Are you aware of the extent of heat lost that can take place due to thermal steel bridging? Most people do not consider the thermal bridging process through the steel framework used in the building structure. They consider it as negligible and focus more on wall or door cavities. According to experts, approximately 20% of the heat loss occurs through steel thermal bridging in a non-insulated building. In an insulated environment, this loss could exceed 30%. Thus, it is crucial to achieve high thermal resistance for a low-energy consumption building.
How Does Thermal Bridging Take Place?
Simply put, thermal bridging occurs when metals with good heat conducting properties come in contact. It also occurs when a gap is created between two or more adjoining materials or surfaces. The most prominent thermal bridges are found at the junctions for:
- Cavity wall due to single lintel
- Tiles used to construct a wall or floor
Exterior walls are among the most common locations for the process of thermal bridging. Made up of light-gauge steel rods, the insulation property of exterior walls is reduced by almost 50%. Mostly, glass fibre sheets are installed between steel studs to increase insulation. However, the U-value (which measures the rate of heat transfer) is significantly high for glass sheets. They do little to enhance the insulation property of the building. The presence of cold spots in metallic sheets or rods also leads to ghosting. It is the process of dust particles being deposited on the wall due to the formation of a low temperature zone.
Also, there are integrated thermal bridges that occur due to the mechanical process involved in constructing a building. Usually, different components of a building are assembled through metal fittings. If not designed properly, these metal fittings acts as a thermal bridge that causes heat loss within the system.
Controlling Thermal Bridging for Better Insulation
It is essential to opt for a comprehensive insulation system inclusive of doors, walls, windows, roof, trickle vents and structural links made up of steel to control thermal bridging. The primary objective of thermal insulation is to curtail the heat conduction process from the building. By minimizing the potential conductivity of building components, it is possible to reduce heating and cooling expenses. However, complete thermal insulation is not possible due to the presence of the thermal bridging process.
Some of the effective insulation solutions to control thermal bridging are:
- Use cavity closers to seal gaps around walls and doors. One can also apply cavity fire barriers for enhancing insulation properties as well as protecting against a fire outbreak.
- Make use of aluminium frame assemblies for constructing the wall structure. When combined with multi-pane insulating glass units, the aluminium frame provides a thermal break in walls.
- Ensure the adjacent construction of insulating components used in windows. This will minimize heat loss due to small thermal breaks formed along window frames.
- To avoid thermal bridging through rooftops, insulate air ducts or handlers properly.
- Look for air leakage possibilities and fill the gaps with an insulating material.
One should give due consideration to installing a thermal break system at the time of constructing a building. Insulating a constructed structure requires more effort and investment. Make sure all insulating products are designed to work in a comprehensive manner and provide a continuous shield against heat loss.
For more information on advanced methods to control thermal bridging, visit http://www.cavalok.com. Cavalok is a leading cavity closer specialist in the UK. The company offer effective thermal bridging solutions in accordance with Accredited Construction Details (ACDs) and Enhanced Construction Details (ECDs). Cavalok cavity closers are used by leading UK builders as a definitive solution to thermal bridging at openings in cavity walls.
