Define Thermal Bridging & Prevent Energy Loss with Polyamide Strips

To define thermal bridging is to describe a localized phenomenon in a building assembly where there is a significantly increased transfer of heat due to materials of high thermal conductivity penetrating or bypassing the thermal insulation layer. It is a discontinuity in the otherwise uniform thermal resistance of a wall, roof, or floor. This breach creates a path of least resistance for heat flow. The formal definition hinges on the comparison between the intended, insulated assembly and the compromised one at the bridge location. The key metric is the linear thermal transmittance, or Psi-value (Ψ-value), which quantifies the additional heat loss per meter length of the thermal bridge, beyond what is calculated for the plain areas. The process of defining thermal bridging also involves understanding its two primary types: repeating thermal bridges, which occur at regular intervals (like wall studs in a frame wall), and non-repeating (or geometric) thermal bridges, which occur at junctions like corners or around openings. The definition is not complete without acknowledging the consequences: elevated energy use, reduced interior surface temperatures, condensation risk, and compromised occupant comfort and health. Therefore, to define thermal bridging is to articulate a critical building pathology that necessitates deliberate design intervention to ensure the construction of efficient, durable, and healthy structures.