What should be avoided in electrical installations in hollow spaces to prevent the spread of fire?

Avoiding a substantially increased risk in electrical installations within hollow spaces is critical to preventing the spread of fire. Hollow spaces, such as wall cavities or ceilings, can act as pathways for flames and smoke, making it essential to ensure that any electrical work is done properly to minimize fire hazards.

The correct response highlights the importance of maintaining safety standards in electrical installations. When risks are exacerbated due to improper installation techniques or materials, the potential for a fire to spread rapidly increases. This need for caution is supported by the provisions within the National Electrical Code, which emphasizes safety and quality standards to mitigate fire risks.

Improper techniques or the use of non-compliant materials can contribute to increasing fire risks, but the focus on avoiding a substantially increased risk speaks to the broader principle of ensuring that electrical installations do not create conditions that could lead to fire spreading through these hidden spaces.