What does the term "thermal bridging" mean?

The term "thermal bridging" refers to a phenomenon where conductive materials allow heat to transfer through or bypass insulated areas, effectively reducing the overall thermal resistance of a building assembly. This occurs when a heat-conductive material, such as metal or wood, creates a pathway for heat to flow from one side of a wall, roof, or floor to the other without being impeded by insulation.

In the context of insulating a structure, thermal bridges can lead to increased energy loss and can potentially contribute to issues like condensation and mold growth, since certain areas may cool down more than others. Understanding thermal bridging is essential for insulation professionals, as it highlights the importance of careful design and installation practices to avoid situations where conductive materials compromise the effectiveness of insulation systems.

The other choices address various aspects of insulation and its installation but do not specifically capture the essence of how heat transfer is facilitated through conductive materials that bypass the insulating layers.