Metals like copper are very attractive to thieves and are still used extensively in building projects. How can we best protect these valuable materials?

In the context of a building contract non-ferrous metals are usually copper, lead and aluminium. All of these materials are highly attractive to thieves because they are virtually untraceable and have a very ready cash market.
Other than keeping on-site the minimum amount of non-ferrous metals for daily use, it is a condition of most contract works policies that they are secured in a locked building or container overnight and at weekends.
Even when non-ferrous metals have been fitted as part of a heating system or a re-roofing exercise, it does not mean that they are no longer susceptible to thieves.
All of these materials are highly attractive to thieves because they are virtually untraceable and have a very ready cash market.
On a number of occasions, properties nearing completion have been entered and stripped of non-ferrous metals, causing water damage to the works and existing structure.