The lining system will only be as good as its supporting structure.

Care should be taken to match the right lining material with local site conditions.

Surface Preparations:
Surfaces should be level and free of all sharp rocks (all rock and stone greater than .05 diameter), objects, vegetation and stubble. (Soil sterilization may be necessary to kill roots and certain types of grasses.)

The subgrade surface should provide an unyielding foundation for the geomembrane with no sharp or abrupt changes or break in grade. Proper compaction assures stability and support of the liner.

Controlling Groundwater and Surface Moisture:
Standing water, mud, snow - any excessive moisture - is counterproductive for liner deployment and field seaming.

One method for controlling groundwater is to develop a French drain system under the lining system that allows the water to flow laterally under the lining without floating the lining.

Slopes:
Side slopes should be no steeper than 3:1 whenever feasible. Contact CLI directly when site specifications or conditions differ.

Slopes are usually hand-raked to achieve proper smoothness.

The lining system will only be as good as its supporting structure.

Care should be taken to match the right lining material with local site conditions.

Receipt of Liner and Materials:
Liner panels can be fabricated into large sheets to minimize field seaming. These large panels are first accordian folded, then rolled up on a core and strapped to a wooden pallet. Each pallet can be unloaded and transported by field fork equipment of sufficient capacity.

It is recommended that the liners panels' protective covering not be removed until installation and that any uncovered panels be stored out of direct sunlight.

Liner is shipped accordian folded and rolled onto a core, banded and notated.

The adhesives, solvents, pipe boots and other items are generally shipped with the panels.

Liner Deployment:
Sandbags (or similar ballast) are required to keep the panels in place during installation, exposed or covered - a minimum of 25 bags per panel.

All PVC liner should be covered with 12" of clean fill material as it is installed, working from the bottom to the top.

Liner is shipped accordian folded and rolled onto a core, banded and notated.

The adhesives, solvents, pipe boots and other items are generally shipped with the panels.

Anchor Trenches:
To secure the edges of the lining in an earthen pit, an "anchor trench" is dug. Anchor trenches are approx. two foot wide by two foot deep (2' x 2') and one foot back from the crest of the berm (standard trench dimensions and depth vary according to project design.)

Dirt removed should be raked out flat on the far side of the trench, away from the pit, to be used to backfill after the liner edges are laid out in the anchor trench, while allowing the panels to be unrolled along the berm.

Slightly rounding corners of the trench avoids sharp bends in the geomembrane. The trench itself needs to be free of loose soil and rocks.

Always take dirt to the outside of the trench.

Site Structures:
Structures, piping, concrete, drains, and any associated work should be completed prior to lining installation.

All piping, and retaining walls should be selected to work in tandem with the lining material chosen.

Panel Placement:
Take time when unloading and placing rolls of lining to avoid damage. Verify the location of a panel or sheet before unrolling and placement to avoid improper alignment.

Sandbags (or similar ballast) are required to keep the panels in place during installation - a minimum of 25 bags per panel.

Care should be taken to avoid wrinkles in the seam areas and around mechanical attachments.

It takes considerable manpower to deploy a liner. It is "pulled" but not stretched. Minor wrinkles insure the liner is installed in a relaxed condition.

PVC Field Seaming:
Pre-fabricating panels at our facility into essentially larger panels reduces the amount of field seaming a project requires. (Fabrication seaming is performed under controlled conditions and the seams are fully tested.)

The most commonly used field welding process with PVC is solvent welding, which is very similar to welding pipe and basically melts the adjacent panels together.

Now, with advanced technology in field welding, wedge welding is providing excellent seam properties and reproducible welds and is faster and cleaner than solvents.

CLI's use of wedge welders that apply heat and pressure to form a homogenous weld are becoming the state-of-the-art.

CLI has all the necessary welding equipment, along with certified technicians to install your project.

Pipe Boots:
A pipe boot is a "sleeve" that allows mechanical piping to be placed as needed without destroying the integrity of the liner.

An undersized hole is cut in the center of the sleeve, stretched over the pipe, creating a flange of material. Wrap pipe 12" and tie into flange of material. Stainless stell clamp sleeve to pipe.

Pipe boots can be pre-made to your liner type and outer-diameter pipe specifications. Shipped with the liner to your site, this step reduces field installation time.

Panels around piping penetrations are cut with rounded corners to prevent tear propagation.

90-degree and slope boots are also available.

Edge Treatment
As with all lining used in water applications, care should be taken to design a good edge transition from water to surrounding terrain. A safety bench and edge treatment are recommended.

The edge materials chosen, regardless of type (rock rip rap, concrete edge etc.) should work in tandem with the geomembrane.

Many projects utilize a safety bench designed at 3' below the operating surface. This bench solves several potential problems.

As the name implies, it allows someone who may fall into the water an area on which to stand and exit and it also creates an aesthetically pleasing finish.