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Frequently Asked Questions


EPDM is not affected by low temperature extremes, even if exposed. It remains flexible and can be installed and seamed at below freezing temperatures (low temp resistance to -49° F/ 45° C).

EPDM is one of the puncture resistant materials available and exhibits elongation in excess of 500%. With careful placement, rounded rocks and boulders can be installed over EPDM liner but a geotextile cushion layer or layers should typically be laid between them and the liner.

Yes. The rubber surface texture provides excellent friction resistance to prevent soil sliding on the surface.

This synthetic rubber material is designed for decades of outdoor exposure to the elements and inert to the effects of buried environmental microorganisms.

An EPDM liner will survive exposure to a large variety of chemicals, even though the chemical could have some effects on the liner, without causing the liner to fail. If you have a specific concern, give us a call at 800-524-8672.


No, projects could vary from small (a few hundred square feet) to millions of feet of geomembrane.

HDPE requires trained technicians and special equipment. CLI's crews are certified and trained in the installation techniques.

HDPE can be obtained with National Sanitation Foundation (NSF) certification for suitability for contact with potable per NSF-61 Standard." Be sure to check availability before specifying HDPE in this application.

HDPE membranes are used as an impermeable flexible barrier to prevent contamination of the soil and groundwater by the chemical extraction solutions used in mining, as well as recapturing and recycling of solutions. If you have a specific concern, give us a call at 800-524-8672.

Because of the thermal expansion/ contraction due to variance in temperature will cause the liner to grow or shrink (approx. 2% over 100°F) causing a slightly "relaxed" wrinkling. It is advised to avoid wrinkling in any seam area.

HDPE is very rigid and tough and therefore difficult for rodents to bite. It is inert and does not contain potential nutrients such as plasticizers or reinforcing yarns that may be attractive to critters.


PVC outlasts and outperforms many traditional materials. Because 50% of its base polymer comes from common salt - an inexpensive, renewable resource - it is also much preferred to substitute materials that deplete natural resources.

A PVC liner covered with at least 12 inches of clean fill will last for decades. It must be protected from exposure to direct sunlight. (If the geomembrane must be exposed to direct sunlight, please look at other products for resistance to UV)

PVC liners resist root penetration. However, some vegetation could penetrate the liners. This can be avoided by sub grade soils prepared to be free of roots and organic material.

While PVC generally does not suffer from rodent attack, it does contain a component source protein plasticizer. Please note:

(1) PVC contains no compounds that have any nutritional or food value to rodents.

(2) the PVC materials do not contain any "addictive" substances.

(3) It is only possible to "chew" a geomembrane at an edge onto which an animal can grip. The likely reason for an animal chewing a geomembrane is to obtain access to the "other side" for some other reason.

A PVC liner will survive exposure to a large variety of chemicals, even though the chemical could have some effects on the liner, without causing the liner to fail. If you have a specific concern, give us a call at 800-524-8672.

30 mil PVC or greater already has an embossing on one side, processed during manufacture that provides a controlled pattern. This embossing helps PVC, already known for its flexibility, to conform to and 'grip' the contours of the ground.

Slopes should be no greater than 3:1 and require mechanically securing a liner by means of an anchor trench around the perimeter.

Garden pond projects and ornamental features can readily be self-installed using adhesives on any liner seams. If you have a large installation or have specific site needs and you need help, we can provide a range of assistance. Don't hesitate to contact us at 800-524-8672.

CLI tests its seam lengths for leaks (non-destructive testing) using air testing.

Yes, thermal contraction and expansion causes a liner to grow or shrink. The liner should be stretched over the prepared sub-grade and "pulled" taut and "relaxed" but not overstretched. However, care should be taken to avoid wrinkles in the seam area and around mechanical attachments.

Most of the time, if you can stand the temperature you are working in, so can the liner. Generally, if the temperature is above 104° or below 32° degrees, you can seam your liner if certain precautions are observed. At -25°, a PVC liner becomes less flexible for installation. If you are in doubt, CLI can help supervise installation or fully install your liner.

None, properly installed PVC liners are generally maintenance free.


These answers are provided as general information only and are not intended as a guarantee or warranty. Colorado Lining International assumes no responsibilities in connection with the use of this information.

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