A radon gas and/or moisture abatement system (or method) is located under the concrete slab of a building. The system (or method) includes a multilayered mat having a first layer, a second layer, and a third layer sandwiched between the first layer and the second layer. The first layer is non-permeable and faces the concrete slab. The third (or sandwiched) layer is an entangled net. The second layer is permeable layer. The layers are bonded together. Whereby radon gas and/or moisture are inhibited from entering the building by passing through and collecting in the multilayer product.

A radon gas and/or moisture abatement system (or method) is located under the concrete slab of a building. The system (or method) includes a multilayered mat having a first layer, a second layer, and a third layer sandwiched between the first layer and the second layer. The first layer is non-permeable and faces the concrete slab. The third (or sandwiched) layer is an entangled net. The second layer is permeable layer. The layers are bonded together. Whereby radon gas and/or moisture are inhibited from entering the building by passing through and collecting in the multilayer product.