- What procedures should be followed for storing Poly-Flex liners at a jobsite?
Poly-Flex liners should be stored on a prepared ground that is free of rocks, roots, debris, or materials that may damage the liner. The rolls should also be stored away from standing water and should not be stacked more than two rolls high.
- How much liner is normally installed and tested in one day?
The amount of liner that can be installed and tested in one day depends upon site conditions, subgrade preparation and the difficulty of the project.
- Why do Poly-Flex liners have wrinkles?
Polyethylene liners expand and contract as the sheet temperature changes. This thermal expansion/contraction will cause the liner to grow or shrink with variance in temperature.
- What is the cold temperature resistance of Poly-Flex liners?
Poly-Flex liners pass the low temperature brittleness test at -70° C (-94° F) according to the ASTM D 746.
- Are there any ambient and/or sheet temperature limits when welding?
The industry standard is a maximum of 104°F measured 6 inches above the liner surface and a minimum of 32°F. The liner can be welded above the maximum and below the minimum temperatures if certain precautions are observed.
- How is the Poly-Flex liner deployed at the job site?
Poly-Flex liner is deployed using a lift system that suspends a roll off of the ground. The system is raised by a loader, forklift, crane or other lifting equipment and then spooled off and deployed. An unwind stand can also be used from a modified flatbed trailer. Please refer to Liner Panel Deployment detail under Technical Information.
- How are Poly-Flex liners held in place on side slopes?
The most common method of securing the liners on side slopes is by means of an anchor trench around the perimeter. The batten strip or the PEC embed channel systems are used to attach the liner to structures. Please refer to the Poly-Flex Design Details located in Technical Information.
- How much ballast is needed over exposed liners?
The ballast system should be designed to secure the liner in place under the maximum anticipated wind suction pressures for the specific project site. Wind uplift pressures can be as high as 30 psf depending on the project site geometry and wind velocity. Please call your Poly-Flex sales representative for more information.
- Can construction equipment be operated directly on the liner?
Equipment that applies less than 2 psi ground pressure can be operated directly on the liner when operated with caution, including no sudden starts, stops or turns.
- How much cover soil is needed before driving on the liner?
The minimum initial lift of cover soil should be determined based on the type of placement equipment, cover soil, and the liner system under consideration. A minimum of 15 - 30 cm (6 - 12 inches), is usually recommended for equipment with light ground pressure of less than 34.5 kPa . A higher initial lift height should be used for proportionally heavier equipment.
- Are there any adhesives, tapes or glues that are suitable for joining Poly-Flex liners?
There are no adhesives, tapes or glues that provide a permanent, watertight bond to polyethylene.
- What method is used for joining Poly-Flex liner panels together?
Poly-Flex liner panels are joined by two methods. The primary method of welding geomembrane panels together is fusion welding.
In fusion welding, heat is applied directly to the geomembrane panels by a motorized hot wedge welder. The panels are then routed through a series of rollers that fuse the material together.
The second method of joining Poly-Flex Liner panels is extrusion welding. This method is used primarily for performing repairs on the liner material. This method utilizes the application of molten polyethylene welding rod to the surface of the two geomembrane sheets to be joined. The molten extrudate creates a bond that seals the two pieces of geomembrane together
- Can Poly-Flex liners of different thickness or textures be welded to each other?
Yes. Poly-Flex liners with thickness or texture differences of 20 mils or less can be fusion welded together. Liners with thickness or texture differences of greater than 20 mils should be extrusion welded together.
- Can Poly-Flex liners of different densities be welded to each other?
Yes. Welding temperature adjustments must be made to achieve a successful weld. When extrusion welding, the lower density welding rod should be used.
- Can Poly-Flex seams be tested for leaks? How?
Yes. Poly-Flex seams are non-destructively tested over 100% of the seam length for leaks. The most common method is the air pressure test for dual wedge seams. The vacuum box test is used for extrusion welds.
- Can Poly-Flex liners be attached to fixed structures such as concrete, steel, pipes, etc? How?
Yes. Poly-Flex liners can be attached to fixed structures through a number of methods. With concrete structures, two methods are preferred. The first, to be used in new structures, is the Poly-Flex polyethylene embed channel (PEC). This channel can be inserted into a new concrete structure, providing for a three inch HDPE surface to which Poly-Flex liners may be welded creating a watertight seal.
Secondly, Poly-Flex liners may be attached to new and existing concrete structures through the use of stainless steel or aluminum batten strips. These strips are attached to the concrete by inserting stainless steel anchor bolts into the concrete, placing the geomembrane liner over the anchor bolts, placing a strip of neoprene gasket between the liner and batten strip, and securing the batten strip with washers and nuts. Poly-Flex liners may also be secured to penetrations through the liner by the fabrication and welding of a polyethylene " boot" around the structure. Please refer to the Design Details Section of Technical Information.
- What maintenance is required for Poly-Flex liners after installation?
None, Poly-Flex liners are maintenance free.
