# Thermal Bridging PDF for Civil Engineering Seminar Report

Understand the concept of thermal bridging and construction details which influence thermal bridging. The PDF papers will guide the civil engineering students to prepare seminar report and explain the concept of thermal bridging and provide examples of thermal bridges using case studies.

### What are Thermal Bridges?

Thermal bridges are particular points where heat loss is accentuated relative to other parts of a building such as floors, walls, and ceilings. Thermal bridges typically occur at the junction of different building components where it is difficult to achieve continuity in the thermal insulation layer. A major factor in the performance of the building fabric is not simply the amount of insulation you install, but how it interconnects with other components and the other insulated elements within the design. Building junctions, where building elements meet such as at corners or reveals are less well insulated than the main element.
It has been estimated that up to 30% of the heat loss in a well-insulated building is through these 'Non Repeating Thermal Bridges' at wall/floor junctions, corners, reveals, ceiling heads and sills etc. It is critical that when calculating the performance of low energy buildings that this heat loss is measured and minimized.

### Types of Thermal Bridges

Thermal bridges are categorized into three types, Repeating, Non-Repeating and Random.
Repeating Thermal Bridges A common repeating thermal bridge is where timber studs bridge a layer of insulation in a cavity wall. As this occurs regularly throughout the element, ie the wall, this is deemed a repeating bridge and must be accounted for in the U Value calculation for the element by making the appropriate corrections.
Non-Repeating Thermal Bridges A non-repeating thermal bridge would be, for example, where the ground floor and external wall joins, a common bridge here is where the insulation in the wall and the floor do not join, forming a cold bridge at the corner. This type of thermal bridge needs to be accounted for in any SAP calculation as the combined heat loss from non-repeating thermal bridges over an entire building can account for up to 15% of the total.  If the building thermal envelopes have very low U Values and the junctions between each are not accounted for in the design details, the percentage of heat loss through the non-repeating bridges increases.
The visual effect of cold bridging is condensation forming in the corners of rooms, and mold growing in due course. This is particularly a problem where external corners are exposed to the cold, or if internally wardrobes and other furniture obscure corners and there is little movement of warm air to circulate.
Random Thermal Bridging Random bridging is where there is a one-off bridge, for example, a steel beam in a wall construction. These are dealt with in SAP by applying a procedure to account for it in the U Value calculation. However, good building practice would dictate that this type of bridge be minimized as much as possible.