A thermal bridge is a location in the building envelope where heat transfer differs from the surrounding construction, for example at an interruption or transition. The term is not a diagnosis that can be assigned to every cold area or damp mark.
During roof renewal, connections to walls, edges and other components may be relevant. Ask who assesses the construction relationships when insulation changes. A product value for the central roof plane does not automatically describe the behaviour of all its surrounding junctions.
Record observations such as local discolouration separately from suspicions about the cause. This website performs no thermal calculation or measurement. Appropriate investigation should identify the findings supporting its conclusion and any uncertainty that remains about the actual building and assembly.
Worth asking
Frequently asked questions
Is every cold patch a thermal bridge?
That cannot be established from touch alone. Appropriate assessment should clarify the cause.
Does an insulation product resolve every junction?
No. Junction details need consideration within the construction as a whole.