A thermal bridge is a pathway through insulation where heat transfers more rapidly than through surrounding materials, reducing overall insulation effectiveness. Common thermal bridges occur at wall studs, floor joists, roof rafters, and metal fasteners that conduct heat directly between interior and exterior spaces. Thermal bridges can reduce insulation performance by 5-15 percent in typical construction.
Types and Examples
Structural thermal bridges include wood or steel framing elements that bypass insulation layers. Thermal bridges also occur at building joints, window frames, door frames, and continuous metal elements like balconies or metal roof decking. Attic access hatches, penetrations for plumbing and electrical systems, and exposed concrete slabs create additional thermal bridge pathways.
Reduction Strategies
Continuous exterior insulation, thermal break materials, and strategic framing reduce thermal bridge effects. Techniques include using foam sheathing over studs, insulated sheathing, and thermal break strips in metal-frame systems. Proper insulation installation around penetrations and openings minimizes thermal bridging losses and improves overall building energy performance.