Q: What is GSE HD?

A:  GSE HD is a smooth, high quality, high density polyethylene (HDPE) geomembrane liner. It is made with resins specifically designed for geomembrane production. All varieties of GSE HDPE geomembranes including GSE HD Textured, GSE Smooth Edge Textured, GSE White, GSE White Textured, GSE Conductive, GSE Conductive Textured and GSE Green Textured meet or exceed the material property requirements in GRI GM13 for HDPE geomembranes.

Q: What are the benefits of using GSE HD?

A:  GSE HD has an extensive proven record as one of the premier HDPE materials available with thousands of successful installations. GSE HD is produced with resins designed to provide superior performance in physical properties, resistance to stress-cracking and long term performance, in both exposed and buried applications.

Q: What is GSE HD Textured?

A:  GSE HD Textured is the textured version of GSE HD. The textured surface(s) is produced using GSE’s coextrusion processing equipment. The texture is applied to one or two sides of the liner and is an integral component of a three-layer coextruded geomembrane. GSE HD Textured combines the exceptional durability of HDPE liners with a roughened surface that provides very good frictional characteristics against a variety of soils and geosynthetic surfaces.

Q: Why use a textured liner?

A:  Textured liners provide increased friction between the liner/soil interfaces as well as between the liner and other geosynthetics. This increase in friction helps keep cover soil in place and improves the overall liner stability on slopes.

Q: If I order GSE HD Textured, how will the thickness be measured?

A:  During the manufacturing process the thickness of the textured sheet is continuously monitored to ensure that the core layer is the proper thickness. Textured thickness is tested with a point micrometer probe for “valley to valley” thickness measurements per ASTM D 5994.

Q: What is GSE HD Smooth Edge Textured?

A:  GSE HD Smooth Edge Textured is another textured version of GSE HD. GSE Smooth Edge Textured has two textured surfaces produced using GSE's coextrusion processing equipment. GSE HD Smooth Edge Textured has the same properties as GSE HD Textured with the added benefit of the smooth edges which allow for faster and easier welding.

Q: What are GSE White and GSE White Textured?

A:  They are high quality GSE HD and GSE HD Textured geomembranes that have an upper white, light reflective surface. The white surface is approximately 5 mils thick and part of the overall geomembrane thickness.

Q: What are the benefits of using a white surfaced geomembrane vs. a black geomembrane?

A:  The white surface reflects radiant heat thereby reducing liner temperature and reducing the amount of wrinkling caused by thermal expansion. Mechanical damage that exposes the underlying black layer makes such damage much easier to identify.

Q: How much less will the white wrinkle compared to black liner?

A:  The amount of wrinkling is a function of the change (increase) of temperature. In many instances, reflection of radiant energy reduces wrinkles in GSE White by 50% or more.

Q: For what type of applications would I use a white surfaced geomembrane?

A:  GSE White can be used in any application where a black HDPE liner is required.

Q: Can I use GSE White on exposed applications?

A:  Yes. GSE White is formulated to be highly resistant to UV degradation and can be used on exposed applications. While black geomembrane will have a longer life than white, accelerated laboratory tests indicate an estimated lifetime of 18-50 years for the white surface in exposed conditions.

Q: Can the white surface delaminate from the black base sheet?

A:  No. GSE White is a coextruded material making the white surface an integral part of the membrane.

Q: What is GSE Conductive Geomembrane?

A:  A patented geomembrane that incorporates into its construction a conductive layer which can be utilized for post installation surface inspection.

Q: What are the benefits of using GSE Conductive?

A:  GSE Conductive has a proven record as one of the premier HDPE materials available. In addition to all of the normal benefits of using GSE HD materials; superior performance in physical properties, resistance to stress-cracking and good long term performance, in both exposed and buried applications, GSE Conductive offers 100% post-installation inspection using an easy and economical method.

Q: Does dirt or water on the liner invalidate the test?

A:  A small amount of dirt or water on the liner surface typically has no effect on the spark test. However, when the spark test electrode comes in contact with a conductor on top of the liner (such as water or dirt) with a sufficient surface area, that conductor can behave in the same manner as the spark test grounding pad and discharge through the sheet. As a result, there will be a false indication that there is a hole. In that case, simply remove the water or dirt and retest the area. If testing is required over fill material, other methods must be employed.

Q: Is GSE Conductive Textured available in double sided textured?

A:  No. In order to assure a continuous conductive surface, the surface must be smooth. Only single-sided GSE Conductive Textured is available. In order to conduct a spark test, the smooth side must be down and the textured side up.

Q: Is the testing of this system safe to the technicians?

A:  Although the test voltage is very high (15000 to 35000 volts), virtually no current (AMPS) is involved. GSE is very concerned about the safety of our technicians and they are extensively trained for this testing.

Q: Competitive bidding is required on my project. If defect testing is specified, will this not eliminate competitive bids?

A:  The well-known electric leak survey is a valid test procedure, and is available to all bidders as a defect test procedure. There are alternative testing methods available including visual inspection, vacuum box and water flooding. However, the GSE method provides an extremely accurate and quick method to save the customer time and money in his inspection fees.

Q: Will re-permitting or variances be required to use conductive liner on projects previously permitted?

A:  This will vary with the different permitting agencies and regulatory bodies. However, since the basic liner properties and specification do not change, and the ability to test for defects prior to use represent enhanced value in the liner, it is very likely that regulators will look favorably on the use of this material.

Q: What is GSE Green Textured?

A:  GSE Green Textured is a high quality double sided textured GSE HD Textured geomembrane with an upper green surface. The upper surface is green to improve the aesthetics in Exposed Geomembrane Cover Systems (ECGS).