal for building: it is waterproof, soft and easily moulded into awkward corners that cannot
be filled by other materials. It is heavy, holding the roof of a building down even in high winds, and it does not corrode, so a lead roof will remain in good repair for many centuries.
In the Middle Ages, most cathedral roofs in Europe were made of sheet lead, which is why they have a dull grey appearance. The lead roof of a cathedral in Istanbul, Turkey, is known to have lasted without repair for over 1400 years.
Lead is also used for protecting buried cables and for sealing cast iron pipes in some sewage systems.
Lead in water systems
The word plumbing is derived from the Latin word for lead, plumbum.
For many centuries people did not have any idea that lead was a danger to health. They could not detect the minute amounts of lead compounds that dissolved in water, and so people could only see the advantages of the metal.
One of the main needs was to get water from rivers or reservoirs to homes inside cities. The Romans were one of the first civilisations to achieve this, carrying water cross-country in long stone aqueducts. However, these open waterways were of no use in the city; instead, pipes were needed to bring water to homes. Some pipes were made of naturally hollow materials such as bamboo, or cast materials such as clay, but most pipes were moulded from lead because it was soft, did not corrode, and could be easily shaped to go round bends and other difficult areas of buildings. One pipe could also be joined to another very easily.
Although the Romans were the first to use them, lead water pipes continued to be used for most plumbing systems well into the present century. It was only quite recently that the possible dangers of lead in pipes became known. Today millions of homes are still supplied by water through lead pipes.
Also:
There are many, and sometimes confusing, uses of the word lead in connection with glass. The earliest use may be when, in about 1675, the English glassmaker Ravenscroft developed “glass of lead” which was more durable than the glass then being made. Lead crystal is glass containing enough lead to alter the refractive index, while leaded glass refers to the way glass panes are fixed with lead strips.
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