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Geomembrane specifications: What civil engineers should know about the specs used for every project

News | May 15, 2020 | By:

Specifications are the bedrock of geomembrane development, fabrication and installation. But for engineers on the receiving end of new projects and geomembranes, specifications can often breed confusion. Unfortunately, there are many outdated specifications in use today that can cause headaches during installation. Today, we’ll explain why it’s essential to use the current guidelines and find the right specs for your project.

Why are there so many outdated specs?

It is alarmingly common for geomembrane projects today to be based on outdated specs. For example, PVC is one of the most commonly specified materials for a wide range of applications. But, the most common spec in use for PVC is from 2004, even though industry organizations have released three new specification versions since then.

A lot of the confusion simply comes down to a lack of awareness of the specification updates. 

This is particularly problematic as the generation gap grows between older and younger geomembrane project engineers. Many veteran engineers don’t want to know or learn about new geosynthetic materials. That has meant that there are fewer guides to teach updated specs to young engineers starting out in the industry.

Using current specs matters

Unfortunately, using outdated specs has consequences for geomembrane installations. Using the incorrect material for a specific project can lead to wrinkles, shrinkage, or welding issues. These problems are often costly and time-consuming to fix in the field. Worse, they can compromise the integrity of a geomembrane installation if they’re not dealt with appropriately.

Outdated specs can also raise the overall cost of a geomembrane installation

Relying on guidelines that are decades old often means opting for more expensive geomembrane materials. Specification updates typically reflect best practices for the use of more modern, cost-effective geomembrane materials.

Finding the right specs for your project

When it comes to getting the right specifications for a particular geomembrane installation, there are three main sources.

ASTM International

ASTM International is primarily composed of materials producers. This organization offers specifications based on geomembrane materials that won’t undergo fabrication.


The Fabricated Geomembrane Institute (FGI) is a coalition of geomembrane fabricators. FGI modifies ASTM International specs to reflect the extra processing and treatment that geomembranes undergo during fabrication.


The International Association of Geosynthetic Installers (IAGI) is comprised of engineers, field installers, and welders. IAGI is an organization that has long been the standard-bearer of specs used by civil engineers.

Using up-to-date FGI and IAGI specs for your projects

In recent years, FGI and IAGI have come together to produce unified standards. These updated specifications better reflect the capabilities of fabricated geomembranes. Using up-to-date FGI and IAGI specs for your projects is the best way to avoid costly headaches down the road.

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