Several different types of metal can form strong termite shields, including copper, galvanized steel and galvanized iron. Termite shields are included in some new home construction as a tool to help identify termite infestations. Copper termite shields or shields made from other metals do not prevent termite infestations – they just make infestations more easily detected.
Why Choose Copper Termite Shields?
When copper is exposed to air over time, the outer layer oxidizes. In some metals, oxidation causes rust. However, when copper oxidizes, it forms a greenish layer called a patina. This layer protects the copper from further oxidation. Because copper resists corrosion, it is a good metal to use as a termite shield. Moisture-loving termites can cause other types of metal to corrode more quickly.
Some builders prefer to use copper termite shields instead of galvanized steel or galvanized iron termite shields because copper is an easy metal to work with during construction. Although copper is more malleable than other metals, it still is a durable metal and makes a strong termite shield.
Copper is impenetrable to most subterranean termites. However, there is some evidence that Formosan termites can chew through very thin copper sheeting. Therefore, you should ensure that the copper shield is at least 4 millimeters thick to prevent termites from destroying this barrier.
History of Termites and Copper Control Measures
Copper has played other major roles in the history of termite control besides its uses in termite shields. Copper has been used as an insecticide and as a protective wood treatment, when mixed with other materials.
Chromated copper arsenate (CCA), which includes arsenic and copper, formerly was used to treat wood. It is no longer used for residential construction because the chemicals in CCA can leach into water sources. Today, wood used in residential construction may be treated with Copper Azole (ACQ) or Micronized Copper Quaternary (MCQ) to make the wood unappealing to termites.