To stop thermal bridging in an attic, what is recommended regarding the installation of insulation?

The recommendation to cover the tops of the attic floor joists with insulation effectively addresses the issue of thermal bridging. Thermal bridging occurs when materials that are more conductive, such as joists, allow heat to transfer more easily than the surrounding insulated areas. By ensuring that insulation envelopes the tops of these joists, it minimizes the path for heat loss or gain, thereby improving the overall thermal performance of the attic space.

When insulation is applied directly over the joists, it creates a continuous barrier that enhances the insulation's effectiveness. This approach helps to maintain a more stable temperature in the attic, ultimately leading to energy efficiency and comfort throughout the home. Proper insulation placement is crucial not just for efficiency but also for preventing problems such as ice dam formation on roofs and condensation issues in the attic, which can lead to moisture-related damage.

While placing insulation evenly throughout the attic or keeping it off the walls might seem effective, they do not directly address the problem of bridging as covering the joists does. Similarly, installing insulation in layers, while it may provide some benefit, is not a specific solution to thermal bridging and could create gaps that allow conduction through the joists.