Fabricated geomembranes and cold weather

Geosynthetics | October 2011

By Andrew Mills

One of the key advantages of fabricated geomembranes is the ability to take large sheets into the field to minimize field welding. Nowhere is this more important than in cold or wet weather.

As winter moves in, installation conditions can deteriorate rapidly from rain, snow, and cold conditions. Moving the welding of the geomembrane out of the field and into the shop makes sense in these situations.

On smaller projects, fabricated geomembranes are sometimes delivered to the jobsite in one piece. One-piece liners work well for oilfield pit liners, secondary containments, remediation pads, and small ponds.

Prefabricated single panel sizes can range from 22,000ft² for heavy reinforced geomembranes to more than 100,000ft² for lightweight reinforced geomembranes (based on 5,000lb panel sizes). One-piece prefabricated liners bypass the problems of field welding entirely, allowing jobs to go ahead in even the most difficult weather conditions.

There is a perception that field welding can’t take place at temperatures lower than freezing. While it’s true that some field-fabricated geomembranes are best not welded in the cold, a number of shop-fabricated geomembranes can be welded in all temperatures. Many fabricated geomembranes are flexible in the cold and are not adversely affected by welding in cold weather. Fabricated geomembrane materials have been installed and welded in temperatures as low as -40 (C or F).

Large prefabricated flexible panels can also speed installation in poor weather. Flexible prefabricated geomembranes are often assembled in a staging area and then deployed across ponds full of water to create floating covers. This same technique has been used in poor weather to deploy liners into ponds where standing water has been holding up welding or to even deploy the geomembrane directly onto a pond covered with a layer of snow.

More clients are specifying cold weather installation with prefabricated geomembrane liners. Irrigation canals are one application where all work takes place in the winter off-season. In the high Arctic, clients are creating temporary secondary containments, using ice as their building material and white geomembranes to prevent the ice from melting during service.

Working when everything is frozen can be an advantage because it is easier to protect streams and waterways from construction silts and sediments when there is a cap of ice. Tailings dams have been built at remote sites in the dead of winter using fabricated geomembranes where summer construction would have been much more difficult.

Fabricated geomembranes provide a variety of materials that can address the needs of winter installation, including cold and wet weather. The variety of fabricated geomembranes and the ability to make large panels mean that there is likely a fabricated geomembrane that will be right for your project.

Andrew Mills is Research and Development Manager, Layfield Group, in Edmonton, A.B., Canada. He is the current FGI president.

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