What is the primary function of the gas-permeable layer in a sub-slab depressurization system?

The primary function of the gas-permeable layer in a sub-slab depressurization system is to allow for soil gas movement. This layer is crucial in creating a pathway for radon and other soil gases to enter the system and be effectively drawn away from the living environment. By permitting the movement of these gases, the system can effectively reduce the concentration of radon in a home or building, helping to improve indoor air quality and decrease health risks associated with radon exposure.

The gas-permeable layer is typically made of a material that can easily allow gas to flow through it while also providing structural support for the system. Its design and placement are integral components of the depressurization system's overall efficiency, ensuring that the gases can be collected and vented out safely and effectively.

In contrast, while drainage and aesthetic considerations may be relevant in general construction practices, they do not capture the specific, critical purpose of the gas-permeable layer in this context.