Thermal bridge investigation
The local weakening or disruption of a thermal-insulating layer are described as thermal bridges. In practice, they occur in a variety of forms.
Often, external building components cannot be completely insulated thermally, or only with a locally reduced thickness; for example, if a statically necessary support penetrates the thermally insulated roof or if the space required for installing an insulating layer simply is not available. When it comes to the energy efficient building renovation of old structures with structured façades that are listed as historic monuments, thermal insulation is frequently fitted on the interior side of the outer wall. Thermal bridges arise in those places where this interior thermal insulation must end at the intersecting floor slab, outer wall, and inner walls.
When exterior temperatures are low, the building component in the area of a thermal bridge can cool down to the extent that the inside air humidity condenses on the surface of the building component to form 'condensation'. Persistent or frequently recurring humidity eventually results in a build-up of mould, with the possibility of wood rot.
From a planning aspect, thermal bridges cannot be completely avoided, and do not cause damage in every case. However, a detailed inspection is always advisable.
At the planning stage, we use special calculation methods and tools to investigate critical points. Finite element software (FE) assists us in modelling critical structures in two or three-dimensions on the computer. Energy loss and temperature distribution are investigated on the model, evaluated in terms of possible condensation formation, and if necessary optimised to ensure that no adverse effects are expected.
Such FE-calculations are possible for both steady and transient states. Transient modelling can provide answers for questions concerning fire protection, e.g. the time-dependent temperature distribution in building components in the event of fire.