Geomembranes

The geomembrane is the only material in the project that must not have a single defect. A geotextile with a defect filters slightly less effectively; a geomembrane with a single hole provides no waterproofing at all. That is why this category is judged on two aspects not shown on the quotation: welding and protection. Double-seam heat-welding leaves a test channel between the two seams, so that every metre of joint can be tested with compressed air — watertightness is proven, not merely assumed. And because the membrane almost always fails during installation, due to sharp aggregate particles, the protective geotextile is not optional.