Wouldn´t a thicker or even double liner be better?
No, a thicker liner would not be effective. The flexible nature of the 40-mil material allows it to move if settlement occurs or there are seismic events. Further, a “double” liner as some have proposed would not improve performance of the containment system. Having two layers adjacent to one another could actually decrease the liner life if water or air were to get trapped between the layers. A single liner is a proven and reliable barrier because very strict protocols are used for testing the seams and overall integrity of the liner during installation. The manufacturer provides specialized personnel to oversee the installation, and Georgia-Pacific and DTSC provide additional quality control requirements and oversight.
