4.3.14 - The effects of animals, insects and plants

Cables may be subject to damage by animals and plants as well as from their environment. Rodents in particular seem to have a particular taste for some types of cable sheathing and can gnaw through sheath and insulation to expose the conductors. Cables impregnated with repellent chemicals are not often effective and may also fall foul of the Health and Safety Regulations. Rodents build nests, often of flammable materials, leading to a fire hazard. Care should be taken to avoid cable installation along possible vermin runs, but where this cannot be avoided, steel conduit may be the answer.

Mechanical damage to wiring systems by larger animals such as cattle and horses can often be prevented by careful siting of cable runs and outlets. Attention must also be given to the fact that waste products from animals may be corrosive. Access by insects is difficult to prevent, but vent holes can be sealed with breathers. Damage by plants is a possible hazard, the effect of tree roots on small lighting columns being an obvious problem area.